Using a sensor from the time, this circuit was found in the 1992 Radio Electronics Handbook magazine. The circuit uses a pair of integrated two-digit A/D converters.
This is the circuit for the HM-10ª, an instrument sold by Heathkit. The circuit is from a Radio...
This circuit indicates when the monitored voltage drops below the value determined by the divider...
This circuit, from a 1975 Motorola manual, uses a power Darlington transistor of the time. We can...