This is the transmitter for a remote-control system published in the August 1986 issue of Radio Electronics magazine. The circuit uses two 555 CMOS transistors to drive two series LEDs.
This circuit was obtained from an American documentation from the 1980s. The T1 triggering...
Found in a 1974 Ferranti manual, this circuit uses diodes to limit the voltage on the transistors. The...
This circuit is from an English publication of 1991. With it you can use a common multimeter on...