| 摘要 |
A lamp outage indicator circuit for sensing and indicating outage of remotely located lamps in a vehicle. The lamp outage indicator employs a semiconductor sensing device to sense the voltage excursion which occurs when a lamp burns out. The sensing semiconductor is located in a bridge circuit to negate the effects of voltage and temperature fluctuations on the operating point of the circuit. Further, the sensing semiconductor device is located in the circuit so that in the normal operating state, a reference semiconductor device is on while the sensing semiconductor device is off. Lamp outage causes the current to shift from the reference semiconductor device to the sensing semiconductor device so as to turn the reference device off, and the sensing device on to energize an appropriate indicator. In one embodiment, the sensing semiconductor device is a light emitting diode while in a second embodiment, the sensing semiconductor device is a transistor.
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