This circuit was found in a 1967 documentation. It is intended for triggering a xenon LASER. Observe the high operating voltages of the circuit. The components used are uncommon today.
This is one of many configurations with a 4-input mixer transistor that can be found on this...
This dimmer was found in the Electronics Experimenter Special projects of 1983. The circuit uses...
The operational amplifier used is the 741, but the configuration is valid for other operational...