| 摘要 |
<p>An electronic telephone handset detector, for generating an output signal to an external controller indicative of a telephone handset being connected to or disconnected from a subscriber's set. A microphone input terminal is connected to a source of direct current such that in the event the microphone is connected to the terminal, direct current flows there through. A comparator circuit, connected in a circuit to the microphone input terminal, detects the current flowing through the microphone from the source of direct current and generates the aforementioned output signal in response thereto. The electronic handset detector is inexpensive, durable, and easy to manufacture.</p> |
