This circuit has a sensitivity of 2uW. We found it in documentation from the 1980s. The integrated circuit is from that time. Equivalents can be tried.
This circuit is used to fire an auxiliary flash when the machine's main flash operates. With two...
Medium and high power partially burned can be used as diodes in a simple Power supply as shown in...
This circuit was found in an American documentation from 1976. We can assemble it with two 741,...