We found this circuit in the Radio Electronics magazine of May 1977. The transformer voltage is 6 + 6 V, and the current depends on the zener diodes and is in the order of 100 to 200 mA.
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...