This sensitive circuit was found in the June 1995 Electronics Now magazine. R1 can be from 10k to 1M depending on the desired sensitivity. Power is supplied by the relay.
This circuit was obtained in a Popular Electronics of the 90s. The circuit can be assembled with...
This circuit was found in the July 1990 Radio Electronics magazine. It is based on the 3-digit...
June 2017 - Kemet T521's new high voltage capacitors with capacitances up to 330 uF and voltages...