Voltage supply circuit for flow measuring device, has backup capacitor activated by control electronics during operation of circuit depending on input voltage supplied to circuit for voltage supply to primary coil

摘要

The circuit (10) has a transformer (26) with a primary coil (28) and two secondary coils (30, 32) that measure output voltage of the circuit. A backup capacitor (40) is charged by one of the secondary coils. The backup capacitor is activated by control electronics (42) during operation of the circuit depending on input voltage supplied to the circuit for voltage supply to the primary coil. The backup capacitor is charged by a voltage boosting circuit i.e. voltage doubling circuit (44). An independent claim is also included for a method for operating a voltage supply circuit.