Roman numeral display (CB22160E)

This circuit shows numbers I II and III when mounted on its side, depending on the position of the selector switch.

Adapter for transistor test using a multimeter (CB3925E)
We found this adapter in a 1970s American documentation on instrumentation. It is suitable for analog...
560 kHz to 1 MHz VCO (CB21499E)
This circuit was obtained from an Electronic Design from 1964. Transistors admit modern...
Nicad Charger (CB13543E)
This charger is from an old publication of 1975. The PNP transistor can be the BC558 and the NPN...