This high-gain circuit was found in an American publication from the 1990s. The circuit can use general purpose transistors and powered from a source or battery.
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...