摘要 |
An uninterruptable power supply for use with an Internet Telephone or Internet Telephone Cable Modem comprises a power supply and a load. The power supply has an AC/DC converter for producing converter DC, and also a rechargeable battery. A DC output multiplexer selects one of such DC sources and furnishes it to the load. The multiplexer has an input control signal for switching the DC source to a battery, and an output indicator indicating when the battery is acting as the DC source. The load includes a controller which generates this test signal at times when it is useful to test the battery, and accepts the indicator signal to know when the battery is providing this current. The controller includes a test function for measuring the reserve charge of the battery by measuring the temporal voltage drop and time of this temporal voltage drop with the use of an A/D converter. Additionally, the controller measures the charge and discharge intervals of the battery. The controller includes NVRAM which stores the test state, and an internet connection for the passage of messages to and from the internet.
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