Slave Flash Trigger


Posted on May 3, 2012

The SCR is wired across the trigger circuit of the flash gun. Normally, the SCR is off, so the flash gun is able to cha


Slave Flash Trigger
Click here to download the full size of the above Circuit.

rge to its trigger voltage. Photo transistor Q1 is used to monitor the light level. When a high-intensity flash occurs, Q1 briefly conducts and supplies gate current to the SCR. That causes the SCR to turn on, which then triggers the slave flash gun via the hot-shoe adapter terminals. Once the flash gun has triggered, the SCR quickly turns off again. That happens because the current in circuit quickly falls below the SCR"s holding current. The resistor at the base of Q1 (RI) determines the sensitivity of the circuit. If you wish, you can reduce the sensitivity, simply by reducing the value of the resistor from that shown. The l-KOhmhm resistor between the gate and cathode of the SCR (R3) prevents the SCR from false triggering if high voltages are applied between the anode and the cathode. Q1 can also be a GEL14G2.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Voltage Comparator Switch
Water Level Alarm
Two Line Intercom circuit
Miniature-wideband-amplifier
Xor-gate-oscillator
3 channel Transistor Audio Mixer
10 or more switches using a microcontroller
switch mode power supply design of current load sense circuit
Single-speed motor excitation from the electrical braking circuit
Shared antenna amplifier power since the controller circuit diagram
Micro Wireless Monitor FM FM transmitter circuit



Top