This high voltage source, found in 90’s Popular Electronics, can reach tens of thousands of volts. The Q2 transistor must have an excellent heat sink and the 9 V source is high current.
This low frequency oscillator with an operational amplifier of type 741 has adjustment of the mark...
This circuit was found in a Popular Electronics from the 90s. Transistors are general purpose...
The AT21CS11 memory device offers an extended voltage range to accommodate lithium-ion battery...