Virtually any FET can be used on this voltmeter found in old documentation. The indicator is a microamper meter 0-100 uA and the accuracy of the circuit depends on the accuracy of the resistors used.
This high-gain circuit uses junction FETs (JFETs) and must be powered by somewhat high voltages. The...
This circuit counts 1 per second, displaying the value in binary. The circuit is TTL and must be...
Critical components of this project are the Geiger tube and the 300V battery. The battery can be...