Another entry chronicling my adventures assembling and testing my Firestarter Boards. Part one can be found here. I was busy over the last week, so there was a larger gap between testing than I expected.
An overview of work on the BU Rocket Propulsion Group Firestarter boards.
For BU Rocket Team I needed a quick way to test E-Matches and get two readings off of then, namely current draw and to monitor voltage sag from a 3.7V Lithium Ion battery which will eventually be powering the board that is controlling the motor.
At first I tried to test using an IRF820 I found. The main reason was that I could quickly breadboard a test rig, get my data and call it a day. However, the devil is in the details, because at 3.7V this transistor simply can't draw more than 50mA or so. However, for the actual controller board, called Firestarter, I was going to use SI2308BDS N-Channel FETs, which have a much nicer V_ds vs I_ds curve for our application. The SI2308s only come in a SOT-23 package. There are methods to get around this, but I decided to take the opportunity to try PCB Etching.