[Heady]

I got this schematic off the net for a adaptor for old flashes to be used on digicams. (Schematic in attachment)


I need clarification on two points:
1. What is ZD1, is it a zener diode?
2. The schematic of the triac has only one lead labelled "G", does it mean it doesn't matter which of the other leads are connected to the "+" and "-" ?


Sorry for being OT, this is my only source of electronic experts. Thanks.

 

[Pars]

Quote:

Originally Posted by Heady I got this schematic off the net for a adaptor for old flashes to be used on digicams. (Schematic in attachment) I need clarification on two points: 1. What is ZD1, is it a zener diode?

Yes, a 5.6V zener, I believe
Quote:

Originally Posted by Heady 2. The schematic of the triac has only one lead labelled "G", does it mean it doesn't matter the which of the other leads are connected to the "+" and "-" ?

Sorry, rusty on triacs and no ref material to look for it, so I'll defer on that one, although I would guess your assumption is correct. You might try to find a suitable triac at digikey, and see if you can snag a datasheet for it... that would probably tell you. And this isn't really that OT... even though you're not likely to spot too many triacs in headphone applications

Revised: Checked digikey and mouser, found a cross-ref at Mouser here. No application diagram, but other terminals are marked A1 and A2. Your schematic wasn't clear on which one goes where.

 

[mono]

A triac will conduct in either direction from T1 to T2, but IIRC, there needs be a small current through T1 and the gate to be triggered. Presumably the T1 pins is left of the T2, commonly they're |T1||T2||G| from left to right inline package. As for deciphering the circuit, it's not my forte' but I think T1 should be positive... but I could be wrong, hopefully someone else will verify this. Anyway I think it does matter which way it's oriented but not knowing for certain what the pinout is on yours...

 

[Heady]

Thanks so much to Pars and Mono. Given me more confidence to tackle this little project, appreciate it. I am hoping to use my flash collection from my film cameras with my digicam.