Simple DIY Slave Flash Trigger for your camera

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Slave flash trigger is a circuit for triggering external flash without physical connection to your camera. Triggering is accomplished by light from the flash on your camera.

I used quick response components so that there is no noticeable delay between master and slave flash. On compact camera I can use shutter time up to 1/1000 of second.

List of material

  • Resistor 10k Ohm
  • Resistor 33k Ohm
  • Capacitor 100nF 100V
  • Thyristor C106
  • Silicon NPN Phototransistor BPY 62-2 or BPY 62-3
  • Switch
  • 9V battery snap connector
  • hot shoe for slave flash
  • prototyping PCB board




Flash units may have lethal high voltages on the terminals. Be extremely careful when working on something like slave flash trigger.

Franci KapelFranci is an experienced web developer who spends most of his free time hacking gadgets. Site was made to help others with their projects. Connect with Franci on Google+