This PLL circuit was found in the April 1978 issue of Radio Electronics magazine. The circuit is powered with up to 15 V voltages from a symmetrical source.
This circuit is from old European documentation. R1 depends on the output voltage of the...
This SCR circuit activates a buzzer when triggered. The circuit is from a Popular Electronics from...
This 130 V drive uses an integrated circuit not very easy to find, which is the LM143. The circuit is...