| 摘要 |
In the circuit arrangement for the operation of polarity-dependent electronic control devices in telephone sets, a bistable relay is used which is excited by the discharge current of a capacitor, which has charged itself on the polarity of the connection lines, in such a way that its contacts connect the voltage to electronic control devices with the correct polarity. A voltage drop (forward voltage) of the type occurring in electronic switching means is thereby prevented.
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