摘要 |
An A.C. powered smoke detector with supervision circuit for back-up battery. The circuit periodically and automatically, checks the power capacity of the back-up battery by momentarily disabling the D.C. power supply from applying D.C. voltage on a D.C. voltage bus while simultaneously applying a test load to the battery. If the test load voltage is too low, a low battery power capacity indication is provided. In one embodiment, the D.C. power supply is disabled by electrically disconnecting it from the battery. In another embodiment, a switch applies to effectively by pass the D.C. power supply and enable the application of the test load.
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