With this circuit of a Popular Electronics from the 90's it is possible to test a diode with the oscilloscope visualizing its characteristic curve. The transformer can have currents starting from 100 mA.
This remote-control circuit was found in Radio Electronics magazine from June 1962. It drives a...
This is the receiver for the previous circuit we found in the December 1992 Radio Electronics...
This circuit with a few watts of power was found in the April 1995 issue of Electronics Now...