This circuit with the XR2206 IC squares the value of a voltage. The circuit was published in the April 1978 issue of Radio Electronics magazine and should be powered by a symmetrical 15 V source.
Figure bellow shows another circuit that allows adjustments in the duty cycle of the output...
This circuit is from an American publication of 1978. It can be assembled with modern transistors, since...
Found in a documentation for radio amateurs from the 90s, this circuit is suitable for RF...