摘要 |
A circuit integrity detection system for use in detecting the integrity of a sensing wire in a heating pad wherein the integrity of the sensing wire is determined by first driving one end of the sensing wire with a low voltage electrical test signal from a microcontroller, and then checking whether the test signal is present on the other end of the sensing wire, in order to distinguish the test signal from the standard AC line voltage present on the sensing wire, the electrical test signal is preferably of a different frequency than the standard 50-60 Hz AC line voltage. In one embodiment, the test signal frequency is approximately 30 kHz.
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