Have you blown anything up yet.
Not as part of
this project!
235mA/10mA = 23 hours = approx. 82,000 1sec triggers.
Ah, good, my method was fine (though I deliberately chopped a third of the capacity off for "undisclosed reasons").
The flash's 380V only has to be shorted for about 4us so you could reduce the camera's trigger to just a 30us pulse through an opto or ~3ms for a small relay and even smaller batteries would last forever.
You can usually see the trigger transformer ringing by bringing the flash near to a scope probe, no physical connection is needed, it only rings for a few us, then there's another 5-8us delay before the tube lights, I've watched it many times!
So I modified the Sunpak. It's a Sunpak 134 - which, according to
this site should have a trigger voltage of "only" 50-ish volts... so I don't know why my unit sits at 380V (were there different revisions of the same flash? ::shrugs:: )
There was barely enough space for my modifications - I decided to go for the optocoupler since I had it to hand, and it was smaller. Optocoupler powered by a CR2032 stuffed down a tiny gap between the PCB edge and the case, triggers the TRIAC on hard via an NPN transistor. Ended up using SMD parts on some stripboard and then cutting the remainder off with side cutters and filing the edges down to keep the size as low as I could manage.
The only problem I see is the creepage distance - I cut the board with a hacksaw and soldered the optocoupler across it (about a 5mm gap) - but because it's wedged in a small space, there may be creepage across the side of the case (I put a sil-pad in there, but I don't know how that performs when it comes to surface creepage.)
I think I'll keep it away from my camera for now just in case: I'll relegate that one to wireless triggering once I can afford that!
As for the Hanimex TZ7000... turns out it runs with a trigger voltage of 4.4-4.5V - I'd call that a win!
I believe your Pentax uses a standard hotshoe, but my memory is the Hanimex is for a Minolta hotshoe. If that's true, the Hanimex will not fit on your Pentax. I mean it physically will not fit. You didn't say what model your Sunpak is.
I would just encourage you again to use these old flashes off-camera. You will find that the results you get with off-camera lighting make it look like you know what you're doing, even if you don't, and of course your camera would not be at risk from high voltage. You would need a light stand, an umbrella adapter and an umbrella, plus some way to deal with the high voltage. And you can get a basic wireless trigger set for $20. This would be manual triggering of course - both camera and flash(es) in manual mode. None of this ETTL rubbish. :-)
Aye, I didn't realise the wireless units were that cheap - I may partake once I get enough money together for a new flash.
The Sunpak is a "134" - though other people are only measuring around 50V on their trigger pins, so I don't know what mine is doing (different board rev maybe? ::shrugs:: ).
The Hanimex is indeed supposed to fit a Minolta (Maxxum 7000?) camera, but it seems to fit my pentax and fujifilm no bother. There is an extra pin for the AF illuminator and the functions of the other two pins are flipped round - BUT the foot of the flash is actually longer than the modern ISO hot shoe, so they don't make contact anyway. The trigger pin makes contact though, so it ends up working fine anyway: I'd call that a win!
I might add in a similar optocoupler + battery anyway, just to be on the safe side. It's thyristor triggered (I think?) and there is some control circuitry in the bottom module. Oh, there's an interesting point about the construction - the Hanimex flash is two modules that clip together - the bottom module contains what I assume is some control circuitry, and connects to the rest of the flash via a board-edge connector. It's entirely enclosed and can be disconnected with no tools from the rest of the flash - I assume they reused the control circuitry across several different flash units - just a matter of slotting it in: interesting!