The 4200B is an RMS voltmeter and is selective because it has a tuned circuit to adjust to a particular frequency. The unit uses discrete components and has an analog meter along with an LCD counter.

16×2 Parallel LCD ( Hitachi HD44780 driver compatible) How to make an Arduino Voltmeter As you may well know, Arduino’s analog inputs can be used to measure DC voltage between 0 and 5V (when using the ...

The voltmeter is an expanded scale type that indicates small voltage steps over the 10 to 16 volt range for 12 volt batteries. At the heart of the circuit is a ubiquitous dot-bar volt meter LM3914N ...

The 4200B is an RMS voltmeter and is selective because it has a tuned circuit to adjust to a particular frequency. The unit uses discrete components and has an analog meter along with an LCD counter.