| 摘要 |
A feed circuit in a telephone set is connected via its input to the speech wires and transmits a feed voltage at its output, for example to the dialling keypad circuit of the telephone set. In order to simplify the circuit, the feed circuit and the dial pulse contact of the telephone set circuit form an integral module. To control the transmitted feed voltage, a control transistor with a negative feedback circuit is inserted for this purpose into the current path leading from the input to the output and receives dial pulses from the dialling keypad circuit on its control electrode.
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