Interface circuit for actuating an electrical device and circuit arrangement for actuating an electric motor therewith

Abstract

An interface circuit for actuating an electrical consumer, especially a pole-changing rotary-current induction motor, with a first contact element assigned to a signal line carrying an alternating voltage signal to generate at least two different control signals. A circuit arrangement is provided for actuating an electric motor, especially a pole-changing rotary-current induction motor, with a control switch element having an aforementioned interface circuit, which is connected via a signal line to a motor control of the electric motor. In order to achieve a reduction in the number of signal lines required as compared to a parallel transmission, while at the same time preserving the easy fault diagnosis, an encoding diode (10) is hooked up in series before or after the first contact element (6a, 7a) in the signal line (4) and a further second contact element (6b, 7b) is arranged in parallel with the encoding diode (2), so that depending on the positions of the first contact element (6a, 7a) and the second contact element (6b, 7b) three different control signals (19a, 19b, 19c) can be generated.

Dependencies are inferred from the claim text.