2 articles were written in April 2013:

2013-04-04

SMT transistor test adapter

Another useful tool I built recently came from my AVR transistor tester build. I had build it with two different connector styles - one for attaching leads (via banana plugs), the other one for directly plugging in components. But this is lacking support for SMT components. I bought SMD tweezer probes (like these) on ebay recently, this covers all 2-pin components. But I had nothing to test or identify transistors.

So I took a small SOT23-3 breakout board (actually it has two footprints since the other side contains a SOT23-6 breakout), soldered a 3-pin header onto it and put it into the tester. It turns out that it gets a little bit wobbly that way, and one cannot add pressure to the device-under-test to get it seated firmly. So I added the left-over half of an IC socket to the other side, to act as support. Now the board sits firmly (though not exactly horizontal) in the socket.

the board in action

The wire on the right is needed because the breakout has one pin on the other side. The only drawback is that the numbering of pins on the board is in reverse to what the transistor tester uses. But I cannot put the board in the other way round because it then has no support. Maybe I will glue some foam under it one day…