This circuit was found in a 1967 Electronics World. Transistor Q1 can be a TIP321 and Q2 can be a BC558. The indicator lamp is optional.
The circuit shown is from an old English publication from 1965. We can adapt the circuit to work...
If the reader needs to monitor a voltage and does not want an expensive or sophisticated solution. In...
August 2017 - Mouser Electronics is in stock with the PGA460 and PGA460 Q1 ultrasonic processors...