This circuit, with two operationals, was obtained from an old American publication. Operational amplifiers can be of modern equivalent types.
This power supply can supply symmetrical voltages of 5, 6, 9 and 12 V according to the xx of the...
We found this circuit with SCRs and unijunction in a Radio Electronics magazine from June 1969. The...
This timer triggers high-powered loads powered by the power grid. Times are given by C1 and the...