A=D circuit for analogue measuring voltages - has opto-electronic coupling between switched storage capacitor circuit and output

摘要

The circuit allows analogue measuring voltages to be converted into potentially separated digital signals, using successive charging and discharging of a storage capacitor (2), under control of a switch stage (5). The discharge resistance (6) is connected in series with an LED (7) forming part of an opto-electronic coupling (9) the other part of which is provided by a phototransistor connected across a pair of outputs (A1,A2) providing the digital signal. Pref. the switch stage (5) has a comparator allowing the period of the digital signal to exhibit a defined ratio relative to the received measuring voltage. ADVANTAGE - Applicable to wide measuring range.