This circuit was found in a 1977 Radio Handbook. The MOSFET supports an equivalent. Capacitor C must be low leakage.
This constant current source from a 1980 publication can be used on a battery charger. Transistor Q1 may...
We found this circuit very simple in an old documentation. The relay is high voltage sensitive, but...
The network formed by resistors and capacitors determines the frequency of this sinusoidal...