Found in American documentation from the 90s, this circuit has an input resistance of 100 teraohms. The circuit uses a MOSFET from the time, but modern equivalents can be tested. The indicator instrument is a microammeter.
Found in American documentation from the 90s, this circuit has an input resistance of 100 teraohms. The circuit uses a MOSFET from the time, but modern equivalents can be tested. The indicator instrument is a microammeter.