traidAn article in triggered my interest in the Traid project originally featured in

“Matseng started a challenge for himself where he intends to post a PCB project a week.” Check out the PCB a week tag for all his projects.

Now when I use a transistor I find myself always going back to the datasheet to double check the pin layout and orientation. If you’ve been there you know that you have to be really careful since sometimes it’s the top view of a package and sometimes bottom view. That’s when I decided that having a transistor test a.k.a. a Traid would be very helpful. It looks like a fairly simple design with a nice touch of having a a single CR2032 battery.

If a project like the Traid has to appeal to a wide audience it has to fit on single sided pcb. That’s what I set out to do, and am sharing here with you.

traid-bare-boardsThere is a small challenge here since I do need a place to sample the transistors. With a single sided pcb using through hole components that would imply using the bottom of the board. Since that would be awkward and very impractical I decided to sandwich a second, small and single sided, pcb on top of the other. This provides me with the sample space and attaching the boards was planned for with soldering a few wires through both board and maybe a dab of glue.



traid-part-populated-1The boards were designed and milled. With some difficulty the microchip 16F1503 was programmed. The board was designed without a programming header. I simply use a socket for the microcontroller so I can update it if needed or desired.

The schematic requires two 300K resistors. Confident that I have all the resistors I need in my parts collection I was mistaken. I have, a quite common, E12 collection, which does not offer a 300K resistor. I opted for using 270K ohm resistors instead and these appear to do the trick. I ordered the correct value at my favorite supplier and will swap them out lateron.

I added 4 legs to the board. They are good old spacers that typically hold a pc motherboard attached to the case.

Soon I’ll add more pictures and the cadsoft eagle schematic and board.

See part 2 for more pictures and a zip file containing the Cadsoft Eagle schematic and board files.

3 Responses to “Traid, the transistor tester – part 1”
  1. H. Hendawi says:

    I am closely following your project and despite my best efforts I was unable to find any Eagle models for the pic used (16(L)F1503).
    Can you tell me where did you find the Eagle lbr file for this pic?
    If you made it yourself and you wouldn’t mind helping me, could you please e-mail the file to me?
    Thank in advance for you consideration.
    H. H.

  2. ForScience says:

    Hi H H,

    I’ll post more details on my build soon and will include the eagle schematics as well. I think you can start with looking at the published schematic from the article I link to above.
    Here is a direct link to the original eagle schematic including the 16LF1503.
    The link above is from the author of the Traid. His work not mine. 😉

    Let me know if I can be of more help in your efforts, with the schematic or otherwise.

    B B

  3. […] « Traid, the transistor tester – part 1 Raspberry Pi Supply Switch single sided pcb » Nov 20 2013 […]