The opto thyristors in my cheap Cactus triggers are rated at 400 volts. You could not possibly find any for sale which would be destroyed by voltages in the tens of volts. I couldn't even find a similar device rated as low as 250 volts which is what most modern cameras are rated at. This makes me think that modern cameras use a 400 volt device and the manufacturers state 250 volts for a large margin.
Originally Posted by Rudeofus