| 摘要 |
When the power is off, the central processing unit (CPU) stops memory function and preserves data by use of battery power. The circuit consists of a current control circuit with a Zener diode (D1), resistances (R1,R2,R3) and transistors (Q1,Q2), and a battery (BATT) part with a resistance (R4), a diode (D2) and a battery, and a voltage comparing part with an IC input devices (2,3) and resistances (R5, R6). The voltage comparing part controls CPU by comparing two powers (VCC, VBAT) and tansmitting a signal (POFF) to output device (7).
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