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Model RR - Solid State Circuits that Work
These circuits schematics shown here cannot be sold.   I did not create them, but I have built them for my own use.  You can use them as well. I sell kits of parts to support them.  While they work well for me, I do not accept any responsibility for their failure or injury or damages they may cause.
Power Supplies
Capacitor Discharge Unit for Switch Machine Control
Schematic with parts list.
Document, page 1.
Document, page 2.
My layout of a circuit board for four units using Radio Shack PC board with bus strips.
Finished circuit board of two CD units, which is half of the previous circuit board layout as shown.
I have tried many different CD circuits and none proved reliable.  I finally located this circuit on the web.  It is used by some model RR clubs and has proven reliable -no melt downs, blown caps, or overheated transistors.  
To play slide show, click on the 1st picture.
Crossing Flashers using IR Sensors
To play slide show, click on the 1st picture.
Completed circuit boards with labels.  Note the relay output for controlling a crossing bell.
Schematic of circuit.
Placement of track sensors for a single track.
Placement of track sensors for 2 tracks or a siding.
Documentation of how it works.
Diagram showing connections.
Diagram showing external connections.
Schematic to drive high current lamps.
Finished double track boards with labels.
Diagram of connections for double track boards.
Arc Welder Simulator
To play slide show, click on the 1st picture.
To play slide show, click on the 1st picture.
Arc Welder Simulator circuit schematic. It includes a modified power regulator which allows it to be conned to a DC supply buss of  12V or greater.
Description of how this circuit works.
PBC layout that I used for my circuits.  Pay careful attention to the transistor pinout.
These parts are available on Ebay and other sources.  I but most of my parts from sources in China that ship via ePacket.
The completed circuit board without the white LED attached.  Attention should be given to the placement of the LED in the scene to hide it from direct view.
Flickering Firelight Simulator
This circuit uses a bulb, which I think produces a more realistic effect than a LED.
Description of how circuit works.
Application Notes
I designed this layout for a PCB to hold 2 modules.  The oscillator on the right uses a .22uF capacitor and the circuit on the left uses a .15uF cap to change the rate of oscillation.  The combination of the 2 bulbs yields an even more realistic effect.
For the ultimate in realism, use dual circuits and two bulbs.   I use white bulbs and paint yellow, orange and red strips using transparent paints.  This throws multi colors at random.
More Circuits:
Using 16VAC Bus Line Power
To play slide show, click on the 1st picture.
Schematic showing how power supplies are used with 16VAC buss line.  It is the schematic for the components of the power supplies as well.
Layout design showing the placement of power supply components on PCB.
Parts lists for components used in each power supply. The choice of voltage regulator determines the DC output voltage.
Picture of a finished 5V power supply.  I typically use this voltage for LED building lights.
Component layout for a 12V power supply.  The only difference is the choice of voltage regulator.
Picture of completed 12V power supply.  The components are reversed in order to use the other half of the circuit board.
Component layout of a 9V power supply.  I typically use these for sound modules and video cameras.
After my 1st layout experience, I decided to use a 16VAC buss line to provide the power distribution to all layout accessories, such as building lights, sound modules, video, and all other electronic circuits.  Using an AC buss instead of DC, enabled me to use a mix of incandescence bulbs and LEDs.   Also, 16volt buss would supply the range I needed from 5Vdc to 12Vdc outputs.
Typical stand-alone power supply.  I use a 16VAC power buss to power most layout accessories (see below).  Other voltages can be obtained by changing the voltage regulator for the required output. 
Need Circuit Boards?
Sick and tired of finding Radio Shack out of stock?  I found some of the exact or better Prototype Boards at Handmade Electronics, www.hndme.com/productcart/pc/
​They are less expensive too.
Universal Power Supply
Using a LM78xx Voltage
This power supply can be used with an AC buss line or as a stand-alone