JPS56675A - Analogue clock for car - Google Patents

Abstract

PURPOSE: To prevent needless power consumption, by controlling counting start of a counter, fast-feeding of hands based on the count value of the counter, and so on while interlocking with an engine key switch.

CONSTITUTION: When the engine key switch is turned off, switch means 10 interlocking with this switch is turned off to invert the output of means 10 to a low level, and the output of AND gate 40 becomes a low level through FFs 38, 36, and 30 and so on to prevent the driving pulse from frequency dividing circuit 4 and so on from being applied to stepping motor 18, and then, hands stop. Meanwhile, AND gate 42 opens by the inversion output of FF 30, and 12hr counter 12 counts time pulses after hands stop. When the engine key switch is turned on, means 10 is turned on, and motor 18 is driven through 12hr counter 14, coinciding circuit 16, and so on by fast-feeding pulses passing through gate 40, and then, the time of hands is corrected automatically. Consequently, the stepping motor of large power consumption is not driven when the clock is not used, and thus, needless power consumption can be prevented.

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