This sensitive bio-monitoring circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit is powered by a 9 V battery and uses a low-impedance headphone output.
This circuit is from a Radio Electronics from 1950. The transistor was still new and called a...
This low power metronome produces pulses in a small loudspeaker. Pule rate is adjusted by P1 and...
Found in 1967 General Electric documentation this circuit appears elsewhere in this section. SCRs are...