Found in old documentation, this oscillator operates with high voltage. The diode must be of the appropriate type with low current and an inverse voltage of at least 100 V.
The purpose of this 1-transistor amplifier is to allow the use of a milliammeter in an application...
This circuit causes one LED to light up if the voltage falls below the value set in R3 and the...
This circuit was found in a 1986 documentation and it may be difficult to obtain some of its...