Found in the September 1972 issue of Radio Electronics magazine, this signal injector is based on the HEP580. The circuit is powered by two batteries and its frequency is basically given by C1.
This 10 mA microammeter circuit can measure currents of 50 uA. The circuit is from a publication from the...
This circuit charges a battery to power a flashlight at night. The circuit is from an English...
We found this transistor siren in an old English publication. The transistors are from the era,...