| 摘要 |
A plug detector for an electronic test instrument includes an isolation transformer interposed between a jack socket and a plug detection circuit. The jack socket includes a split jack arrangement in which two halves of a jack socket are connected to opposite ends of a primary winding of the isolation transformer. When the primary winding is loaded due to the insertion of a jack plug, the primary winding is shorted and the impedance of a secondary winding changes. The detection circuit detects the change in impedance in the secondary winding and generates a detection signal to indicate plug detection.
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