In this 2001 circuit we have the way to trigger an SCR with a phototransistor. The circuit appears elsewhere in this section, obtained from publications from different eras.
This circuit, when connected to the 110 V power grid makes it possible to test capacitors with...
We can make an oscillating relay producing a rectangular signal taking advantage of the inductance of...
This basic voltmeter circuit has an input resistance of 2 M. The instrument is 100 uA and the...