This circuit was found in a 90s Integrated Circuits Data Book. It interfaces a data line with a CMOS input, being powered by 5V. Can be used as a shield.
This circuit for VCR recording heads was found in the February 1990 issue of Radio Electronics magazine....
This very simple continuity tester uses a small 1.5 V lamp (type used in flashlights). Can be...
This commercial radio with 3 earphone listening transistors was manufactured in Japan in the...