Flash slaves are used when you need to supplement one flash unit with one or several more. This slave trigger simply triggers those other units. It does this by “seeing” the first flash (using a phototransistor) and triggering the other flashes a few microseconds later. The sensitivity of the circuit is adjustable to compensate for ambient light or dimmer than usual master flashes.
Part Total Qty. Description
R1 1 47K Linear Pot
R2, R3 2 3K 1/4W Resistor
R4 1 220 Ohm 1/4W Resistor
R5 1 680 Ohm 1/4W Resistor
C1 1 10uf 25V Electrolytic Capacitor
C2 1 0.047uf 25V Ceramic Capacitor
Q1 1 2N5777 NPN Darlington Phototransistor
Q2, Q3 2 2N3904 NPN Transistor 2N2222
SCR1 1 400V 2A SCR
S1 1 1A 120V SPST Switch
P1 1 Plug to match jack on slave flash
MISC 1 Knob For R1, Wire, Board.
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