| 摘要 |
PROBLEM TO BE SOLVED: To extend battery life by suppressing surplus current consumption when the voltage of the battery being an operating power supply in a sleep mode of a radio meter reading terminal device surpasses a minimum operation maintenance voltage due to a rise in temperature. SOLUTION: A first battery 11 is a power supply that periodically stops receiving standby and supplies operating power of a sleep band where the minimum necessary limit operation of a CPU 7 performs, an A/D converter 21 measures a discharge voltage of the first battery 11 in a prescribed interval, a step-down regulator 19 supplies power as a minimum operation maintenance voltage via a switch A in the case the discharge voltage surpasses the minimum operation maintenance voltage, and the voltage of the first battery 11 is subjected to direct power supply through a switch C in the case the discharge voltage is the minimum operation maintenance voltage or is less than the minimum operation maintenance voltage.
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