This simple tester was found in a Popular Electronics from the 90s. The circuit is powered by two 9 V batteries since it requires a symmetrical source.
In the 110 V network, capacitors of 200 V or more and in the 220 V network, capacitors of 400 V or...
This amplifier with an OTA has a gain of 40 dB. The power supply must be symmetrical. Found in...
Found in a 1967 American publication, this circuit with feedback for two transistors has a gain of...