© Copyright Brian Lambert
Firstly a word of warning.... Never, ever allow mains power (230v a.c. in the UK) to go onto the railways baseboard's. If 230 volts is allowed onto the baseboard there is a very serious risk of electrocution and possible death. Only safe extra low voltage should be here. Mains supplies and all the associated transformers should be housed in commercially made or expertly produced safety enclosures. These should either be 'floor' or 'off layout' mounted. Umbilical multicore cables or individual wires then supply the appropriate low voltage power supplies onto the layout.
The only exception to this rule is where a controller has a mains input supply requirement and then the mains power is fed to the controller via a flexible mains cable and at times via a special three pin "Kettle" or "Computer" type mains plug and socket in the casing of the controller. e.g. The Hornby HM2000 has such a requirement. The mains cable and all its connectors that feed the controller should be regularly inspected for any signs of damage and any noted should render that supply cable or controller unit unusable until it is replaced or professionally repaired.
Now perhaps is the time to start thinking of how the final layout will operate. Will there be just one operator or more? One or more mimic control panels or basic controller locations. Assuming for all these discussions from here on, just one control point has been decided upon and provision for at least two operators provided, though one person can operate the layout single-handedly, if need be. Draw out your track plan and then start to consider where track power feeds will be required and where any Isolating sections will need to be installed. Remember on dc layouts always feed the track power into a set of points from the tip or switch blade end, NEVER back feed from the frog direction. When using Live Frog (Electrofrog) points you should install two rail isolating breaks, one in each rail after the frog ideally at the two Vee rail ends leading away from the frog. Where a pair of Electrofrog point make up a cross-over both rails where the two points abut each other will have insulated rail joiners fitted. Don't forget when using live frog (Electrofrog) points on a passing loop etc you should always insert an insulated rail break at both ends of the loop ideally at the ends of the Vee rails from the points, as this prevents any electrical short circuit problems occurring. If you're using Insulated frog (Insulfrog) points such as Hornby, Peco Setrack or their Streamline Insulfrog "SL" versions then the use of Insulated joiners is all but removed, expect for isolating track sections. On these type of points the frog and point blades switch the rail power and they are self isolating, providing track power only to the direction the point is set to. But the dc electrical feed must flow into the point tip first, is still a necessity. See the section below on Points for more details.
The Beginnings.... Many will come into the hobby with a basic train set layout. Often an oval of pre curved track and a few straight sections making up the basic layout. Inside the train set's box will normally be a plug-in mains adaptor to safely reduce the mains supply to around 12 to 16 volts. A controller to enable the operator to control the speed and direction of the train, a locomotive, coaches and/or wagons and the track, plus quite often a power connecting clip or a special length of straight track that has the tracks power connection built in. While this simple system will proved the basics and give enjoyment for many hours, there is often the need to improve over and above that of the basic train set. So the beginner returns to the model shop and purchases more track to make another loop and perhaps a point or two. They assemble the new outer loop and connect the two tracks together via a new cross-over set of points, then wonder why the inner or outer loop doesn't work or occasionally stops for some reason.
The main reason is that a second controller is required for the new loop. So from the basic train set set-up we now progressed to having a twin tracked railway controlled by two independent controllers. Sidings are then added and perhaps a third loop or even a high level section with track passing over one or more of the lower lines and eventually rejoining the main loop elsewhere. All really good fun and what a wonderful way to enjoy oneself and perhaps enrol the family members too.
But the need to control the layout further and in more detail is now required. The builder probably wants to be able to stop one loco in the platform and then shunt the trucks or coaches off into a siding by using another loco. Perhaps in another siding there is a twin tracked loco shed and it would be good to be able to run several locos into the shed, storing them one behind the other without the first one moving. But this siding is fed from the main line by a set of points which are right at the back of the layout, so electric point control is needed too. We now need several isolating track sections and a few electrically operated point motors. These options are quite straight forward and on a dc controlled layout you will have to start wiring and installing insulated track sections (Isolating sections) and wiring specially switched feeds to them and even install your chosen type of electric point motor and the means of switching the power to them.
OK, the above is very simplistic and perhaps not how your layout has come to be. But the basic idea is the same, in that at some time in the overall hobby of model railways you will have to carry out at least some basic electrical wiring. So don't be put off. Not knowing an amp from a volt or ac from dc isn't a means of preventing any further work. Hopefully the following items should help you understand how all this comes together and how the layout works.
Electrical Basics.... Our model railway is powered at a safe nominal 12 volts direct current (dc), the exception being DCC layouts which use around 14 to 16 v ac and even this isn't a true form of ac! The 12 volt dc can come from a couple of sources, such as a battery (car batteries and dry cells were used many years ago) or more commonly now from a mains to safe extra low voltage 'plug into the wall socket' power pack or perhaps a via a directly fed mains powered single, twin or more knob controller. So, each 'controller' allows for totally separate operation of a section of railway track via its control knob or slider. The more you turn up the controllers knob more of the nominal 12volts is provided to the rails. e.g. from 0 volts slowly up to maximum volts of around 12v. Note; the actual full voltage supplied may be higher than the nominal 12volts. Some basic controllers can exceed 20v dc when turned on and no locos are on the rails - i.e. No load voltage. It is conventional to have the right-hand rail, when looking along the loco towards the front, at a positive potential to obtain forward travel. As previously stated, some controllers have one knob thereby powering only one track, while others can have up to four controller knobs allowing four separate tracks to be fed and independently controlled from each other. The output to the track from the controller is called the 'Controlled' output. In addition some makes of mains powered controllers also offer other outputs which are not controlled by a knob or slider, such as a 16 volt alternating current (ac) output and / or a 12 volt dc output. These are both called 'Uncontrolled' outputs.
These additional outputs are used to supply power to other functions. The 16v ac supply is normally used to power point motors (Solenoids) via special switches. While the 12v dc being quite often used to supply such items as building internal illumination, street or platform lighting, powering turntable motors or even feeding another slave and non mains powered controller. More of all this detail later...
Below is shown the basic means of connecting the output of the train controller to the rails. Two wires run from the controlled output terminals on the controller to the rails. To make the rail end connection as easy as practicable, the manufactures of the track produce 'power clips' which can be simply pushed into the gaps under the rails and between the sleeper spacing webbing. The top of the connector touching the underside of the appropriate rail allowing a very easy push fit electrical connection to be made. The stripped end of the wire simply plugs into the receptacle in the end of the clip. The alternative to the 'plug in' power clip is the powered track section. This is normally a short length of straight fixed section track with built in power connecting terminals. All three styles are shown below.
Of course there is another way of connecting the track power feed wires to the rails, and that is by soldering the wires directly to the outer web of the rails or to the undersides of the rails if the track has still to be laid in position. See the examples under the heading Track feeds further below.
On dc powered layouts the standard is that when the right-hand rail is positive and looking along a loco from the cab end towards the front or chimney end on steam outline locos the loco will move forwards.
This simple drawing shows the idea.....
Peco SL273 “OO” track power clips
Shown above is the Hornby "OO" power clip
A Hornby "OO" track section with pre fitted power connector
RETURN CONNECTIONS In the two drawings below, examples of point motors return wiring are shown, the upper drawing shows terminal blocks being used to allow individual motor return wires to connect together along a common return bus wire. In the lower drawing a common return bus wire is shown with each motors return wire connection being a twisted and soldered joint onto the bus wire. I would recommend where the common bus wire method is used to increase the wire size used for the bus. 32/0.2mm should be ideal or a solid copper wire such as 1.0mm2 or 1.5mm2 removed from former mains cable. Note: While Hornby R044 black point levers (passing contact lever switches) are shown, the principle applies to all types of point operation switches.
Peco have a surface mounting point motor which resembles to some degree a real point motor. This motor comes supplied with three coloured lengths of wire attached. On the PL11 the wiring colours are Red operation one way, Black operation to the opposite way and Green is the return wire. Below is show a PL11 wired to a passing contact switch, i.e. Hornby R044, Peco PL26 or a sprung to centre SPDT toggle switch and also shown is the alternative to these via a the use of momentary push to make (non locking) push buttons.
The basic wiring for multiple point motors and their switching is shown below. While five motors are drawn they are operated by four switches, more switches and motors can be added. Note the use of a CDU to enable better point operating performance. Where two motors are required to operate together e.g. a cross-over pair of points, then the two motors are be connected together and worked by one switch or lever as shown with the left-hand pair of motors.
One wire point operation circuit can be made which removes the need for a CDU and also allows the use of SPDT (Single Pole Double Throw) switch which can, if desired, be built into a mimic control panel or Console. The advantage here is that after throwing the point the switch remains in that position, therefore its toggle or lever indicates the position of the point. A passing contact or centre off switch is not required. Note this circuit should have between a 1000uF to 2200uF electrolytic capacitor in series with the two diodes. Failure to fit a capacitor will result in the motor being permanently connected to the supply and this will lead to rapid coil burn-out. I opted for a 1000uF capacitor per motor and this gives a good pulse to the coil of all my Peco PL10 and Seep PM1 motors. However, some circuit builders have reported, especially where PL11 motors are being used, that a 2200uF capacitor is better! Ensure the two diodes are fitted with opposite polarity to each other. I use a former laptop 19v volt power supply and the circuit works best when 16 to 24 volts dc is used as the power source. Use 16/02mm or 24/02mm wire throughout.
If the motor throws the opposite way to the switches toggle position then reverse either the Positive and Negative connections on the switch or swap over the diode wires where they connect to the motor coil terminals.
The above circuit should only be attempted by those who understand electrolytic capacitors and switching of supplies.
Stall Motors can be wired from either a 12 volt or less dc supply or alternatively from a 14 to 16 volt or less ac supply. They work, unlike solenoid motors, by continuous power being fed to their internal electric motors. Once the motor has moved over the motor continues to draw a small current (typically 10 to 15milliamps) from the supply, this is known as the 'Stall Current' and this stall current holds the point motor over in the position selected. Note that this style of motor uses a panel switch to operate its motor that is always 'On' e.g. SPDT or DPDT On-On toggle switches as these provide the required continuous supply to the motor. Ideally 12 volts dc or even a little less voltage (down to around 10v) is used as this allows the motor to slowly move over and back both more quietly and more prototypically too. They cannot be used directly from an ac power source, hence the two diodes fitted into the ac operation circuit below.
So for dc power use DPDT switches and for ac power supplies use the two diodes and SPDT switches.
Below are two simple methods of wiring Stall type Motor Points
The drawing immediately above shows a very simple Stud & Probe switching method. While the upper drawing shows dedicated point switches (Centre Off Sprung to centre) toggle switches being used, but this could equally be replaced by a pair of push-to-make non locking push buttons. Note that the two drawings offer the choice of 16 or 24 volt ac supply (24v is my preferred voltage) but a 16 to 24 volt dc supply can equally as well be used. A CDU is shown in both, which I recommend. If the CDU is omitted then the wires from the PSU continue directly to the probe or switch and to the motors return connection.
Below is shown how the Stud & Probe are fitted into the mimic panel facia and wires from each stud underneath the panel run off to the appropriate point motors coil. Note the recommended use of a CDU in the Probes feed. Where a cross-over pair of points are used, three studs are employed - one in each route. The two straight ahead route studs are wired together, so touching either one will power the two point motors of the cross-over 'Normal' (straight through running). The actual studs can be commercially available items or simply M2 or M3 round headed machine screws of suitable length, with a washer and nut fitted underneath. The wires to the motors coils are then either soldered to the stud or held in place by being sandwiched between a further pair of washers and a locking nut.
Momentarily touching the probes live end onto the appropriate stud supplies the power to that motors coil
Typical Solenoid Point Motor Wiring using Stud and Probe
Below shows a CDU (optional) feeding a bank of point toggle switches and then feeding out to the appropriate solenoid motors.
Inside the Hornby R044 Black passing contact point lever switch....
With the Hornby R044, power is taken into the lever switch via the central lower connection which also acts as the pivot for the lever, then as the lever is moved from its rest Off position it immediately makes connection On-1 with the first contact strip and sends power to the point motor coil, but this coil on the point motor is already in the point closed position, hence a little "Buzz" is often heard from the motor as the lever starts to move. Then as the lever is in its middle travel it is in the Off position. Next the lever makes connection to the opposite contact On-2 and provides an electrical path to the point motors other coil, powering the solenoid motor and moving point over. Finally the lever comes to rest and breaks the connection and is in the Off position at rest. So from one side to the other the point switch contacts are from Off - (On-1) - (Off) - (On-2) - Off. Note bracketed items cannot remain in that position. They are called 'Momentary' or 'Passing' connections.
The above 'double connection' produced by the R044 point lever is a problem where a CDU is to be used. As the CDU has to discharge into the first connection and motors coil (On-1) and then the CDU doesn't have time to fully recharge before the second and required contact (On-2) is reached.
In this case, it is advisable to hold the R044 lever in the central area of its travel for a second or two to allow the CDU to fully recharge before finally allowing the lever to be moved fully across the rest of its travel. Thereby allowing a the now recharged CDU to discharge via the passing contact (On-2) and energising the correct motors coil and moving the point over, before the lever finally comes to rest in the Off position.
The above 'double connection' arrangement does not occur with the Peco PL26 point lever switch, as this uses a totally different switching method and it only provides one momentary pulse of power to the correct motors coil during the levers full travel.
Similarly point motor wiring can be switched via Sprung to centre off toggle switches, Studs and Probe, or push to make non locking push buttons. Two the these are shown below.
Same R044 Passing Contact Lever but with a Capacitor Discharge Unit and connection terminal blocks added
As previously but now using the Peco PL26 Passing Contact Lever etc
Hint:- Click on any image to view it larger.
Below is the basic wiring configuration for both the Hornby R8243 and the Peco PL11 surface mounting motors. Note that each make uses different coloured wires for their operation and return connections.
The very basics.... Hornby R044 Passing Contact Lever
Point Motor Wiring. Many layouts will use electric point motors, in my case I use Peco and Seep ones, but there are many other makes of solenoid motors available. They all work on the same simple principle. Apply a short burst of electrical power to a coil and an electromagnetic field is created. Place the coil around a tubular former and put a piece of iron (Iron core) inside the formers tube. Now when coil 1 is momentarily energised the core is pulled across into that coils tube by the electromagnetic field created. Then apply momentary power to coil 2 - the opposite coil, the iron core flies across into that coils tube. Now fit a drive pin centrally on the iron core and connect the pin to the points moving tie bar and you have a means of electrically moving the point over and back.
The next item to consider is how these will operate and the wiring needed. I opted originally for stud and probe point control via my layouts mimic control panel, but I have since changed to sprung to centre off position toggle switches. But there are several other methods of switching the point motor feed - Hornby R044 black lever switch or the Peco PL26 are both passing contact levers and are just two of those readily available. Equally pres to make non locking push button can be used, here two per point are needed.
For improved solenoid motor performance consider installing a Capacitor Discharge Unit. One Capacitor Discharge Unit (CDU) is normally used to feed the whole layouts point motors and this provides that extra pulse of power to move the solenoid motor, these are wired directly across the 16 to 24 volt point power supply transformers output. I prefer the use of 24 volt a.c. for point operation via a CDU, but there’s no reason why the 16 volt a.c. supply or any voltage ac or dc between 12 and 24volts couldn’t be used equally as well. Using a CDU reduces the current drawn from the transformer and also protects the solenoid motor/s coils from any possible continuous powering which can rapidly lead to eventually motor coil burn out. So, I advocate always investing in a CDU, they actually cost little more than two new solenoid motors! They should be available from all good model railway shops or you can if wished make your own.
The drawings below show very simple arrangements of one point motor and either a passing contact lever, Stud and Probe or a switch - sprung to central off, and a CDU all powered from a 16v to 24v ac transformer. You will of course need to operate more than one point on a layout and all that happens is more studs or switches, Red & Green wires plus a return wire are installed. Touching the relevant stud with the probe allows the CDU to fire a 'one shot' discharge current through the appropriate stud and wiring and out onto the motors coil winding, or if using switches the momentarily closing of the switches contact operates the circuit. However, only passing contact, momentary or sprung loaded centre off switches must be used, otherwise the motors coil would receive full power continuously and quickly burn out, though a CDU will help to prevent this happening. When two or more sets of points are need to be operated at once, as is the case in a cross-over pair of points, then simply wire one motor onto the other, ensuring the electrical path for the two point motors direction is correctly orientated and wired on both point motors. Most CDUs can operate up to three or four motors simultaneously and those sold as "Heavy Duty" often can throw up to six or seven motors at once. Though I wouldn't like to do this, as quite high currents will start to be needed and the wiring probably will not allow such to occur (volt drop and current limitations). Anyway, why should there be any need for seven points all to operate at once? It's better to re design the circuitry and allow only two or three to operate simultaneously.
There are several other methods to operate points electrically than using the Stud and Probe or dedicated point lever switches. Push buttons of the 'push to make non locking' type are available quite cheaply and also Sub Miniature spring toggle switches of either the Double Pole Double Throw (DPDT) centre off type or Single Pole Double Throw (SPDT) centre off can be used. Maplin Electronics part numbers FH03D or FH07H refer. I personally dislike push buttons such as the Maplin FH59P (Red low cost Push button) as they often ultimately tend to suffer with burnt-out contacts, however 'contact burn' isn't such an issue where a CDU is used. The sprung to centre off toggle switch is ideal, it can be a quite cost effective means of switching points, especially when used on a mimic control panel- but watch out for any that may stick over one way and not return to the centre off position, as these will cause the CDU to remain discharged and prevent all other point operation requests occurring until the failed switch is restored back to its central off position, but the use of the CDU prevents coil burn out motor failure.
The wire used to connect the power supply to the CDU, then the CDU to the point switches and on to the motor coils and of course the return wire needs careful consideration, as to its overall length of wire run and the size of wire to be used. I recommend the minimum wire size to be 16/0.2mm for all connections. Any long wire runs of say over 7 mtrs in one wire then increase the size to 24/0.2mm. Also use 24/0.2mm wire where two or more motors are connected together for simultaneous operation or where a common return wiring system is used. A fact often overlooked is that each solenoid coil has a nominal resistance of around 3.5 to 4.0 OHMS and at 16 volts the current flowing is around 4.0 Amps (V/R). This is a heavy, but instantaneous load on the wiring.
Route setting by use of a diode matrix is another option, but remember that for each diode 0.7v is lost in volt drop! So your input voltage needs to be higher than the normal 16v often used. I prefer to 'route set' on the mimic control panel by actually following a route along its path and setting points as I pass each stud or switch.
The use of Tortoise, Fulgarex or similar slow acting motor is another option and these don't require Probes and Studs, but do need switches that keep the motors power supply on all the time they are moving and normally continuously too once the move is completed i.e. they are Stall motors. No CDU is needed with these types either, they operate directly from a power supply, nominally 12volts dc See 'Stall Motors' below.
Below are shown three of the most simplest forms of electric point controls using a Passing Contact lever such as the Hornby R044 Black lever or the Peco PL26.
Shown below is a very simple track layout plan using Live Frog (Electrofrog) points. In the first drawing the points are all set for straight running or are in the 'Normal' position and three positive and return track feeds are needed. Note the Insulated rail joiners (IRJs) fitted after the frog Vee rails.
In the second lower drawing the points have all been moved to their 'Reverse' positions and now by comparing the two drawings it can be seen how the live frog causes the points rails after the frog to swap polarity.
In the third and right hand drawing, point number 3 has remained Normal while points 1 & 2 have moved Reverse.
If the IRJs where not fitted after the frogs a short circuit would occur where the blue arrows are shown and a red rail meets a black rail.
Electrofrog or live frog points such as the Peco Streamline range prefixed 'SL-E', those manufactured by Tillig, Marcway and many other track manufactures require a little more careful installation, as they will have to have a gap or Insulated Rail Joiners (IRJs) some know these as Insulated Fishplates, fitted after their frog and normally fitted onto the ends of the two Vee rails leading away from the frog. The reason is, as these points move over and back they swap electrical rail polarity on the frog and the two Vee rails if there is no means of stopping the power flowing out of the frog there is a risk of a short circuit occurring as a positive feed meets a negative.
Other than fitting the IRJs onto the frog Vee rails, nothing else needs to be done to allow the live frog point to work. That said, a large amount of live frog point users will opt for some means of electrically switching the frogs polarity and not rely just on the switch rail touching the stock rail for a connection. This is where the polarity of the frog and its two Vee rails up to the IRJs is controlled by a change-over (SPDT) switch, which is often a switch mounted onto the actual point motor. This then removes the sole reliance on the contact between the points moving switch rail and the fixed stock rail thereby improving electrical power feeding through the point. The wiring is shown in more detail in the Live Frog Switch Wiring section on the Electrical Page 2. However a viewing of the Video below may well help understanding how on a Live frog point the frog polarity is swapped over and the need for the two IRJs after the frog.
Above is the latest Peco Code 100 Electrofrog point with the factory
fitted gaps in the two closure rails.
Above is the same Peco Code 100 Electrofrog point underside view and the two closure rail links can be seen. Also note the factory fitted frog polarity wire.
Below is simple little video showing how an Electrofrog (Live frog) point switches the track power between the two routes (Note: This does not occur with insulated frog points). Note that if the two sets of Insulated Rail Joiners after the frog where not used a short circuit would occur every time the points switch blade moves over and swaps the frogs polarity between positive and negative. i.e. The two rails leading away from the frog swap polarity (positive or negative) with each direction.
Insulated frog points, sometimes they are called 'Dead frog or 'Insulfrog'', have as their main advantage the fact that they need no additional work other than fitting them into their correct place on the layout (excluding any form of motorised point operation). All current Hornby, Peco Setrack and Peco Streamline with the prefix 'SL' are all of this type. Their frog area (Frog = the crossing or part of the point where the two closure rails meet and then crossover each other - one directions rail crosses the path of the other directions rail) is made of all plastic, so this small part of the points track is electrically dead all the time. Electrical track power is switched by the position of the switch rail touching against the fixed stock rail, track power to the selected direction or route is then fed via the switch rail onto the closure rail then in fine factory fitted wires underneath the plastic frog where finally they connect to the appropriate Vee rail after the frog. Two such wires are factory fitted underneath the frog, one for each direction. Track power is automatically cut off to the unselected direction, it is of course restored when the point is moved over and set for that direction, then the former route or direction is cut off track power wise. This is shown in drawing 1, "Insulated Point Switching" above. Therefore using insulated frog points is the easiest of all. Their only down side is that they can at times cause poor running especially when a 0-4-0 or 0-6-0 wheeled loco is travelling slowly across these points and the loco will hesitate or even stall completely due to the loss of rail to wheel connection on the insulated plastic frog.
Insulated Frog point problems and cures.....
1) Insulated frogs, while providing the simplest of layout wiring, can lead to poor running as the locos pass over the frog. This often results in stuttering or a complete stall due to the locos wheels loosing electrical power while on the frog. If slow speed running is a key requirement (such as when shunting in sidings etc) I would recommend replacing insulated frog point/s with live frog (Electrofrog) versions.
2) Short circuits caused by the metal wheels touching both rails at the frog. This is much more common on DCC fed layouts as both rails are permanently powered. This can cause the main control unit to detect the short and trip out. The problem of shorting is easily overcome by fitting two insulated rail joiners after the frog and for DCC layouts running in two linking wires from the two rails after the joiners and connecting them to there respective outer rails as shown in the diagram below. For DC layouts new feeds will be needed after the insulated joiners from the control panel and possibly via section switches.....
3) On DCC layouts, even if short circuits are not a problem, after the frog on any insulated frog point you should still install the two linking wires as mentioned in 2) above. These will ensure all tracks leading away from the point are then live and DCC loco's etc can then be shunted on a siding which has a point set against it, or smoke units, and any onboard lighting will remain on if wished. Alternatively, after the IRJs connect both Vee rails back to the DCC bus.
Above is a typical Peco code 100 insulated (Insulfrog) point.
Note the insulating plastic frog or crossing area.
Above is a Peco code 100 live frog (Electrofrog) point.
Note here the frog or crossing is made of all metal rail
Live or Dead?
There are basically two types of model railway points. Live Frog often called Electrofrog (a Peco name) and all insulated frog this type often called Insulfrog (also a Peco name) or Dead frog.
Below are four basic examples of how an Insulated Frog (Insulfrog) and Live Frog (Electrofrog) point switch the track power dependant upon the point blades position.
One other cheap common connector is the use of a piece of Tag Strip board. Here a copper wire ideally stripped from former mains solid wire is soldered to the tag strips two inner facing tags and the outer same tags are used as the feed in and if required a feed out connection. Onto the bare wire are wrapped and soldered the sub circuit wires.
The picture above shows the main feed or 'Bus' wire with four sub circuit wires attached and soldered and is pending being insulated with some PVC tape
The next easy method of use and no soldering is involved is to use a 12 way strip of terminal block connector or cut a 12 way strip cut up into the required outlets needed, but always allow some extra for future alterations!
Below shows a simple example of the Terminal Block idea where a 12 way strip is divided into 2 x 6 ways.
In Photo 13 a SPDT (Single Pole Double Throw) toggle switch or On-Ontype is shown. Photo 14 is a DPDT (Double Pole Double Throw) toggle switch On-On for 2 separate circuits while Photo 15 shows a 4P3Way (Four Pole Three Way) Rotary switch while Photo 16 is a Hornby SPDT On-On lever switch.
In both Photo's 13 & 14 the central tags are the armature (moving contact or common connection). The output tag (making contact with the common) is normally always opposite to the direction of the toggles lever. Hence - toggle lever to left the right and centre tags make contact, lever to the right the left and centre tags make contact. If the switch has a centre off position then neither of the outer tags make contact with the central tag while the toggle lever is centred.
In Photo 15 rotary switch, the four central tags are the four 'Ways' of the switch and the outer tags make the connection to the appropriate way. Photo 16 is a Hornby On-On lever switch (SPDT). i.e. This does the same function as the switch in Photo 13 .
Consideration must always be given to the feed (Bus) wires size so as it can easily handle the larger current flows and any long wire runs where volt drop occurring in the feed wire may cause issues. Circuit protection should be considered too. This can be via a in-line fuse inserted into the positive feed after the Power supply or a self resetting circuit breaker both being of the correct current rating to protect the wiring and the power supply.
The simplest of these distribution connections can be a feed (Bus) wire that has had a small portion of its insulation stripped away and the sub circuit wires are then wrapped around the stripped feed wire and ideally the joint soldered. The joint once cooled is then covered with Insulating tape. This initial joint pre insulating is shown below.
'Poles' are the number of independent electrical parts within one switches body.
So a switch can have one or more poles. e.g. 'SP' means Single Pole - One electrical input. 'DP' is Double pole - two independent and isolated electrical parts within the switch. 'TP' is therefore Triple Pole or three independent and isolated parts within a switches body.
'Ways' are the number of electrical paths or outlets a switch has. So a 1 way is just a single on / off function connecting the input (Common) tag to the output tag or disconnecting the output tag when the lever is in the opposite position. So a 3 way switch would have three separate outputs from one common input i.e. the switch can be turned to any of three positions and each position connects that outlet with the common input terminal.
‘Throw’ is the number of electrical outlets connected to the common tag. A Single throw switch (ST) will only provide On / Off switching therefore the switch would only have two connection tags. While a Double Throw (DT) will make contact to either side of the switch dependant upon the toggle or levers position. i.e a DT switch will provide On - On to the common tag. It will have three terminals or tags and is sometimes called a "Two way switch" (Just to confuse matters!).
In all cases I use the term C/O as meaning 'Centre Off' when referring to switches.
Rotary switches offer many contacts and normally several positions or clicks of the rotary shaft (or knob when fitted). Typically these can be 4 pole 3 way to 1 pole 12 way, Now don't get confused here, 'Ways' are the number of positions a rotary switch can be turned to. So for example a 3 way rotary switch can be turned to any of three positions. While the 12 way can turn to any of 12 positions. So for example a 12 way 1 pole rotary switch can click or turn to 12 positions, but it only has one input (way) which is then connected to any of the 12 output positions selected. While a 4 pole 3 way can turn to any of 3 positions and it has 4 inputs (poles) that can give any of three outputs each! To confuse even a little more rotary switch can be supplied in ' Make before Break' or ' Break before Make' configurations! Mainly for model railway use the Break before Make style is the one needed, as we need to ensure the circuit being switched is disconnected before the next circuit is connected.
While the above drawing shows the two feed connections onto the rails almost at the joiners location in reality these feeds can be anywhere on the lengths of rail going away from the joiner.
Once all the track feeds are run in proceed onto running in the point motor feed wires. But firstly stop and have a well earned cuppa!
SWITCHES..… Various styles of switches can be used in model railway electrical controls but perhaps the most common switch to be found is the Toggle Switch often the smaller "Miniature" style. The rotary switch is also popular as this allows many switching contacts to make or break with the turn of a central shaft.
The Toggle switch is readily available in various contact formats and lever positions i.e. On-Off, On-On, On-Off-On or On-Off-On centre off spring loaded to centre off or even some that are biased to one position.
Below I have listed some various type of Toggle switch contact arrangements normally found....
Click on a picture to view it larger.
Above - Photo 4 shows the underside of a piece of Peco Code 100 track. Photo 5 shows the sleeper joining webbing being cut and removed. Photo 6 shows the rails undersides have been solder tinned and the two dropper wires insulation stripped and the wires tinned. Photo 7 shows the two dropper wires soldered to the rails undersides. Photo 8 shows the baseboard marked where the track centres are to be. Photo 9a 4mm dia hole is drilled in the centre line. Photo 10 The two dropper feed wires have been passed through the hole and the track laid into its final position. Photo 11 shows the ballast has been spooned (Teaspoon used as a mini shovel) over the track pending final brushing into place. Photo 12 shows the final track laid into position, ballasted and ready for a coating of bonding adhesive. Dilute PVA with water 30/70 and a couple of drops of washing up liquid or Meths to the mix to remove surface tension, then applied carefully with an old eye dropper or larger Pipette and allowed to dry untouched for at least 24 hours.
Carry on running in track wires until are all installed. This may (and will no doubt) include “through feeds” not actually connecting to any sections of track on that particular baseboard or area. Remember to keep recording each wire in the diagram book.
I don't recommend using rail joiners (fishplates) as a place for soldering electrical rail feeds onto. The reason is that the two abutting rails will be continually moving a little inside the joiner allowing expansion and contraction of the rails that are leading away from the joiner. This movement will ultimately introduce a high resistance 'HR' into the joint on one or both sides of the joiner. This is caused by the small movement loosening the joiner and dust particles etc in the air combining and making an almost invisible insulation between the two surfaces. Even paint, if the rails are painted with a rust coloured paint, can get inside the joiner and form a HR joint! This insulation prevents or restricts the flow of current from the joiner to the rail/s. The HR rail joiner often manifests itself in loco's running erratically or stopping for no apparent reason on a certain piece of track. So its far better to solder feed wires onto the rails themselves, even if this means installing several wires series connected (daisy chain fashion) along the lengths of track being feed by that supply. Linking or bonding out the joiners is another option by using small sized flexible wires soldered onto the outside of the rail web and running from rail to rail across the joint.
The sketch below shows the problem and option mentioned above.
Using dropper wires made from solid wire and then either soldering or using a terminal connector block offer the layout builder a place where below baseboard electrical testing can be carried out if ever a fault develops. However, if you wish to run the flexible track feed wires directly to the rail, then for side of rail fixing strip approximately 10mm of insulation off from the wire end, twist the strands up tightly together and then tin with solder. Bend the bare tinned wire to approx. 90 degrees to form an 'L' shape some 4 to 5mm up from the insulation and then trim off the remaining tinned end of the wire to just leave some 2 mm after the bend. You should have an 'L' shaped solder tinned piece of wire, which will now be soldered onto the rails out surface in the web of the rail. If the track is not yet laid solder the dropper feed wires to the rails underside. I do not recommend having more than one wire at this connection on the actual rail, as the wire will become too physically large and will be readily visible and may even cause running problems if it protrudes above the rails top where side of rail connections are used. If you need to have two or more connections then use either a solid wire dropper as above or a short length of flexible wire and connect both (or more) feed wires onto the dropper just below baseboard.
Below shows a complete sequence in dropper wire soldering (underside of rails) and the track being laid and then ballasted. Photos 4 to 12
Above in Photo 1 'D' connectors are used across boards. Photo 2 shows a wiring loom and suitable holes drilled into baseboard frame. Photo 3 shows a simple common return bus bar connection point made from a two way terminal block and a piece of bare copper wire. The right-hand side has the main common return wiring entering and leaving (top and bottom) and onto the loop of copper wire on the left are soldered all the 'local' common returns - mainly here from point motors.
Track feeds are connected to either the appropriate dropper wire which has been passed down through a predrilled hole in the boards’ surface and then soldered to the rails outer web. Or the feed dropper wires are soldered directly onto the rail's underside, if the track is not yet laid, then the dropper wire can be passed through the baseboard via a pre drilled hole, thus making them virtually invisible. For Droppers - the track feed wiring is stripped back approx 15mm and if there is a second wire going onto elsewhere, then that to is stripped and twisted onto the first. The wire/s are then twisted one and half turns onto the dropper wire. This leaves a little excess wire protruding. Push the wire/s up the dropper until they are about 1mm from the board’s underside. Solder the joint and once cooled, cut off the surplus dropper wire and any flexible wire not soldered to the dropper. I like to write onto the board’s underside that particular feeds unique number for future reference. If you prefer not to solder! Then you can use a single terminal block which is attached to the solid dropper wire and the incoming track feed wire(s) are inserted into the lower section of the terminal block. Once both grub screws are securely tightened a good connection should be made.
The first drawing below shows that the solid dropper wire has been soldered onto rails outer web and the track feed wire(s) are soldered onto the dropper below baseboard. In the second right hand drawing a similar feeding arrangement exists but this time the dropper wire has been soldered directly to the rails underside and a terminal strip block is used to connect the track feed. %The final picture shopws the dropper wire soldered directly to the rails outer web or underside.
How to wire….. I recommend drilling 15 or 20mm diameter holes roughly just above the centre line on the underside of the baseboards surface in all directions in cross bracing timbers. These holes are drilled into all the cross bracing ideally before the baseboard top is added. These 18/20mm dia holes will allow ample wire running access and easy wire installation plus it keeps the wiring out of the way. I use ‘zip’ cable ties to bunch the wiring into looms and this makes for a very neat wiring loom. For all common return paths I recommend using suitably sized wire (as mentioned above) in a black colour, run this in first, then follow this with all the track feeds (in a red wire is my choice), mark them onto the wiring diagram as they are run in and terminated.
I like the solder tag strip for terminating wiring onto at each boards end. (Nothing like a nice strong soldered joint!) I personally dislike, but have to use through sheer economics, the so called “Chocolate” terminal strips (12 way plastic covered terminal blocks with two grub screws per termination). Unfortunately, these have a tendency, when the grub screw is tightened down, to cause the wire end to break due to the tension and twisting motion placed onto the stripped wire end. There are some blocks that have a flexible metal strip directly under the grub screw and this is what presses down onto the wire. This type is fine but they are very hard to find, if not impossible, in most electrical stores.
Roughly in the middle of each board I place a common return bus bar connection. This is nothing more than a piece of tag strip or a two way terminal strip with a length of bare 1.0mm copper house wiring wire across its two terminals. The common return wiring arrives at one terminal, the electrical path is then via the copper wire, and it then leaves again via the opposite terminal to the other end of the layout and finally onto the next board. It’s at this common return bus bar on each board that all that boards returns are connected, by soldering each items return wire onto the central copper wire. The drawing below shows how the main return wire enters and then leaves the central connection place and the 'bar' of copper with all the local wiring returns connected onto it. See also Photo 4 below.
When across baseboard connections are needed on layouts that are dismantled for storage etc (Portable layouts) I recommend the use of Sub 'D' connectors. These are available in multi in ways of nominally 9, 15 & 25 ways, but larger version are available. Using the Male and Female halves of a 'D' connector either as in-line joints or one side permanently mounted on the baseboard or control panel etc allows its mating half to be connected via an umbilical type flexible cable or from single flexible wires made up into a bundle. When two or more 'D' connectors are required to be adjacent then reverse each 'D' connector so as a male plug has a female socket mounted next to it also possibly mark each one with differing coloured tape or paint as this also adds to help prevent incorrect connections. See the in-line connections shown in Photo 1 below.
In the above diagram it can be seen that all the return paths are joined together and ‘connection bus bars’ (Denoted by the solid dots) are arranged along the length of the layouts common return wires route to enable connections to be made from all the tracks, point motors, lighting etc returns. The Power Supply box shown above is only a representation and not meant as any particular power supply unit.
Wire itself… I prefer to use single flexible wire, nominally available in 7/0.2mm2, 16/0.2mm2, 24/02mm2 and 32/02mm2 the last two are often used for common return wiring – which I keep to a black coloured wire sheath. The numbers '7/0.2'mm mean for example:- 7 is number of strands inside the PVC sheath and 0.2mm2 is the actual size of each of these wires in millimetres. So there are seven copper wires each of 0.2mm2 diameter inside the sheathing (16/0.2 has 16 individual wires inside it). The colour of the sheathing matters not, Red, Green, Blue, Yellow etc you can use all one colour or decide to make a specific colour for one function e.g. red for all track feeds and perhaps all point feeds in blue etc. it’s your choice. It may be a little less expensive to buy ten or more rolls of one colour wire than two or three rolls of differing colours. 7/0.2mm can carry nominally 1.4 amps, so it is ideal for some model railway wiring in “N” & “00” gauges, but use it with caution, and keep wires running in this small size short in length especially where any track feeds are concerned. Its larger brother, 16/0.2mm can carry at least 3.0amps and is suited to the larger gauges of railways (“0” or “NG” etc). 16/02mm is also ideal for “N” and “00” gauge point motor wiring between the operating point switch and the actual motor. Use 16/02mm on most point operation wire runs and use even larger sizes of wire on runs that exceed 21 feet (7m) e.g. 24/02mm. For the smaller layout 24/02mm will make a good choice for the common return wiring, where at any one time there might be three or so amps flowing, on larger layouts consider 32/02mm or even 50/02mm wire for the common return if need be. You can of course 'double up' the common return wires (or better still increasing the actual conductor size) as this will give more current flow potential and help overcome any volt drop problems.
I really don’t like the use of solid single strand wire, mostly this is the so called bell wire or ‘Post Office’ style wire (ex telephone wiring). While it will work, it does suffer from low current capability and volt drop problems due to its small conductor size and I find it breaks far too easily and is certainly not suitable for any layout that is portable. So keep with the flexible types!
Soldering.... There is only one way of making a solid electrical connection, as far as I’m concerned. That’s by soldering! People shy away from soldered connections and I can never really understand why? The basics are:- Soldering iron of suitable size for the work being undertaken with a clean bit, Rosin cored solder and clean connections. Lets make a start…. For everyday soldering a 25 watt iron with a small to medium sized bit is all that’s required. Larger bits sizes and bigger wattage irons have their place, but not for most electrical joints. I use two irons in the main. An Antex 25 watt or an Antex 18 watt. Both do the identical jobs, it just that the smaller wattage one has a 1mm dia. tip fitted while the 25 watt one has a 2.5mm bit. The smaller bit is ideal for electronic printed circuit board work.
To make a good quality soldered joint, heat the iron for at least five minutes. Don’t rush, the irons tip must be up to full temperature. Have to hand a damp, soldering iron's tip cleaning sponge pad. If you own a soldering iron stand its likely it came with a sponge. If not, then cut a piece of ordinary sponge and use that. (I’ve used pieces of car wash sponge, but best of all is a cut up kitchen cleaning sponge!) Remember to keep the sponge damp. Once the irons hot, wipe the tip onto the sponge to remove all previous oxidisation and old solder residue. Assuming the tip is in a good condition, apply a little of the rosin cored solder to the tip. On electrical joints never use solid stick type solder or so called ‘tinmans’ or the paste and most liquid types of flux, as these all contain a mild acid which over a long period of time causes high resistance problems within the soldered joint. Solid solders and most liquid fluxes are normally the reserve of the solid sheet metal soldering jobs – Loco building, plumbing etc. There is one exception and that is the use of a special flux specially sold for electrical work -do ensure the flux is of that type. One such example is Carrs Orange label.
With the irons tip coated in liquid solder (wetted) and having previously dry assembled the joint (It must be cleaned too, use a fibre glass brush or scrape the surfaces of both components clean, unless its freshly stripped wire where the sheathing keeps the surface of the wire nice and clean) place the wetted irons tip directly onto the connection. Wait a few seconds for the heat of the tip to transfer into the components and then apply a little more rosin corded solder onto the heated joint, not onto the irons tip. You should see the solder start to melt and flow into and around the joint. Once sufficient solder has been applied to coat the whole joint, remove both the iron and corded solder. NOW DON’T TOUCH or MOVE the joint. Wait at least 10 – 15 seconds after removing the heat to allow the joint to cool and the solder to set. What you should end up with is a solid, clean joint. Sometimes the PVC sheath on the wire/s being soldered will shrink back a little. This is a nuisance at times and is due to a) The wires PVC sheathing having a low temperature range or b) Too much heat applied to the joint for too long a period.
I like using heat shrinkable tubing over any ‘In line’ joints, while it’s a lot more expensive than insulating tape, once shrunk down it gives a joint a more professional and secure finish.
Finally, before you go onto solder another joint or you have finally finished and before you disconnect the iron, clean the tip again on the damp sponge. You will get a many years of use from a soldering iron if you keep its tip clean!
Soldering wires to the bottom or outside of the rail is the same principle, but here I find pre tinning both the end of the wire and the pre cleaned place on the rail where the wire is to connect the best method. Pre clean the rail with the aid of a fibre pen or other means. Tin with a little solder, both the place on the rail and the wires end. Once tinned, I then place the wire end, which has been bent to an small L shape, up to the solder on the rail. Apply a little solder to the irons tip and place the iron on top of the wire and lightly press down towards the rail. The hot solder on the irons tip will cause both the wires solder and the rails solder to melt into one. If necessary apply a little more cored solder onto the wire with the iron still in place should there not be enough on the rail to make a solid connection. Carefully remove the iron and ensure the wire maintains in contact with the rail, waiting for 5 to 10 seconds to allow the soldered joint to cool. The use of a small screw drivers blade or even tweezers to hold the wire in place until the solder solidifies and prevent your fingers burning is an option I often use. The use of crocodile clips or any similar sprung clamps fixed onto the rails just either side of the soldering work area are advisable, as these act as mini heat shunts and help prevent the rail being overheated away from the soldering area which can if the heat is allowed to be transmitted along the rail, subsequently causing the plastic sleeper fixings to melt.
Wiring Diagrams.... A simple wiring diagram extract is shown below. Here, and for illustration only, a controllers output wire is feeding three isolating switches and one direct rail feed is shown. As the wires pass around the layout there is a need for terminals and these are shown as circles with dots inside them. On a portable layout there would also be plug & socket pins to be shown. In the illustration one circle equals a connection onto a terminal block. Each item is uniquely labelled to aid future wire tracing/fault finding. 16 wires are shown here in all. Note the switches are drawn open (Isolated).
Now we have a plan which shows all the feeds and returns. It’s time to decide on the type of wiring return arrangements to be used. I opt for a one wire Common Return system. This is where every return path is connected together and then one (or more if need be) return wire(s) go back to the controllers or power supplies output terminals for all supplies - ac and dc. The reason I choose this method is its simplicity of wiring and the reduced number of wires needed to get back to the controllers and power supplies. There are of course other methods of wiring and by no means is Common Return any better than any other. The other simple method is giving each return it own direct wire path – this is hugely wasteful on wiring. Another alternative is to consider splitting returns to say all Track power supplies, all Point power, all Signalling, all Lighting & everything else i.e. up to five return paths. I really can’t see any advantage in this over the conventional one wire common return system. Note; I do not recommend Common return wiring be used for DCC systems. Nor do I recommend common return be used where a mixture of DCC and analogue controls exist. e.g. DCC loco control and points fed via analogue etc.
One thing that must be absolutely certain before common return can be used, is that each power supplies output comes from a totally separate winding on the transformer or has totally separate transformers. One transformers winding feeding two outputs will result in a certain short circuit occurring under the common return system.
Track Plan. Draw on to your track plan the power feeds as open (or coloured) triangular fillets for all the feeds and solid black shade triangles for returns. I usually give each feed a unique sequential reference number. Draw in the isolating section feeds and give these a differing and unique reference number. e.g. Iso 1; Iso 2 etc. I advocate the main track feeds as being marked as 1xx, 2xx or 3xx etc. following on by the next sequential number. So you end up with all the feeds in one direction being 101, 102, 103 and the other line as being 201, 202, 203 etc. Any other feeds become 301, 302 etc. All this may seem a little unusual and strange, but it will become clear later on. See the extract below. Note this also shows several 'Sig Iso' sections with blue triangles, where the track at a particular signal is automatically isolated when that signal is at red, but powered when the signal is at a proceed aspect. All the points are numbered and the "N" denotes the side of the point blade that's closed for Normal running. Note the insulated rail joints are all shown too and in the drawing below live frog (Electrofrog) points are being used, hence the increased amount of insulated joiners needed.
Below I have shown the same track plan, but this time the layout is using live frog (Electrofrog) points, so additional insulated rail joiners (IRJs) and track feeds and returns are needed. Do not be alarmed by the two types of points used in model railways - Insulated or live frog, these are described in much more detail later on in the Points section.
The very simple track plan below uses the above wiring and is a basic loop of track and using Insulfrog points it has three sidings and one platform loop. Note that at the top there is a complete break in both rails made by inserting two insulated rail joiners, this isn't always necessary but does prevent a back feed occurring into the siding point leading off the main line (Always feed into points never back from the frog end). Note that technically the second feed connection bottom right isn't strictly necessary if the top pair of IRJs are omitted, its only there to improve electrical conductivity. All sidings only have power to their rails when the point is switched to that siding. The isolating sections at the end of each siding, when turned off (Isolated), permit loco berthing and they allow another loco to enter the siding as far as the insulated rail break, but not actually passing over the IRJ or beyond it unless the appropriate isolating switch is turned on. One siding has two isolating sections and this allows two or more locos to be stabled. Both platform tracks have isolating sections which when isolated allow locos to be held in that section while the rest of the layout is operated normally. e.g. A second loco could remove the coaches or trucks from the isolated loco and take them into the siding or the other platform etc.
When planning the layout always try to arrange for rail power to feed into a set of points at the tips and out via the frog end. This will ensure power is routed in the direction set by the point.
A simple example is shown below.
Wiring. I cannot stress most importantly the usefulness of a wiring diagram book on any layout that has more than just a basic track configuration. Each wire and termination place is drawn and then easily found should at anytime in the future there be a fault or need to alter something. Make it simple to understand and above all show each wire as a simple single line on the diagram - See the example below.
Below can be seen the wiring diagram for a basic controller feeding one track or loop etc. It has several feeds taken directly to various sections of the track it controls to allow improved electrical performance around the track. In addition and taken off of the main feed is another wire that passes onto Isolating switches (On/Off switches) which improves the final operation of the railway by providing sections of track that can be switched off (isolated) and the remainder left powered. i.e. ends of sidings or in platforms where a loco may be held while another is running etc. The isolating sections should have plastic rail joiners fitted to one rail where the isolating section is at the end of a siding, or two joiners spaced a suitable distance apart to provide a section of rail that can be isolated, such as in a platform where the isolating sections length will be the longest locos length plus a but more spare for stopping distance inside the section.
AUTO STOP at a sidings end (dc layout only). A useful item for dc operated layouts is the 'end of siding auto stop'. This is nothing more than the normal IRJ (insulated Rail Joiner) fitted into one rail at least the longest loco or multiple units overall length plus about 50mm back from the buffer stop, it can be longer if wished. Then a diode is connected across the IRJ. The loco is driven into the siding as normal and when all its pick-up wheels (those wheels that pick up electrical track power) are beyond the IRJ, the loco automatically stops as the diode is blocking the positive inward direction current flow. By reversing the controller and this automatically reverses rail polarity feeding, the loco can be driven out as normal. If wished, a non locking push to make style push button can be wired across the diode, so as when the loco enters the auto stop section pressing the push button allows the loco to run further into the section. Releasing the button will stop the loco once its beyond the IRJ. In the circuit below it is assumed that the lower (right-hand when facing forward) rail is at a positive polarity when the loco is being driven into the section. When rail polarity is reversed the upper rail become positive and the insulation gap is bridged by the diode allowing the negative current to flow through it, thereby allowing the loco to leave the section. If the loco doesn't automatically stop when all its wheels have passed over the IRJ then reverse the diode.
Where a fan of sidings independent of the main line two controllers are used and a selection switch allows the operator to select which controller powers the sidings. This then allows shunting within the sidings area with the main line entrance point set against the siding and the main line running separately. Also it may be very desirable to hold locos at the ends of sidings while still being able to operate the rest of the sidings. In the very simple two drawings below the track layout is shown in the upper drawing with the isolated joiners fitted. Note the pair of joiners needed at the siding entrance from the main line and the two electrical track feeds and three isolating section feeds at the sidings ends.
In the lower drawing the actual wiring needed to accomplish this is shown. One Single Pole Double Throw (SPDT) toggle switch is used to select which controller is to power the sidings or it can be a Hornby R046 yellow lever, but this would not provide centre off. Three isolating switches provide track power selection to the siding end portions. These are Single Pole Single Throw (SPST) toggle switches they can be Hornby R047 green lever switches etc.
Note; that the two controllers must be fed from separate power supplies or transformers and the controllers outputs are linked on one output terminal as shown.
So, now in our simple track design we can add another isolating section of track, possibly in a station area. Only one such section has been shown below for clarity, but many sections can be included. Each controlled by an On/Off switch and fed from the appropriate controllers output. Note on a loop of track two IRJs are need - one at the start of the isolating section and one at the far end of the section.
The picture below shows a Peco insulted rail joiner (nearest rail) and a metal rail joiner. Note the insulated joiner is manufactured from a Nylon type material and has a small end stop or end post to prevent the two rails touching end to end.
In the above drawing an insulated rail joiner (IRJ) has been used in one rail of the siding to enable electrical isolation from the rest of the siding and any other track areas. The On/Off or Isolating switch provides track power as and when required to the Isolating section of track beyond the insulated joint towards the buffer stops. When using Insulated frog points the whole siding will only be live electrically when the sidings entrance point is moved over to the route leading into the siding and the end isolated sections on/off switch is turned on. An alternative is to take the sections feed directly from the controllers terminal that also connects to the same handed rail elsewhere and this is shown in the simple layout design below. Any number of IRJs and associated switches can be used and two or three sections of a siding or main line (in a station platform areas for example) can be switched on /off as required by their respective isolating switches, thereby giving much more controllability to the railway.
A simple example below shows three isolating sections wired back to the main controller. Then each section is switched 'On' as needed to allow a loco to proceed from the main line towards the buffer stops on the right. Each 'Section' has to be longer than the longest loco to be held. The proceeding loco can be held electrically isolated in any section. and another loco run into a clear preceding section if wished. Three isolated sections are shown in the example, but there could be just one section or many more than the three shown, depending on the length of the track.
Isolating Sections. On the railway there will needed sections of track that can be separately isolated to allow the storage (stabling) of locos while the rest of the railway can be operated normally. This is done by inserting an Insulated Rail Joint (IRJ) in one rail. Then the track beyond the IRJ is fed via a simple On/Off switch. By turning the switch Off the section beyond the IRJ is isolated or cut off from the track power, when the switch is On (Switch contact closed) then that track section is powered as normal.
Now the layout has a second cross-over pair of points and a siding added, plus a switch to isolate the end of the siding. Adding far more operating interest.
Note: As an aid to help me depict the tracks in a drawing, they are now shown as being in different colours or just one or two colours.
Always try to arrange track power to flow into a point from the points single (Tip) end then its switched by the actual points position. This simple example shows a section of a twin tracked railway with two controllers each feeding their own tracks. Note the two Insulated rail joiners (IRJs) replacing the metal joiners in the cross-over rails these keep Track 1 controller electrically separate from Track 2 controller.
Below is the same two loops of track as shown in the previous drawing but now with a cross-over point added. Note the use of a pair of Insulated Rail Joiners (IRJs) to electrically separate the two loops / controllers. To pass track to track both controllers are set to the same direction of travel and roughly the same speed. The loco travels from one controller to the other as it passes over the cross-over and the IRJs. Then the first controller can be turned off and once the train is clear of the cross-over points the points can be put back to their Normal straight ahead position.
In the two very simplistic drawings below it can be seen how the basic train set increases from a single tracked loop to a twin looped layout and a second controller. If you wish to make the loco travel in the opposite direction use the controllers Reversing switch or swap around the two wires at the controller end connection or at the rail connection end, but not both!
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Electrical Page 1
Here I will help with wiring a layout
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