This long interval timer was found in the September 1976 issue of Radio Electronics magazine. The output can be used to control a relay. The circuit achieves timings of up to 14 hours.
We present a DC-DC converter circuit that can operate with input voltages from 2.4 V to 14 V and...
We found this circuit in a 1977 Radio Shack brochure. Transistors can be the most modern BC548 for NPN...
This circuit can be used as an input shield for microcontrollers or other TTL circuits. The power...