Indicated for 12 V systems, this circuit was obtained in a 90s Siliconix documentation. The components used are from the time and current equivalents can be tested.
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...