This 555-based circuit was obtained from the 1995 Encyclopedia of Electronic Circuits volume 5. It triggers an SCR when the transistor is cut off.
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...