Circuit Diagram

[TerryJC]

Attached is the first draft of the circuit diagram for the Control Circuit.

If there are any comments, please let me know.

As soon as I'm satisfied that there are no errors, I will design the Veroboard to carry the IC, Terminal Blocks / Pins and resistors.

[Geoff]

I have just looked at the documentation all seems OK except for the Hardware Test Circuit Diagram where on the breadboard circuit where all the 100K resistors are connected to pin 7 Blue wire and not to 8,9 and 10.
Geoff

[TerryJC]

If I'm honest, I'd admit that that I'd forgotten that the Test Diagram was one of the pages in the document

Thanks for reviewing it; I'll probably look at starting the build over Christmas

Do you have an answer for my query here viewtopic.php?f=26&t=199#p2937?

[TerryJC]

When I began to kit for this system, I discovered that I had insufficient MOSFET Driver Boards in stock and decided to redesign the circuit to utilise an IRLZ44NPBF MOSFET on the Veroboard instead. This is the type that we eventually retrofitted to the Lighting Circuit because of the vastly improved On-resistance when the device was driven from 3.3 V. I have a stack of these because at one time we were planning to use them in the River System.

Along the way, I spotted some errors and also decided to use three DC/DC Converters to derive the required voltages from a 20 V Laptop supply, instead of a 15 V PSU brick and a separate 12 V brick. We have several 20 V bricks in the Railway Store because Clive donated them some years ago.

I have also updated Pages 2 to 6 in the drawing, so hopefully only minor changes should be needed during the build. Geoff, could you comment on this new version please?

[TerryJC]

This new version of this circuit and build instructions includes provision for adjusting the brightness of the Trackside Lights by the use of a Select-on-Test Resistor, plus some minor changes to the Veroboard layout to accommodate this and improve assembly.

[TerryJC]

This version replaces the Select-on-Test Resistor with a potentiometer and corrects some minor errors.

[TerryJC]

This version reflects all the changes needed to develop the deployment board.