This amplifier with fixed AC bias was found in a 1947 documentation. The circuit uses two transformers in the power supply and two full-wave rectifier tubes.
Found in a 90s documentation, this circuit triggers the SCR when there is an overvoltage in order...
The presented circuit makes use of operational ones that are not common in the market. More modern...
In the figure we have a monostable that is activated with switch S1 and pressed for an instant. The...