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 setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors...
This circuit is based on a common cathode 7-segment display. The circuit is based on CMOS...
The existence of field effect transistors at the input of the integrated circuit (operational...