5/10/17 Custom Circuit Cards

Here are the three circuit cards I had made.
Express PCB has special prices for boards that conform to their 3.8 x 2.5 footprint. I was able to design the LED Driver and Status NOT Driver boards within the footprint. No way the Power Distribution Board would fit so I spaced it out so things were not crowded.

LED Driver Board
LED Driver Board

Board setup for LEDs

The I/O cards can’t supply much current so you will have to drive the LEDs / Incandescent Bulbs with transistors. Resistor values were first calculated, then verified/adjusted when tested on the breadboard.
It’s important to verify voltages and currents are within limits. I also noticed I needed different resistors values in the BASE line to obtain equal brightness in the Green and Red LEDs.
Resistors in the COLLECTOR line are not used for the incandescent bulb – piece of wire is soldered in.

LED Driver Board setup for the Annunciator incandescent lights (Lower Right)

LED Driver Circuit



Status NOT Driver Board
Pretty straight forward – I/O line comes in, gets split into two. One side goes out on left side of the card. The other one gets inverted and then out the right side of the card. Both outputs from this card go to the LED Driver card.


Power Distribution Board

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s