Found in Radio Electronics from the 90s, in the figure we have conventional voltage doubler with common components.
We found this simple frequency meter for low frequencies in an English publication from 1978. The...
This circuit is indicated for the control of resistive loads. When S1 is opened, the triac turns on...
A VCO or voltage-controlled oscillator, which uses only two of the LM3900 amplifiers, is shown in the...