Found in a 1960 General Electric documentation, this crowbar circuit blows the fuse in case of excess current. The circuit is for 12 V sources triggering between 14 and 17 V.
This circuit of a 1978 American publication monitors a telephone line by triggering a relay. The...
This interesting FET-tester circuit was obtained from an old American documentation. The bipolar...
This old VHF TV booster that also serves FM was found in Radio Electronics magazine from April...