This circuit is from the Linear Applications Handbook of the National Semiconductor of 1994. Transistors are common, but the integrated circuit is not easy to obtain today.
This filter rejects 1 kHz signals, being suggested by the manufacturer of the operational...
This is a simple variac type source found in the July 1962 Radio Electronics magazine. Voltage and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...