This relay shield circuit for old computers was found in January 1983 Radio Electronics magazine. The relays are sensitive types with currents up to 200 mA.
In the circuit of the figure, when pressing S1 the sound varies according to the value of R2 and...
This 6-transistor Japanese radio from the 1960s used germanium transistors and had an output power...
November 2016 - Texas Instruments' new ISO773x triple channel digital isolators with 5,000 V...