METHOD AND CIRCUIT FOR DETERMINING THE PRESENCE OF A FALSE CONNECTION BETWEEN AN ELECTRONIC APPLIANCE, ESPECIALLY A HOUSEHOLD APPLIANCE, AND A NETWORK ALTERNATING VOLTAGE SOURCE

摘要

The aim of the invention is to determine the presence of a false connection of an electrical appliance, especially a household appliance, which contains at least one part of an appliance and/or consumer and is connected to, or can be connected to, a network alternating voltage source comprising a plurality of phase conductors, in addition to an earth wire, via which alternating voltages phase-shifted in relation to each other can be applied. To this end, a blocking oscillator switching network block (SN) pertaining to the appliance and comprising a transformer (T) is used, in which energy is respectively accumulated during a conductive phase of a switching member (SW) via the primary side (w1) of the transformer, by a pulse voltage produced by means of the switching member (SW) following the rectification of a network alternating voltage, and the secondary side (w2) supplies energy respectively during a blocking phase of the switching member (SW) in question, following a conductive phase. Only the amplitude of the pulse voltage present during at least one conductive phase of the switching member (SW) on the primary side (w1) or on the secondary side (w2) of the transformer (T) in question is evaluated and optionally maintained.