Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally selected. The components are from that time, not easy to find today.
This General Electric circuit is from the 80's. The PUTs used in this meter are not common...
The DC output of this circuit corresponds to the RMS value of the input voltage. The circuit is...
This circuit with different colored indicator LEDs has an expanded scale. We found it in the March...