Triggering a flash circuit with a voltage pulse across a transistor Answered
question from a newbie.
I'm working on a project for my (steampunk) daughter. For part of it I've taken the flash circuit from a disposable camera (PDF 1:Flash+MechanicalTrigger). This works just fine when I close the trigger mechanically. What I want to do is trigger it with the same pulse (from a 555 timer) that I'll be using to do other things at the same time. To this end I added a transistor as shown in PDF 2:Flash with transistorTrigger. My intention is to feed the 555 pulse to base, saturating it and triggering the flash.
Result, abject failure. Help!
The proposed triggering transistor is an MJE340(NPN). When set up as shown the indicator LED glows but voltage across Emitter-Base produces no result. When testing I noticed that if I mechanically make the collector-transformer connection it triggers a flash, even with no voltage across emitter-base.
Any ideas very gratefully accepted.