dpullum Loc: Tampa Florida

It has been 50years since I took electronic ckt (circuit) design!! Two projects. HELP NEEDED. Which of the goldmine Ocotcouplers can be used? What Ckt values?

1. Convert a SYK photo activated remote shoe to a sound activated shoe. Looks like converting would be relative easy because most componets are there.

2. Add Optocoupler ckt to simple shoe like the Sony to regular flash shoe (a simple hollow box) to have protection for use with flashes that may have too high a voltage.
www.goldmine-elec-products.com
has many at a very low price. i.e. you do not have to buy a minimum order of 200 like many sources.

example crts
http://www.pbase.com/photonouveau/image/31309799
http://www.pbase.com/photonouveau/300d_safe_flash_sync

BBNC

DPullum

Please don't get me started on optocouplers, LOL. Before retirement, I worked with a congenital idiot who, when faced with a failed electronic circuit, always pronounced the optocoupler was shot. Some of those circuits did not even have one. Apparently it was all he knew about electronics.

rayford2 Loc: New Bethlehem, PA

Flash shoe isolators are designed to protect a camera's electronics from a damaging trigger current surge. Usually from older style flash units being used on the newer cameras.
If you want to build one using this circuit you may have to do a little research to find the American equivilent for the 2 solid state devices; the other parts are common. If the flash doesn't work right decreasing the value of R2 in 10% increments may help.
If I wanted one of these I'd probably buy one from Ebay and forget the 5w soldering iron and heat-sink scenario.

dpullum Loc: Tampa Florida

And raford 2, those were just examples. I am too rusty on ckts to design rather than cobble. I took a year of electronics in grad school,,, but hay,, that was in 1963!!! There were only basic transistor then.. I grew up with tubes and wow the brain pain thinking in holes rather than zooming electron emissions... ouch.

YES, I recall once I designed and gave to QA/QC a flash light with cross polarization so that they could check the slubs per minute in monofiliment. slubs being bulges caused by over-polymerized polymer. the idiot wrote a paragraph saying the unit was worthless and published it in a monthly report... POed me,,, I suggested to the idiot that the battery ran down like any other flashlight!!! Called him up and ate him up and spit him out in little well chewed fragments.. "No man has ever talked to me that way." was his reply, mine was ,,, "Really, your wrong there too, I just did!" AS the saying goes " no good deed will go un punished."

The circuit given is a simple one,, but the part from Gold-mine is in the same family, but diff curves/specs, would work but bius resistor, and voltage would differ. Gold mine are cheap surplus parts,,, Expensive Op is $1 most are like 0.25.

The Sony adapter is just a shoe on a shoe, wired direct. Could I suppose Isolate by stacking a photo activated slave unit and couple with a male/male cord. Of of course use a small modern low voltage flash to set off the old big guy flash... But that is tooo easy. You know how that is,,,,a challenge is a challenge!!
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The reason for using for using a photo activated hot shoe for a sound activated ckt is because the parts are there.. looks like two selenium cells in series supply the trigger to a SCR trigger. That suggest to me that mod at the point of the selenium cell voltage then the circuit would be able to detect sound rather than light. Why do it? Well because it can be done... life is nothing without puzzles to solve..

dpullum Loc: Tampa Florida

Hay, all good things come to he/she (no gender bias) who waits. http://hiviz.com/kits/mte.htm

OK that is one down, now for the protection for the Sony adapter,,, that is were the infamous Opto comes in with a small battery.
OR
Would a zener diode work in a case like this? Simply shunting current over a particular voltage so camera only sees 6 volts?