This circuit is from a 1968 Electronic Design. The circuit uses transistors of the time that can be replaced with modern equivalents. More stages can be used to get higher tension.
This circuit was found in an American documentation from the 80's. The components are from that...
The circuit shown is from the Texas Instruments optoelectronics manual. It is intended for audio...
This circuit drive an LED with constant current determined by the values of the resistors of 10...