Here are a few photos of the bench test set up.
This shot shows the overall set up. I have a 12vdc bench power supply and the leads for this are at the top right. Black leads are -12vdc, red are +12vdc. Large red is the high voltage wire from the coil to the plug gap.
The coil used here is a NOLOGY transformer type coil of course any coil that works with the CDI can be used.
The white wire goes from the square wave generator to the point/trigger input on the Bosch 3 pin CDI.
This test can also be done with the CDI and coil in the 911 with the engine not running. Just disconnect the center wire on the rotor and hook that to the spark gap.
This is a little closer. Of course the black box with the red LED is the prototype basic square wave generator. This one is set for 2000 RPM on a 6 cylinder engine.
In this shot you can actually see a nice fat spark from the CDI which indicates the the CDI and coil are working well.
