Circuit arrangement for measuring alternating voltage and for the simultaneous repressing of switch-off voltage peaks

摘要

The circuit arrangement prevents the voltage value indicated during the testing of fault current or fault voltage protection switches in systems with inductances from being falsified at the instance of responding due to voltage peaks occurring at the time. For this, a possibility of no longer indicating the half wave within which the switching-off occurs was found. This is done by means of a relay-controlled circuit in which two relays (9, 13) are alternately controlled by the positive and negative half waves of the alternating current to be measured in such a manner that when one contact (4) is closed, the second one (5) is opened and conversely. During this process, a buffer capacitor (3) is charged up by one half wave and during the other half wave this charge is transferred to a storage capacitor (8), the charge of which is then indicated. IMAGE