This simple circuit to monitor the frequency of the power grid uses an analog indicator. The adjustment trimpot can be 4k7 and the indicator is 100 mA full scale.
The idea of this circuit is to press the button in such a way that the flow of the LED in the...
This is the receiver for the previous circuit we found in the December 1992 Radio Electronics...
This circuit was obtained in a documentation from the National Bureau of Standards of 1968. The...