I was asked to mod the trigger voltage on an old vivitar 273 flashgun by my father in law. Trigger voltage was 327v. After mod it is now 5.24v. As this worked perfectly I will now mod my own 283 & 285. There is a little more room inside 283 & 285.
The components. 1 - 3020P Optotriac, 1 - Tic106D Triac, 1 - 330 ohm resistor, 1 - 5.6k ohm resistor. Also used heat shrink sleeve & 24 swg wire
The Victim, a rather tired looking Vivitar 273
The components in circuit
Took about 2 hours to complete, components just about squeeze in. Also took the time to clean sensor window & inner battery terminals. Result = 1 usable flashgun & 1 happy father in law!!