| 摘要 |
In a process for operating an electric device (1), especially an electric motor drive, an electric consumer (6) is fed from an a.c. network in that the input alternating voltage that is rectified and the intermediate circuit voltage so obtained is applied to the half bridges of a bridge circuit. Each of the half bridges has two bridge arms (7a, 7b) in which in any given case at least one semiconductor switch (8a, 8b) is arranged, to which control signals are applied through an actuation circuit (9a, 9b) fed from an auxiliary supply voltage source (16). Each of the bridge arms is connected to one of the poles (4) of the intermediate circuit voltage (5), and a test shutdown of the auxiliary supply voltage is applied to the actuation circuit (9a, 9b) of this semiconductor switch (8a, 8b) during a non-actuation phase of the semiconductor switch (8a, 8b) arranged in the relevant bridge arm. This test shut down is monitored by a measurement, and when an error occurs, at least the auxiliary supply voltages applied to the actuation circuits (9a, 9b) of the bridge arms (7a, 7b) connected to the other pole of the intermediate circuit voltage are shut down.
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