Of course, the current is extremely small, but a voltage of 300 V can be obtained from 9 V of a battery. The circuit is from an Electronics Now of May 1994. C1 adjusts the operating point.
This excellent quality transistor amplifier using Darlington transistors was found in a 1980s...
We find this circuit in an American 1980s documentation. Modern equivalent integrated circuits can be...
This circuit is intended to manipulate a transmitter (CW) from coded audio signals recorded on a...