Here is a circuit diagram of an opto-coupler based adapter for a Polaroid SX-70 camera.
Keep in mind that the SX-70 camera has a trigger voltage of 4.5 V, the typical AG-bulb trigger circuit would be at 15V. So that circuit would have to be corrected. Those 18Ohms resistors are related to Flashbar control and of no interest here.
The choice of an opto-coupler enables switching quite high voltages. This approach would also be beneficial for a coupling device to trigger old style electronic flashes by modern cameras with electronic switching.
(I assume my SX-70 adapter contains a transistor.)
Last edited by AgX; 03-08-2013 at 06:33 PM. Click to view previous post history.