Transistor Tester

Jig used for matching discrete transistors. Sets up a constant current in the transistor under test, with 5uA and 500uA selectable by a DIP switch. Handles both npn and pnp.

I used an 8pin DIP socket to plug the DUT's in to. The red traces on the PCB are bare wires on the top side looped so they are easy to grab for measuring Vbe

Operation:

I have a piece of paper that I taped a piece of black electrical tape to, sticky side up, that I stick the transistors to and record the Vbe reading for. That way you can save and compare the Vbe's. It's fairly easy to get transistors to match within a 0.5 milliVolt if they are from the same lot.

Status
  • PCB built and stuffed
  • PCB tested and working
  • Transistor Tester schematic

    Transistor Tester PCB 2x size


    ©2001 Scott Bernardi