Does anyone have a circuit that will trigger a strobe light to flash in response to a TTL logic signal? Specifically, if I have a strobe circuit capable of flashing 1000 times per second, it seems like it should be possible, under logic control, to get pairs of flashes at say, 5 msec apart, with the pairs separated by much longer intervals, e.g., 100 msec.

Most strobe circuits I've seen use some kind of relaxation oscillator to periodically trigger the flash tube. These are fine if all you want are single flashes at a not-too-specific rate.

I know there are camera flash units that will flash in response to a switch closure, but these don't usually recharge fast enough to put two flashes together in the space of 10msec or less.

My hunch is that if I dump the charge from a small cap into the primary of a trigger transformer, through a switching device of some kind, the tube can be made to flash. The problem is dumping the cap charge quickly enough to get the trigger spike, and not toast the semiconductor with the backlash from the transformer input.

The other concern is that since the trigger circuit basically produces nasty voltage spikes, how to go about isolating the control logic from the spikes.


2 Answers 2


This circuit uses an SCR to trigger the strobe. There is an optoisolator between the SCR and the trigger circuitry, so as long as the SCR is rated at a high enough voltage (400V in this case), you should be able to easily trigger the SCR through the optoisolator using TTL voltages without problems.


Not having looked at strobe light circuitry, I would say look into solid state relays or optoisolators as starting point and see how to fit them into the design.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.

Not the answer you're looking for? Browse other questions tagged or ask your own question.