This circuit was found in an article about the 555 in the November 1992 Radio Electronics magazine. The circuit uses a 12 V relay and has two timing ranges.
I found this circuit in an English magazine from July 1982. The circuit is still viable by using...
Suggested by National Semiconductor in documentation from the 90s, this circuit makes use of an...
This circuit was found in an American 1980s documentation. Equivalent operational amplifiers can be...