| 摘要 |
<p>PURPOSE:To increase the lifetime of a battery power supply by supplying the power to a non-power-failure load via a main power supply, an auxiliary power supply and the battery power supply respectively. CONSTITUTION:When a main power supply switch 1 is turned on, the AC 100V is supplied to a main power supply 2 and an auxiliary power supply 3. In this case, the power supply 2 does not work and only the power supply 3 works to produce the auxiliary power supply voltage VAUX. This voltage is supplied to a power supply control unit 7 and a real-time clock RTC unit 6. When an action power supply switch 8 is turned on by a user, the power supply unit 2 is controlled by the unit 7 for generation of the normal power supply voltage VCC. The voltage VCC is supplied to a logical unit 5 and the unit 6. Thus the power is supplied to a device as a whole. When the application of the device is through, the user turns off the switch 8. As a result, the working of the power supply 2 is stopped and the supply of the voltage VCC is stopped to both units 5 and 6. While the power is supplied to the unit 6 via the voltage obtained from the voltage VAUX.</p> |
