In the above diagram it can be seen that all the return paths are join together and ‘local connection bus bar points’ (Denoted by the solid dots) are arranged along the length of the layouts common return route to enable soldered connections from the track, points etc. Note also that the Power Supplies box above is only a representation, in reality there would be two controllers connected to the outputs from the top two  transformers and perhaps a bridge rectifier too on one supply (Lighting Feed for example) giving a uncontrolled dc output.

Wire itself… I prefer to use a flexible wire, nominally 7/0.2mm² or 16/0.2mm².  24/02mm² or 32/02mm² is often used for common return wiring – which I keep to a black coloured wire sheath. The numbers mean for example:- 7 is number of strands inside the PVC sheath and 0.2mm² is the actual size of each of the wires. 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 e.g. red for all track feeds and perhaps all point feeds 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. 7/0.2 can carry nominally 1.4 amps so it is ideal for most model railway wiring in “N” & “00” gauges, while 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 wiring where a distance between the operating point switch and the actual motor is involved. Use 16/02mm on point operation wire runs that are to exceed 8 feet (2.5m) and use even larger sizes of wire on runs that exceed 21 feet (7m) e.g. 24/02mm. For the smaller layout 16/02mm or 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, 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 was 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 is good to reasonable condition, apply a little of the resin cored solder to the tip. Never use solid stick type solder with so called ‘tinmans’ or the paste or 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 liquid fluxes are normally the reserve of the solid sheet metal soldering jobs – Loco building, plumbing etc.  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.

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!

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).

How to wire….. I recommend drilling 18 or 20mm diameter holes roughly just above the centre line taken from down the underside of the baseboards surface. 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 fro 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 P1 below.

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 'local' common bus bar wired across a tag strip connector with local circuits being fed to the particular board.  Photo 4 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 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.

In Photo 5 a SPDT toggle switch (On-On) is shown.  Photo 6 is a DPDT toggle switch (On-On for 2 separate circuits) while Photo 7 shows a 4P3Way Rotary switch

In both Photo's 5 & 6 the central tags are the armature (or moving contact 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 7 the four central tags are the four 'Ways' of the switch and the outer tags make the connection to the appropriate way.  Photo 8 is a Hornby On/On lever switch (SPDT).  i.e. This does the same function as the Photo 5 switch.

Points....Firstly some terminology and basic types ..

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 (a Peco name).

Below are four basic examples of how an Insulated Frog (Insulfrog) and Live Frog (Electrofrog) point switches the track power dependant upon their position.

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The simple little video below shown how an electrofrog (Live frog) point switches the track power between the two routes. Note that if the two sets of Insulated Rail Joiners where not used a short circuit would occur every time the 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.  This does not occur with Insulated frog points.

Point Motor Wiring. Many layouts will use electric point motors –and in my case I use Peco and Seep ones. 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 control panel, but I have since changed to the so called 'One Wire' system (shown below).   One Capacitor Discharge Unit (CDU) is normally used to feed the whole layouts points and this provides that extra pulse of power to move the solenoid motor, these are wired directly across  the 16 to 24 volt point 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 couldn’t be used equally as well. Using a CDU reduces the current drawn from the transformer and also protects the motor/s from any possible continuous powering which leads eventually to motor coil burn out. So, I advocate always investing in a CDU, they actually cost little more than two new motors!

The drawings below show very simple arrangements of one point motor and either a probe and stud or a switch (Passing Contact type or sprung central off) and a CDU all powered from a 230 / 24v or 16v transformer. You will of course need to operate more than one point on a layout and all that happens is more studs or switches, blue wires (2 each per motor) are run in. Touching the relevant stud with the probe allows the CDU to fire a 'one shot' discharge current through the appropriate stud & wiring and onto the motors coil winding or if using switches the closing of the switches contacts fires the circuit. However, only passing contact or sprung loaded centre off switches must be used otherwise the motors coil would receive full power continuously and quickly burn out. When two or more sets of points are need to be operated at once, as is the case in a crossover, then simply wire the next motor onto the firsts, ensuring the electrical path for Normal is correctly orientated and wired on both points and motors.   Most CDUs can operate up to three or four motors simultaneously and those sold as "Heavy Duty" often can throw up to seven motors. Though I wouldn't like to do this, as 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 other methods to operate points electrically than the Stud and Probe or dedicated point 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 throw double pole (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, as all the motor/s operating current has to pass through them. The centrally off sprung toggle switch is fine, but can be quite costly - watch out for any that may stick over one way and not return to the centre, as these will cause the CDU to remain discharged and prevent all other point operation requests until the failed switch is restored to its central off position.  Route setting by use of a diode matrix is another option but remember that each diode losses 0.7v 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. The use of Tortoise or Fulgarex 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 sometimes continuously. So, no CDU needed with these types either, they operate directly from a power supply, nominally 12volts.

Typical Solenoid Point Motor Wiring

The left-hand drawing above shows a very simple Stud & Probe switching method while in the right-hand drawing a dedicated point switch (Centre Off Sprung to centre toggle switch) is 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 to be used (24v is my preferred voltage).  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.

Peco have released 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. The colours of these wires are a little different to the normal point wiring standard, where black is normally the return. On the PL11 the colours are Red operation one way, Black operation the opposite way and Green is the return wire.   Below is show a PL11 wired to a passing contact switch, i.e. Hornby R044 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.

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 470uf 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. 

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.

Fixing Peco Motors (Below baseboard).  This is easily carried out on the underside of the baseboard by using two suitable length and gauge wood screws and two brass style screw cups of the same screw gauge. e.g. use No 6 x 1/2" (3.5 x 15mm) screws.  Firstly, mark in pencil where the tie bar exactly lies, mark centrally to the left and right sides of the bar and also centrally either side of the operating hole in the bar in line with the track, then remove the point. Join the marks to form a cross, where the cross intersects drill a 9 or 10mm diameter hole this is the position where the drive pin needs to enter the tie bar from below when the motor is fitted.  On the motor, bend the fixing tabs down to form a curved "L" shape and then install the motor carefully from underneath. Ensure the drive pin has located into the hole in the tie bar. Hold the motor firmly in place and with the motors drive pin to one side (The same side as the points are laying). Now move the pin over to the opposite position by hand from underneath by using the pin that protrudes from the underside of the motor, ensure the points move over correctly both ways, if not adjust the motors position as needed. If all is ok then mark centrally both fixing centres with the aid of a bradawl or awl. Slip a brass type screw cup onto a suitable wood screw and drive the screw into place to hold the motor firmly to the underside of the baseboard. Recheck that the motor still moves the points both ways, if ok then repeat for the opposite tab. Note the cups outer edges should encompass the motor lugs and by clamping the lug holds the motor secure.  Recheck that the motor still moves the points over correctly now that both screws are in place,  do this again by moving the underside drive pin  from one side to the other by hand.  

See the drawings below for drilling and fixing details.

Marking out & Fixing Details

Assuming Peco style motors are being used, but SEEP and the newer Hornby type and some others fall into the same category. Note some motors don’t offer point position switching options (Point detection).

Having prepared the mounting for the point motor (Solenoid) the next task is to wire it and if necessary install a switch to provide electrical contacts for proving which way the points are laying.

I recommend wiring each motors coil with 7/0.2mm flexible wire, colour of your choice, and then once the wires are fixed in place, normally by soldering, they are taken to a nearby terminal block (Choc block) connector cut into a six way strip if your going to use switch contacts. If not, then a three way strip is ok. It’s from here the connections onto the main wiring takes place.

Firstly, link together two coil terminals on one side of the motor, with a short length of wire, add to one of these coils terminal (It doesn't matter which one) a second longer wire which will go off to the terminal block    Now wire two flexible wires to the two remaining terminals on the opposite side of the motor. These also go off to connect onto the terminal strip too.

At the terminal strip you will now have there wires coming from the point motor. One return and two feeds.  The two feeds will be called ‘Normal’ & ‘Reverse’ from here on.  Strip these three wires and insert them securely into the first three terminals ensuring the grub screw is firmly gripping the stripped wire not the wires insulation.  Normal wire goes into T1, Reverse into T2 and common into terminal T3. As shown below..

Now decide if you wish to fit a motor switch contact? (SEEP PM1 motors have these fitted as standard!). Using the Peco motor and switch block you will need to choose whether you install a single switch or a double contact type. Let’s assume your installing a PL13 single switch type for now. Before you fit the switch block into place its easier to pre wire it. Solder three wires into the three lugs. Note that two connecting lugs are close together and the third is at the opposite end, this is the 'common' connection. The other two terminals only provide a connection with the common when the point switch is in that appropriate position – Normal or Reverse.  Run the three wires back to the terminal strip. Install the Normal contact wire into the first available connection - Position T4, then the Reverse wire into the next - Position T5 and finally the Common into position T6.

How do you determine which is ‘Normal’ or ‘Reverse’?  It’s your choice! Consider ‘Normal’ as the position in which the point blade is closed and it sends a train in the mostly used direction. (Mainly straight ahead, but not always!)  ‘Reverse’ is when the point is set for the opposite direction.

The switch contact block has to be fixed to the underside of the motor. I recommend Superglue for this. Carefully apply a small amount of superglue to the base of the two metal coil supports.  Place the switch contact block squarely onto the motor coil supports and ensure that the drive pin extending from the underside of the motor has entered into the plastic switch hole correctly, then press the switch block firmly onto place. Immediately and by hand, move the point motor over both ways – This is easily done by pushing the small plastic tube that the metal pin has passed into over and back. If all is freely moving and ok, then firmly hold the switch in its position until the glue takes hold. (Normally around 10-15 seconds)  Warning… Ensure that at no time the glue will be able to enter the switches sliding mechanism where the switch mates to the motor or the switch will become glued up and unusable!  Also once the glue grabs the switch you must be quick in checking it works freely and adjust as necessary, leave it to long and you’ll find you won’t be able to move it! This will result in the need to replace both motor and switch! Always test the switches positioning and fit before using the glue by ‘dry fitting’  and checking its operation is free and correct.

Below is shown the Peco PL13 motor operated switch and how its internal contact changes over and provides the switching.

With the motor and its contact block in place the final wiring is connected to the opposite side of the 6 way terminal block. The three wires connecting to the first three terminals are all motor coil operation and the wires from T1 and T2 go back to the control panel, these form the operation wires and a wire from T3 connects to the nearest Common Return location. Then wires on terminals T4, T5 and T6 are used for switching circuits as required. What these wires from the points switch block are used for is a matter of personal choice. I use them for frog polarity switching as I use live frog (Electrofrog) points, but they could be run back to the control panel and used to illuminate indication lamps/LEDs or operate relays for signal and track feeds? 

Frog polarity switching ensures the ultimate electrical contact from the frog onwards and does away with the reliance put upon the switch blade to stock rail contact. If frog switching is used then take one wire from the rail at the beginning of the point to the Normal terminal 4. Another wire from the opposite rail to terminal 5 and finally a wire from terminal 6 to connect the two rails together just after the frog (Only one connection is in reality needed at the frog end, as the electrofrog links both rails together electrically. In the diagram both rails are shown wired (In red), but this is for diagram clarity only.

See the drawing….

For those who may choose to use Seep PM1 motors with built in polarity switching the drawing below is how they are wired into Live Frog points.

Peco Electrofrog Code 100 Streamline Points  can sometimes be traced to be part cause of a short circuit occurring when a loco traverses the points. What happens is that as a loco’s wheel set passes over the beginning of the points especially on the curve of a point the inside of the wheel flange touches the inside of the open switch rail and a short circuit occurs. While ensuring that all wheels are set to the correct back to back measurement is improvement, there is a simple remedy to the whole problem.   The ‘Fix’ can be applied to both points pre laying or to existing already in work points.

Both require similar conversion, but they are tackled slightly differently…

New and not yet laid points…   About half way along the underside of the plastic sleeper webbing four small gaps can be seen in most mouldings (Note: not all points have these so refer to the photos below that show the exact location of the gap needed). Open up or cut a series of new gaps on all four of the plastic sleeper joining webs so as the underside of the rails can be accessed.  Strip two lengths of flexible wire (7/0.2mm) for about 10mm and tin the whole length. Solder this wire to both the switch rail and its adjacent stock rail ensuring that the free end of wire is about six inches or more in length. Repeat for the opposite switch and stock rail.

Turn the point over and using an electric slitting disc cut right through both closure rails on the frog side from where the solder wires are located and in the next convenient open space between sleepers. (Shown in green in the photo) The cut gap should be filled by inserting a small piece of plastikard or similar plastic material into the gap and holding it in place with a drop or two of superglue. Once the glue has set, cut off all surplus plastikard etc with a sharp craft knife ensuring there is no card above or extending either side of the rail, which could derail a trains wheel set  Give the top and inner faces of the two joints and rails a couple of strokes of a flat needle file to smooth the area completely. 

Place the point into position and mark onto the baseboard top the locations where the new wires will drop through the board. Drill a 1.5mm dia. hole and thread the wires though. Once the point is fully in place and the point motor is fitted (with a motor switch) The two wires from the switch/stock rails  are connected to the appropriate motor switches terminals and join on with the two wires from the appropriate rail feeds or DCC bus. Alternatively, where no motor switch is employed, the two wires are solder directly to the running rails on the approach to the point or go directly to the DCC bus.   See the drawing below.

Points that are already laid… About half way along each closure rail and between sleepers (Between the pivot point and the frog) carefully cut right through the closure rails with a disc cutter. Insert an insulator into each slit i.e. Plastikard as per above.  Solder two wires to the outer web of the closure rails on the points tip side of the newly installed insulating gap, but after the pivot. Then drill two 1.5mm holes in the baseboard inline with the closure rails soldered connection and pass the two wires through these holes. Connect the wires to the point motors switch terminals together with the  feeds from the rails or DCC bus  Alternatively they can connect to the same handed rails just before the points if there is no point motor frog switch in use.  Note: There is no need to fit the stock rail to switch rail connections as this connection is made via the lengthened link wires and will connect through from the rear of the point. Where a motor switch is used to switch point frog polarity then a third wire is run from the point motor switches common terminal to one of the two rails that connect back to the live frog, or onto one of the frog rails itself where an insulated rail joiner is immediately at the end of the point.

In the picture 9 a short circuit can occur on Electrofrog points if a loco's wheels touch the open switch rail.   In P10 the Peco Code 100 Electrofrog point has been adapted to ensure the switch blades always carry the same polarity as the stock rail by the insertion of two cuts in the rails (Green) and soldering two wires.  This is shown fully completed in P11 with the new insulated joints and wires installed.  P12 shows the underside of the converted point.

Peco Code 75 points you will find have factory installed insulated joints into both closure rails (green below) and then linked across the insulation on the underside with two wire links. To convert these, cut the two wire links on the frog end of their connection to the rails, leaving the switch blade end still connected.  Now solder two lengths of layout wire onto the ends of the two former link wires and wire as the below drawing. These long wires can go back to the motor switch, or if not fitted, then as the dotted examples of straight to their similar handed stock rail i.e. left link to left rail etc. or if you're using DCC then to the DCC bus  There is no need to link the stock to switch rail if this is too difficult to undertake, as the two lengthened link wires form this connection by connecting to the rails before the point or the DCC bus. All methods are shown here...

The Peco Electrofrog 3 way point..

This item often causes concern and confusion when layout builders try to wire one.    I recommend that you use point motors fitted with at least single pole change over switches (micro switches) or better still double pole switches or micro switches. Where the double switch is used one set of contacts (3 in all) undertakes the track feed switching to the frog(s) while the second set of contacts can be used for controlling signalling or indication of point position on a control panels mimic diagram etc.

Below is show how the two motors of a three way point are connected via a simple diode matrix to three route selection switches and the CDU.

The diagram below will show how the Electrofrog switching needs to be wired for live frog points that have three wires, one wire coming from each frog.

Some 3 way points are supplied with two wires from the frogs. These are wired similarly to the three wire type above, but the yellow frog and wire is removed and the former yellow frog is internally connected to the blue frog as shown and wired below (This technically occurs in the above three wire version anyway, as the two frogs are connected together at the micro switch - yellow and blue are wired together).

DOUBLE SLIP wiring seems to cause problems. Below is the wiring diagram for these points.  Note the motor switching to frog connection is at opposite ends of the slip.

DIAMOND CROSSING.  Below is the wiring for a live frog (Electrofrog) diamond crossing. The use of a  four pole double throw (4PDT) toggle switch is employed to switch the diamond crossings four live frogs. A 4 pole 3 way rotary switch could also be used with the central position being off. The toggle switch is set to the right to run from points 'A' to 'D'  or the the left to run 'B' to 'C'. Normal frog polarity switching is carried out as per usual for live frog points (see above) via point operated switches. The 10 IRJs show are all required to provide isolation.

Mimic Panel Point Indications.

Routes on a control panel or Console can be simply wired by using a controllers uncontrolled 12volt dc output to provide a supply to illuminate point route setting indications. In the circuit below a common 12volt positive dc feed is run around the layout. Onto this is tapped wherever needed a wire to feed off to the point activated switch's 'common' terminal. Two wires are then taken back to the indication panel and feed one or more LEDs as required per route. The points being Normal illuminates the straight route of LED/s and moving the points reverse then illuminates the opposite route or directions LED/s.

To save on wiring, especially where a number of indications are being returned to the panel, a twin 12v dc bus is fed around the layout carrying a 12volt positive and a 12v negative feeds from the controllers uncontrolled output or perhaps from a separate power supply, as shown below. From each point operated motor switch two wires are run to and connected onto each of the 12v bus. From the point motor switch's 'common' terminal there is just one wire per point end going back to the panel (thereby saving one wire per point end over the previous wiring) and this illuminates the appropriate group of LEDs, which in my case 2 x 3mm yellow type. In addition, this twin 12 volt supply bus is used to power other accessories such as signal lamps etc.

Two LEDs are mounted into the mimic panels track diagram per route and both are feed via one resistor per LED.  It is important to note that in this circuit one route direction of LEDs are wired the opposite way from the other routes LEDs.    Where a route is showing a cross over, from say up to down line, then four LEDs illuminate that route i.e. two per point end.

CDUs  These often are purchased as either Standard or heavy Duty types. The 'Standard' version will throw some 2 to 3 point motors simultaneously while the heavy Duty variant will normally throw 6 plus motors at once.

A CDU can be constructed from some basic electronic items and even a version that will throw several motors can be made for a couple of pounds. Shown below are the basic and advanced CDU designs.  Where a heavy duty version is required increase the capacitor to 4700uf or use two 2200uf capacitors in parallel. Note the capacitors should be rated at at least 35v or higher volts.

Now for all the rest of the wiring….

Signals & Lighting....

Series and Parallel.

What is meant by the terms "Series" or "Parallel" connected?

Series connections can simply be likened to that of 'daisy chaining' the items together, this can be any number if items from two up. Series connecting filament lamps together will allow several lamps to be fed from one supply volts where the individual lamps voltage is below that of the supply.  Series connecting resistors together will increase there total resistance, while capacitors connected in series will reduce their overall capacitance value.

Parallel connection can be likened to having two supply rails or bus and each item is connected across the pair of buses or rails. The items being connected on a dc circuit are connected between positive and negative supply paths. Lamps connected in parallel must be rated at the same voltage as the supply is at.  Resistors connected to a circuit in parallel have there total value reduced while capacitors connected in parallel have there total value increased.   A single item can only ever be connected in parallel, as for it to work it must have a feed and return.  Confused?

The drawings below may make these two styles of connections easier to understand?

Often on lighting circuits etc there is a need to reduce the supply volts to enable a bank of lighting to operate safely without having to wire lamps in series. On dc supplies this can be easily obtained by using diodes.  By connecting several diodes in series to themselves the supply volts is reduced or dropped by each diode in turn.  Normal 'Rectifier' diodes will drop 0.7volts each, so by connecting them is series the supply volts can be reduced to that required.  In the example below four diodes are series connected giving a total drop of 2.8 volts. But of course the supply volts can be tapped off at any point after one or more diodes to give a 0.7 volt reduction from the previous. The only thing to ensure is that the diodes used can pass the maximum current needed.  Reference to the suppliers data tables for a particular diode will show exactly the maximum current that type of diode can pass safely.

I run a 12 v d.c. supply around the boards, as I use this for colour light signal aspect illumination – the relays do the switching of aspects. At each place where a connection is required I break into the circuit and feed the appropriate signal relay etc.

I also install a 16 v a.c. feed for all accessories and this supply feeds around the all the boards too, in a similar fashion to both the 12 v d.c. and the Common return path.  I feed all building lighting and any specific local effects (Welding etc) from the 16 volts a.c. supply. I use my own voltage regulators and rectifiers all built on a single small stripboard. See the item later.

Simple diagram showing 12 volt dc and the 16 volt a.c. feeders

Signalling.

In the drawing below, I have shown a simple two aspect colour light signal controlled by a 12v (coil volts) relay with two sets of change over contacts – Double Pole Double Throw (DPDT).

The relays use is two fold. Firstly, it saves on wiring between the control panel switch and the signal – Only one wire is used where two would be needed if direct control were employed. Secondly, it provides multiple switching facilities. So it can both change aspects and operate the track isolating section at that signal. Where relays really win is when a four pole relay is used - 4PDT type. This is where the extra contacts can be used for switching other functions, controlling three or four aspect colour light signals and ensuring aspect sequencing is correct. i.e. In a three aspect sequence - First signal at red (1), next signal back at yellow (2) and the one behind that (3) at green. Where four aspects are used the sequence is - First signal at red (1), next (2) at one yellow (lower yellow aspect lit) next signal (3) at two yellows, fourth signal (4) at green. The diagram below shows all this…...

Here, we now move on to improve the signalling, the use of three or four aspect signals is common. These operate in a specific sequence and this portrayed in this diagram......

 The wiring for a sequential three aspect signal is shown below.

Note that when the panel switch for that signal is turned off no relays are operated (Picked) and the signals red LED illuminates via the green and red relay contacts not picked. Also the signals Isolating section of track is disconnected (Isolated).  Operating the panel switch to the 'on' position causes the red relay to pick. This provides an electrical path to the green relays coil and changes the signals aspect to yellow via the red relay picked and the green relay not picked (dropped) aspect's supply contact path (This assumes there is no feed coming from the next signal ahead - its at red). Power to the signals track isolating section is also restored. When the signal ahead steps up to either a yellow or green it provides a 12 volt supply to this signals green relay and assuming the red relay is still picked, the green relay can also pick. This now changes aspect and lights the green LED via its own relays contact closing.  So, we have a three aspect signal checking the signal ahead for its aspect and also sending a supply to the next signal behind when our signal is at either yellow or green. This is automatic sequencing of aspects with control of the red. Only one wire is used from the control panel per signal, the 12v dc common feed supplies everything else and of course everything returns via our common return circuit. Two relays with four contacts each are used and both ideally should be located directly under where the signal is placed on the base board. Simple eh?   If you’re not electrically minded don’t even think about four aspect signalling, as a third relay is needed at each signal!  Alternatively, consider the use of the Heathcoat Electronics MAS-Sequencer-4 and / or their IRDASC-4’s  details via the Heathcoat link on my home page.

Other scenic effects include welders, flashing beacons, lighthouse illumination and sequentially (running) lights used on a recently made fair ground display on another of my ex club layouts, all add to the layouts realistic atmosphere. All of these I make myself using mainly the faithful NE555 or its bigger brother the dual NE556 timer microchip.

To ensure these electronic modules operate correctly a  regulated and smoothed dc power supply is needed. I use the readily available LM7812 positive voltage regulator to do this work. It needs only a few external components and offers a cheap and reliable regulated supply.

One thing to remember with all voltage regulators is they must have at least 2.0 volts or more input than the output required e.g.  A 12v dc output will need at least 14v dc or higher input.

Below is  a simple regulator this can be either free standing or incorporated into a project such as the Welder as further down this page.

 I enjoy making animated electronic effects and the arc welder is probably the most effective. A super white; ultra bright 3mm LED is the light source and gives a really excellent flash to represent an electric welder being used. When the LED is suitably hidden from view and then powered for a few seconds, the rapidly flashing light catches the viewing public’s eye (Not directly shining into their eye though!) and people cannot it seems wait for the next bout of welding to start again!

The wiring diagram above shows a complete electronic welder.  In practice 16v ac is feed into the two input terminals and this is rectified and passed onto a 12v voltage regulator. This gives the circuit a constant 12v d.c regardless of any variations in the 16v a.c supply (which is often floating around 18v to 20v a.c.) IC-1 is a NE556 dual IC. One half of the chip acts as Astable Oscillator and controls the duration of the time cycle between welding flashes. The other half of the 556 works as a Mono Stable one shot timer and controls the length of the welding flash.  The output from the second half of the 556 (Pin 9) supplies a pulse to the NE555 single chip timer which I configure as a Astable Oscillator, this controls the rate of the welding flash. This is variable via VR3 and is nominally set to a flash rate of around 10 to 20Hz. The welding flash duration is approx. 3 seconds, this restarts after a variable delay of around 7 to 20 seconds – determined by VR-1.  The light source is an expensive high brightness white LED. These have an illumination intensity of around 3.2cd (Maplin part No. N30AT). I have produced numerous ‘Welding Kits’ for myself and friends and they cost me around £13.00 each.

             P13      

LEDs

LEDs (Light Emitting Diode) come in all sorts of sizes and brightness. from tiny 1.0mm to the huge 10mm or bigger versions, they run virtually cold and last for many years and they all work on the same principle.  Apply the correct dc voltage and the LED will light!  It is applying the correct voltage and limiting the current available that often causes so much problem!  In the main, most basic 3mm or 5mm dia. LEDs require around 2.2 volts and some 20 milliamps of current flowing to be at their brightest. There are exceptions, but these figures apply to most normal LEDs. So, how do we run an LED safely from our power supply? Simple, we fit a suitable series resistor in circuit!  One resistor for each lit LED.  To calculate the value of resistor needed there is a quite a simple formula to work this out...  Lets take the power supply as being 12 volts d.c.  The forward