This circuit was found in the October 1987 Radio Electronics magazine. The circuit is a PWM control with a 555. It appears that the 555 is missing a connection that would be pin 4.
This simple battery tester uses two transistors to drive LEDs of different colors, indicating the...
This circuit is from a 2005 Linear Technology application manual. The circuit uses a commercial...
This circuit was found in an English magazine in 1983 but can be assembled with BC558. However, the...