CONTENTS Arc Welder Simulator Aircraft Navigation Beacon Automatic Point Automatic Reverser - To-Fro Capacitor Discharge Unit MkII Capacitor Discharge Unit MkII - modification CDU - discussion CDU MkII - Jim's CDU 1,000u - slim CDU 18,000u - flat version CDU 18,000u - slimline version CDU 18,000u - slimline - AC or DC in CDU Jim's CDU - lots of features CDU - for Kato Point Motor Crossing Lights - Jim's Current overload Detection Flashing Railroad Lights - a simple project Flashing Lights - a simple project Hall Device (Hall Switch) Jim's CDU MkII Jim's Slow Servo JIM's LEDs  - distribution board Kato Point Motor Controller LED Tester Linkage between servo and point Make your own Point Motor using a servo Model Railway Time Multimeter Overload Current Detection Point Motor Driver Power Supply MkII Reed Switch    Reed Switch Resistor colours Reversing A Motor Servo as Point Motor Slow Servo - Jim's Servo Speed - animate things Servo's  - a description and problems Shuttle Signals - 6 Surface Mount Resistors Terminal Block Throttle To-Fro  Automatic reverser Track Tester Track Pick-off (voltage) Traffic Lights - a very simple project Train Throttle Wiring a Point Motor 1,000u CDU - slim 18,000u CDU - flat version 18,000u CDU - slimline version 18,000u CDU - slimline - AC or DC in 4-Way Traffic Lights 6 Signals 27MHz Link 36v Plug Pack

                                         to Index

INTRODUCTION This e-book presents some interesting projects for Model Railways. Talking Electronics has produced two books for Model Railway enthusiasts (book-2 is now out of print). The two books are: Electronics for Model Railways-1 Electronics for Model Railways-2   Since releasing these two books, we have designed lots of extra projects and more are being released all the time. There is a very large group of Model Railway enthusiasts in the world and nearly everyone's layout includes more and more electronic devices, modules and controllers. But a lot of enthusiasts are not electronically attuned and have either not studied electronics or had the fortune to have built electronic projects. That's why many of the projects we have designed recently are available as a kit or already built and tested. Even to put a kit together you have to be able to identify each part and fit it correctly as well as owning a fine tipped soldering iron and knowing how to solder quickly and cleanly to prevent overheating the component. Most Model Railway magazines don't have circuits and projects you can build, mainly because they don't have the back-up of component suppliers, reliable kit suppliers or the staff needed to answer questions on fixing kits that don't work. We have all these features at TALKING ELECTRONICS and everything is backed by emails and service. Most emails from us are very short as we have hundreds of emails to attend to each week but you must reply with one question at a time and eventually your problem will be solved.    Colin Mitchell If you have DCC Digital Command Control on your model railway, or are thinking about using it or starting a layout with this feature, here is a website dedicated to helping you: http://www.dccconcepts.com.au/ Digital Command Control is a standard for a system to operate model railways so that two or more locomotives can be controlled independently on the same section of track. Talking Electronics has a simple DCC controller for two trains on the same track and decoders that convert your DC locos to DCC. But there are more than 3 different manufacturers and each has a different set of "code-signals" to perform a particular operation. The system (coding) we use is the USA: NMRA National Model Railroad Association https://www.nmra.org/sites/default/files/standards/sandrp/pdf/s-9.1_electrical_standards_2006.pdf And the hand-held COMMAND CONTROL, NCE Power CAB, has been used to design all our DCC projects.

NOTE: Many of the projects and circuit and ideas in this eBook are available from Talking Electronics as complete kits, fully assembled, or as components at very low prices. Talking Electronics has sold over 300,000 kits during the past 40 years and about 100,000 have been Model Railway kits. You can now get many of the kits fully assembled and tested for those who have a layout but not a soldiering iron. Many of the projects are so new and different and complex that you will not understand them fully. Email: Colin Mitchell and ask for assistance before buying or doing anything. Here are some wonderful layouts and videos taken from the front and back of the trains on the layouts  . . . .   from MODEL RAILWAY LAYOUTS PLANS.com http://modelrailwaylayoutsplans.com/dave-tidies-up-his-layout/?inf_contact_key=93a9574ff8f6930e95fe40eaba006a971b0a3f0fd3ee5d9b43fb34c6613498d7" Video: https://youtu.be/MnBfqBCWNp4 You must join:   MODEL RAILWAY LAYOUTS PLANS.com because they send a new layout every day with videos. This link show the enormous amount of wiring required for a layout with points and signals. This is the latest: http://modelrailwaylayoutsplans.com/john-shows-us-more-of-his-stunning-layout/?inf_contact_key=d02020000d3e42e28f99cc8a315cea07d18a532c4142cb79caf2b269de1401fa Here are 2 of the latest images: There are 200 more photos of layouts on the website:   MODEL RAILWAY LAYOUTS PLANS.com and by joining them via email you will get an email each day with more wonderful layouts. These layouts show the enthusiasm and skill and interest and dedication and endless amounts of money invested in this hobby. Talking Electronics is only able to help with the electronics side-of-things and you will find most of the layouts in MODEL RAILWAY LAYOUTS PLANS.com have very little in the way of street lighting, billboard signs, crossing lights, boom gates etc because few people know about our range of products.    Now you know, your layout can include more than what you have seen. So, don't think you have "gone too far" until you see all the layouts and spent all your spare money for the next 5 years. Your layout can always be "passed-on" or sold, so nothing is wasted. The biggest electronics hobby is model railways. And the greatest joy is squatting-down and watching a train come "head-on." The first time Edison presented a train like this on the "big screen," women fainted. You will just be over-joyed with the realism it produces.

 

CHAPTER ONE THE POWER SUPPLY Every project needs POWER. Power is ENERGY (actually: Power over a period of TIME is energy) and it comes from a battery or a POWER SUPPLY. We are going to describe a POWER SUPPLY that connects to the mains of your house. A Power Supply provides TWO THINGS. It provide a VOLTAGE and a CURRENT. The voltage can be oscillating "up-and-down" and we call this ALTERNATING VOLTAGE and it is given the letters AC. The letters AC actually mean ALTERNATING CURRENT and the term comes from the very beginning of supplying energy to houses and two rival companies had a war. One company supplied DIRECT VOLTAGE and the other supplied ALTERNATING VOLTAGE. The first was called DC and the second called AC. The voltage at all power points of a house is ALTERNATING and to convert it to DC requires a transformer, a rectifier and a smoothing capacitor called an electrolytic. We will not be concerned with any of these components but the three values we will be covering is: THE VOLTAGE    THE CURRENT and if the output is AC or DC. A POWER SUPPLY plugs into your wall socket and delivers a VOLTAGE, a CURRENT and lets you know if the output is AC or DC. A Power Supply can also be called a Wall Wart, Plug Pack, Adapter or "Converter." A POWER SUPPLY FOR YOUR MODEL RAILWAY You will need at least 2 or 3 different power supplies for your layout. This is because a layout requires at least two different voltages. Normally, these are very expensive, buy we are going to show how to use all sorts of "junk" and "discarded" power supplies from computers, shavers, toothbrushes, toys, printers, faxes, mobile phones, old electric drill chargers and anything you no-longer use, and convert them into a power supply. They will cost you little or nothing and they will work PERFECTLY. But you need to know what you are doing as there are lots of different options. The Li-ion 4-cell power supply we will be describing is equal to $100 power supply (from a model railway supplier) and the $35 Power Supply (we will be describing)  using 5 Li-ion cells can be used as a BENCH POWER SUPPLY for all your testing and is equal to a $100 product. And some of the other power supplies we will be describing will cost you either nothing or just a few dollars. Once you have a power supply, we will describe the next item on your list, a THROTTLE. (This is covered in Chapter 4 - halfway down). This is the module that connected between a power supply and delivers a voltage and current to the track to control the speed of the loco. A typical "Wall Wart" or "Plug Pack" or "Adapter" Power supplies are also called wall warts, plug packs, chargers or adaptors and must be of the type that is SAFE. In other words, you must be able to touch the output wires and the tap in the kitchen and not get killed. This is not a joke. If the adaptor is only designed to be used with a fully plastic item, it may be lacking isolation as you cannot touch any of the wiring. This will only refer to very old devices where a simple capacitor was used to convert the household voltage to a situation where the output was fairly low current. Throw out anything that you are not absolutely sure is safe. Now we have a handful of say 10 different, old, unwanted, useless adaptors. We are going to show how to connect two or three together to produce a voltage suitable for many of our railway projects.   Make 4 piles. The first will have current ratings from 100mA to 500mA. The next will have current ratings from 600mA to 1 amp The third pile will be 1 amp and higher. And the fourth pile is for those adaptors that deliver AC. From these piles you will be able to make a power supply using two adaptors by wiring the outputs IN SERIES. Many of the CDU projects from Talking Electronics need an input of 20v DC to 25v DC.  The current can be as low as 100mA as the electrolytics in the CDU will take up to 1 amp if the the power supply can deliver this current, but if the available current is 100mA, the CDU will simply take longer to charge the electrolytic. So, almost any power supply can be used and it is the voltage that is needed so the electrolytic charges to the maximum. If you have two 12v DC adaptors with a current rating from 100mA to 1 amp, they can be combined together by connecting the output wires IN SERIES. If one adaptor is 100mA and the other 1amp, they can be combined and all that will happen is the output current will be limited to 100mA. You can even connect 3 adaptors in series to get a total voltage of 25v. This is one way to use low-output-voltage adaptors to power the CDU project on your model railway. Some adaptors are only 3v to 4v to 5v and they can all be combined.  USING DC ADAPTORS IN PARALLEL You can also connect adaptors in PARALLEL - DC adapters. This involves connecting the negative output of one to the negative of the other and the two positives together. Ideally, the output voltage of each adaptor should be the same as this will equalise the load-sharing. But many adaptors have a high output voltage that drops as the load is applied. For instance a 12v 500mA adaptor can be as high as 17v on no-load and this voltage will drop to 12v when 500mA is flowing. The other adaptor may be 14v on no-load and 12v when 500mA is flowing. These two adaptors can produce a 12v 1 amp power supply ONLY IF the actual sharing between the two is EQUAL. It is pointless placing a 12v and 5v adaptor in parallel as the 5v adapter will never deliver any current. The two adapter share 50:50 when the output voltage is exactly the same. This will never be the case but no damage will be done as each adapter has a diode on the output that prevent one adapter passing any current to the other. This is a good way to use up the box of old adapters. Here is a typical 18v power supply for a model railway.  This is the ideal supply, but it is expensive and our aim is to show how to produce the same output voltage by using much cheaper items (Plug Packs etc.) 18v Power Supply USING AC ADAPTORS IN PARALLEL You can connect AC adapters in parallel, providing they produce the same output. The only way to check this is to connect them together at one end and flick the other two leads to make them spark. If they produce a large spark, you need to change the leads from one adapter. If you flick the leads and a small spark is created, they do not match perfectly and one or both will get hotter than normal as current will flow through the secondary windings. It is very difficult to make any other tests without using a multimeter. When you connect one end of each together and connect a multimeter (set to low AC voltage) to the other two leads, the meter should NOT SHOW any voltage. This means the output of each adapter is rising and falling at the same time and with the same amplitude.  USING DC ADAPTORS IN SERIES Here are two Plug Packs connected in series: You can connect any TWO or THREE together and the output voltage will be the sum of all the voltages and the current will be determined by the lowest current of the 3 adapters. This is very handy for CAPACITOR DISCHARGE UNITS as they need a voltage of approx 16v to 25v DC to fully charge the capacitors. If you do not have any old Plug Packs, you can buy new ones on eBay for a few dollars. You can buy 1Amp or 2Amp Plug Packs. You will need: 1 x 12v adapter  and 1 x 5v  adapter for a THROTTLE. 2 x 12v 1Amp adapters for a Capacitor Discharge Unit. Total of 4 Plug Packs. Here are some examples: THE BEST ADAPTOR:   The best DC adapter for all the CDU modules is a 24v or 30v supply made from two  12v adaptors in series of three 10v adaptors in series. If the CDU module has an on-board regulator, the 30v supply is the best as it will charge the electros to a maximum of 27v. For all the other CDU modules, you should use two 12v adaptors in series and the electros will charge to about 23v.  note: Sometimes you will use a charger (wall wort) (or two in series) to charge a Capacitor Discharge Unit and the inrush current will be more than 1 amp and one of the chargers will "close-down" and fail to deliver its voltage. The solution is to add a 12 ohm resistor for 12v, 18 ohm for 18v or 24 ohm for 24v that is soldered to the positive lead. This will limit the current to 1 amp on turn-on.  The $2.50 plug Pack above was purchased as 12v @ 1 amp.  It was easily opened-up via a screw and clip, to reveal the PC board shown below. The output voltage is determined by the zener diode at the front of the board. The 12v zener was replaced with 15v and now the output is 15v DC. I would limit the current to 800mA, but a 15v supply can be connected to many of the throttle circuits covered later in this article to give 0v to 12v DC output.  The zener diode is "sitting high" to show the diode in this discussion and also to allow test chips to measure the voltage across it. It was then resoldered close to the board and the cover replaced. This module is LIVE when out of the case, so don't touch anything. The new 15v zener converts this power adapter to 15v output. You can also use a white LED in series with the 12v zener diode to get 15v output. Note the cathode of the zener is connected to the cathode of the LED and the 1k current-limiting resistor is linked with a jumper (it is not used). Thus the 15v output drives the LED (3v drop) and the 12v zener drops 12v. The anode of the zener is connected to 0v. The result is 15v output. 36V !! Some of the CDU projects can be supplied with 30v to 36v DC to fully charge the electrolytic(s). You can make a 36v supply very cheaply by using 24v and 12v plug packs and these are available on eBay for less than $10.00 (for both) including postage.     Simply connect the leads as shown in the following diagram to get 36v. Some of these plug packs have a current detecting overload circuit and "shut-down" if the current is more than 1 amp (even for a millisecond). To prevent this we add a 47 ohm resistor. This "trick" only applies when you are using the plug packs for our CDU modules as the high current is only required for a few seconds and then falls to a very low value and the resistor will not get warm when used for this particular application.   THE ALTERNATIVE TO A WALL WORT Because a Wall Wort producing 13v AC or 27v DC is fairly difficult to obtain (almost impossible) Talking Electronics has produced a number of CDU modules that accept almost any voltage (AC or DC or DCC) from 9v to 15v (either AC or DC) and the on-board voltage generating circuit will produce an output of exactly 27v DC. The latest module to have this feature is JIM's CDU MkII and it has a mini trim pot to adjust the output voltage from 13v to 27v DC to cater for all different types of solenoid points.  This module has on-board push-switches to control the position of the point and each module is designed to be connected to a single point or two or three points that ALL need to be activated AT THE SAME TIME.   You can see the project HERE. This is just one way to get around the problem for the moment, but at some point in your plans to produce a large layout, you will need a POWER SUPPLY. You can spend a lot of money on a POWER SUPPLY but Talking Electronics is always aiming to show the cheapest and best way to get something at the lowest cost. Let's look at what we are talking about: BENCH POWER SUPPLY A Bench Power Supply is the name given to a power supply that looks like the following images: They come in all sorts of arrangements and offer current limiting and output voltages from 0v  to 35v (or higher) at 1 amp to 10 Amp or more. But these cost a lot and you can build a similar "instrument" (a piece of test gear is called an INSTRUMENT) for less and since it will be "out of a case" you will be constantly reminded of how it has been put together. Power Supply MkII 0-12v DC(voltage adjustable)   0-1Amp(current adjustable) Power Supply MkII kit from Talking Electronics for $20.00 plus $7.50 postage.  Click HERE for details. (see the full article HERE) The following project is a 0v to 12v BENCH POWER SUPPLY  with current limiting and has an output of 1 amp. This is sufficient for all types of testing and you can increase the values by referring to the circuit. The whole idea is to create projects at the lowest cost and have them open for viewing so you can remember how they were assembled.       This is the cheapest, safest Power Supply you can get. It will deliver 0-12v at 1amp and you can limit the current to a few milliamp so you will not damage a project you are designing. It has 14v at 5 amp  - called an AUXILIARY OUTPUT  - that connects directly to 4 cells and you need to be careful as the Li-ion cells are capable of delivering up to 50 amps if the wires are shorted. This project is called a BENCH POWER SUPPLY as it is a handy piece of TEST EQUIPMENT that is designed to deliver a controlled voltage for a project you are developing. It is not a continuous power supply as the cells need to be charged (when the indicator LED does not illuminate). The Li-ion cells are available on eBay for a few dollars each and you can buy a single-cell charger for a few dollars. These chargers are microcontroller based and they stop charging when the cell is fully charged. You cannot charge the cells from a "battery charger." You can also get a single-cell charger PCB that connects to your laptop USB socket and it will charge a cell very quickly. But you will only be able to charge one cell at a time. All these things are covered later in the article. POWER SUPPLY MkII Circuit You can use 2 x 470R @ 0.25watt or 1 x 1k @ 0.5watt The new PC board uses 1k (in place of 220R shown above as the current limiting resistor for the white LED) to keep the brightness low to stop blinding you.   PARTS LIST Power Supply MkII $20.00 plus $7.50 postage.  Click HERE for details 4 - 1R      0.25 watt resistors 1 - 4R7 1 - 100R 1 - 220R to be replaced with 1k (the old board shows 220R - new board uses 1k) 2 - 470R (or use 1k @ 0.5watt resistor) 1 - 1k (as shown in circuit above) 1 - 22k 1 - 150k 2 - 500R trim pots 2 - knobs to suit 1 - 3v9 zener 1 - 6v2 zener 1 - 9v zener 1 - BC338 transistor 1 - TIP31 transistor 1 - BD679 transistor 1 - 3mm white LED 4 - 2-screw terminal blocks 2 - heat fins 4 - sets of nuts and bolts and 5 washers 4 - hook-up wire for battery boxes (to replace      the rubbish on the battery boxes) 2 - side-view panel meters and 2 stickers and         foam tape to hold them in position 1 - toggle switch 10cm 0.5mm tinned copper wire for meters 30cm fine solder Backing card and 4 feet and foam tape 1 - Power Supply MkII PC Board Trickle Charger Components are included: 2 - 180R 4 - 3v9 zeners 2 - 9v zeners 3 - 3mm white LEDs Trickle Charger PCB Single-cell charger kit $7.00: 1 - USB voltage/current monitor module 1 - single cell charger PC board 1 - single cell battery box 1 - 1R0  5-watt wire wound resistor These parts are not included in the kit: 5 - 18650 Li-ion cells 1 - 4-cell battery box 1 - single cell battery holder 1 - 4 cell charger 1 - single cell charger or USB charger module and single cell battery box These items can be bought on eBay.   Here is a set of 4 Li-ion cells. Just use the 4 lower cells in a 4-cell carrier. The top cell is just to increase the voltage slightly so the project will produce slightly more than 12v at 1 amp. You can buy Li-ion cells for about $2.50 each on eBay. They have a capacity of about 2 Amp-hour to 3 amp-hour. The 4-cell carrier can be bought on eBay for about $2.50 The following 4-cell charger can be bought on eBay for about $3.50. This will charge the cells at about 70mA to 150mA and it will take about 24 hours to fully charge a depleted set of cells.  The charger below will charge a single cell at about 500mA to 700mA and connects to your USB port on a laptop. You can only charge one cell at a time with this arrangement. The 1 ohm resistor will discharge the cell quickly. The cell voltage must not go below a minimum voltage of 2.8v. You need to place a voltmeter across the resistor while discharging to make sure you do not discharge the cell below its recommended minimum.  The module in the photo charges the cell quite quickly and at 4.2v the cell is charged to 90% (or more) and the circuit turns OFF. You must use a charger that turns OFF when the cell is charged as this type of cell cannot be left charging on a "trickle charger" as the cell will produce internal "whiskers" and it will get damaged. More details of the project shown above can be found HERE.  It describes a 1 amp adjustable POWER SUPPLY that can be used to power your locos or as a BENCH POWER SUPPLY for all your testing.  CURRENT How much current do you need?  That is: how many AMPS do you need? A small loco takes 300mA to 600mA and you need a 1AMP supply to make sure the necessary current can be supplied as the motor will take 800mA to 900mA when starting and accelerating and when hauling a number of coaches. For a DC layout, you will generally only be running one loco at a time and a 1-Amp supply will be sufficient. The current values mentioned above apply when the supply is 12v. If the supply drops to say 10v, the current will be less and if the supply increases to 14v, the current will increase by a considerable amount (when the same motor is connected). It is impossible to state the actual values because the current taken by a motor increases and decreases due to the load and this load is not only the velocity of the train, but the acceleration and inclination of the track and also the rpm of the motor (as it takes more energy to rotate at higher rpm) and lots more current when the motor is "loaded." AC TO DC Before we finish, there is a bit of theory that needs to be understood. We have mentioned the AC voltage and DC voltage on (or for) many of the projects. The two values are a little bit different and you may be wondering why. The technical reason is this: When you deliver 10v AC to a circuit that has diodes and capacitors (electrolytics) that convert the voltage to DC, the output is 40% higher than "10" because the 10v AC is actually 14v at the instant when the voltage is rising to a maximum and the capacitors get charged to this value.  There is a loss of about 1.5v across the diodes in the circuit and the output becomes 12.5v Quite often the manufacturer of the 10v AC transformer will add a few extra turns and the voltage will be 13v AC (under no load).  This is done because the output drops when full current is delivered (because the transformer is very poor quality) and this will ensure the output never goes below 10v AC. It drops from 13v to 10v - under full load. However the 13v AC will produce 18.2v AC minus 1.5v = 16.7v DC when unloaded and if you deliver more than 13v AC, the resulting unloaded voltage may be too high for some of the electronic components - especially IC's. CONCLUSION You need to buy or make 2 POWER SUPPLIES: 15v to 17v  @ 1 amp POWER SUPPLY for a throttle (to drive a loco - suitable for 1 or 2 locos). 24v POWER SUPPLY for a Capacitor Discharge Unit. (less than 100mA needed) Cost will less than $15.00 for up to 4 Plug Packs. (see above for details of the Plug Packs you need to buy. If you build a Bench Power Supply (see Power Supply MkII) you will have an adjustable output voltage (0v to 12v DC) and you will be able to limit the current (from 30mA to 1 amp) so the project you are testing will not be damaged. When you have the 2 Power Supplies, you can decide on the Capacitor Discharge Units and the Throttle module. Under NO circumstances should you build a power supply with soldered wires or bare joints or bare leads going to the mains or any wiring with bare MAINS connections. One day a child may come and play with your equipment and touch exposed wires and get thrown across the room. Always use Plug Packs (Wall Warts) or Power Supplies in a professional case. They are called "double insulated" and that means they do not have an earth lead. It also infers they do not have a metal case and this makes them extremely safe.   CAPACITOR-INPUT POWER SUPPLIES You may find instructions or a circuit on the web for a CAPACITOR-INPUT POWER SUPPLY. This is a power supply with just a single or even 2 capacitors connected to the mains, followed by a bridge and an electrolytic. There is no transformer in this type of power supply and although you think the capacitor separates the mains from the 12v output, IT DOES NOT. It does reduce the voltage of the mains to say 12v DC after the bridge, but if you touch either of the output wires and a water tap or kettle or toaster, you will get a jolt of 240v AC and although the current may be less than 100mA, you only need 15mA to kill you. It's the duration of the electric shock that is finally fatal and if you are under a railway layout and cannot remove your hand fast enough, you will get fried. Another point to remember. This has NEVER been mentioned before. The output of a cap-fed power supply is only 12v when the diode bridge and 12v zener is connected. If any of these wires are cut, the "12v section" becomes 336 volts !! The 12v zener is called the LOAD and when you connect your project to this power supply, the current passing through the zener is now diverted from the zener and to your project. But if the zener "blows up" and then your project "blows up" you will have 336volts on your project. This type of power supply is illegal in many countries and hopefully you will never see one. BUT this comment is to inform you: NOT TO BUILD A CAPACITOR-INPUT POWER SUPPLY.

     to Index

CHAPTER TWO THE POINT Using a motor to control a point This is PART "A"  of our discussion on controlling a point. They are called POINT CONTROLLERS (see PART "B" to control a point containing a solenoid) POINTS - TURNOUTS Talking Electronics makes 8 different modules to assist and change and active the points in your layout (to suit different voltages and different situations). That's why you have to read Part "A" and Part "B" A Point Controller is a "device" or "MOTOR" or "SOLENOID" that changes the point from "ahead" to "Siding." The ACTUATING MECHANISM can be a double-acting solenoid to move the rails from one position to the other. Or it can be done with a motor and gearbox or a micro motor and gearbox or a SERVO or even a LINEAR ACTUATOR. These all come in different sizes and at different costs. That's why there is a number of different projects. This section does not cover the SOLENOID POINT. See Chapter Three to control a SOLENOID POINT with a CAPACITOR DISCHARGE UNIT.  All layouts need a point or lots of points so you can make an impressive layout and have the trains leave and enter the main line and provide shunting yards and loops and interconnecting lines. There are so many choices for a point and so many different expenses that we have simplified everything and created the best control modules on the market at the lowest cost for all the different situations. WHERE DO YOU START? Start by buying the cheapest left or right hand point FOR MANUAL OPERATION. This is the  version we will convert to either remote or automatic operation. This is a MANUAL POINT If you have a solenoid operated point, we will cover it later: This is a point with a solenoid actuator to move the rails. We will cover this later in the article. We will firstly cover a MOTOR to activate the point. CHOICE NUMBER 1: This module converts a manual point into a remotely controlled point. There are a number of modules available and the differences will be cost, size, and fast or slowing changing of the point. The first choice is: POINT CONTROLLER using 3v MOTOR and WORM GEARBOX for $20.50.  Click  Here to order. We connect a motor and worm gearbox as shown in the following image to the actuating lever on the point: Image shows the control rod on the gearbox is bent to fit the push-bar of the point. The movement of the control rod will activate the point. You have to provide some "springyness" to the push-bar so that a train coming in the wrong direction will (from the right) will separate the rails and not be derailed.  The arm (lever) on the output of the gearbox is activated about 90° but will move less than this when restricted by the "throw" of the lever connected to the point. Cut the arm to length and bend it carefully by using a pair of pliers to hold the arm and don't let it move where it is held by the plastic output gear. Mount the motor and gearbox with double-sided tape when adjusting its position and finally use glue to hold it in place. The two 500R pots on the latest PC board (not shown) allow you to adjust the strength of the "throw" of the arm. The following image is the module that controls and limits the motor's operation. It allows the motor to be connected to a 9v to 16v AC or DC supply. The module with motor/gearbox is available from Talking Electronics for $25.00 including postage. You get a micro motor with worm gearbox and module and DPDT push-push switch and the position of the point is shown on the red and green LEDs on the module. The movement of the point is fairly rapid. There are other modules with slow movement. The circuit above uses a 3v micro motor with worm gearbox. The latest PC board has a number of improvements with two 500R pots to adjust the strength of the throw of the arm.     oooooooooooooo0000000000000000000000000000ooooooooooooooooo CHOICE NUMBER 2: In place of the micro motor and worm gearbox shown above, you can use a converted servo, as shown in the following image. The servo is converted to a MOTOR and GEARBOX. This module is called POINT CONTROLLER using converted SERVO  for $19.00 plus $6.50 postage.  Click  Here to order. The activating module comes with a push-push switch and knob, that clicks when pushed and unclicks when pushed again. The module limits the output arm of the servo to less than 45 degrees and the position of the point is shown on the red and green LEDs. A length of gold wire is included for the linkage. The movement of the point is fairly rapid. There are other modules with slow movement.   oooooooooooooo0000000000000000000000000000ooooooooooooooooo CHOICE NUMBER 3: This module is identical to Choice Number 2, but this has two mini trim pots to adjust the amount of travel of the arm on the servo.. This choice is: POINT CONTROLLER using converted SERVO ver 4 for $21.50.  Click  Here to order. The Printed Circuit Board has 2 x 500R mini trim pots to adjust the amount of travel of the output arm.           oooooooooooooo0000000000000000000000000000ooooooooooooooooo CHOICE NUMBER 4: This module is called POINT CONTROLLER using 555 IC  for $18.00 plus $6.50 postage.  Click  Here to order. The on-board toggle switch changes the point via a servo fairly slowly and this is the main difference from the other modules.  The servo and gold-wire linkage are included with the module. The module outputs a PWM signal to the servo to provide a limit-to-rotation in both directions and this is adjustable on the new version via mini trim pot (not shown on photo). The on-board LEDs show the position of the point.       oooooooooooooo0000000000000000000000000000ooooooooooooooooo CHOICE NUMBER 5: This module is called POINT CONTROLLER using 555 IC with mini trim pots Ver4 for $20.00. (plus postage $6.50).   Click  Here to order.   Click  Here to order. This is the latest version with mini trim pots to adjust the end positions of the converted servo. oooooooooooooo0000000000000000000000000000oooooooooooooooo CHOICE NUMBER 6: If you want the servo to move slowly to produce a realistic effect, we have a module called JIM's SLOW SERVO for $xx0.00 including module, servos and  extension lead. Click  Here to order.  This module allows the servo to move very slowly. (PC Boards are currently being produced)     oooooooooooooo0000000000000000000000000000oooooooooooooooo CHOICE NUMBER 7: If your layout has a number of points that need controlling, we have a 5 SERVO Controller module that controls 5 servo's separately with very slow action. This module is called 5 POINT CONTROLLER  for $45.00 including module with microcontroller, 5 servos and 5 extension leads. The servos provided with this module are the small 9g version as these servos are guaranteed to work very very slowly from a particular manufacturer. The servos are $2.50 each and the extension leads for the servos are $1.50 each. You can also get aluminium brackets to hold the servo under your layout for $2.50 each.  The 5 POINT CONTROLLER  costs $20.00 if you have your own servos, but remember we test all modules with the very small servos before posting, to make sure they all respond to the PWM signals. The new module uses a PIC16F628 microcontroller as it has more input/output lines and the on-board LEDs show the position of each point.  Click  Here to order.   The on-board tactile buttons need to be pressed for about 1/2 second for the program to recognise the button and activate the servo to set the point to the correct position. You need to set each point so that the PC board reflects the correct position of the point. Do this will all 5 points and you are ready to drive the loco. oooooooooooooo0000000000000000000000000000oooooooooooooooo SUMMARY A manual point costs between $15.00 and $25.00. (you can buy these from any model railway shop) The modules above cater for all sorts of different requirements (such as speed of activation, cost, 1 or 5 points) and this means a remotely activated point can be added to your layout for as little as $40.00 But there are other options, so keep reading. And there are a number of options for a point that has SOLENOID OPERATION - and this is covered next.

     to Index

15-7-2019  Colin Mitchell   

You can copy and use anything for your own personal use.
Direct copying to other websites is not allowed as these projects are updated and too many 
websites have copied my eBooks and not given any credit to me. But you can see they are my projects,
because no-one, except me, has them as a kit or fully assembled.