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.
We found this circuit in a 1977 publication for radio amateurs. It serves to test general purpose...
This circuit is from a 1998 Poptronics. The circuit triggers a buzzer after a certain time, waking...
This circuit for electronic voltmeter was found in a publication by Gernsback from 1960. The...