Battery-driven watch with battery consumption display alarm

Abstract

The invention provides an advance alarm means incorporated with an electronic watch driven by a battery and fitted with a digital time display means. There is provided a detector sensing an abrupt voltage drop at the source battery. A selector represents its two states corresponding to the normal operating condition of the battery and to the voltage dropped condition thereof, respectively. This selector controls the feed of two different signal series to at least one electrically illuminatable elements of the digital time display means, depending upon the state of the selector and for providing an advance alarm before occurrence of an unacceptable voltage drop in the source battery.

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows: 
     
       1. In a battery driven electronic watch comprising a watch driver circuit, a battery for feeding current thereto, and a time-indicator operatively connected with said driver circuit, the improvement comprising a binary detector circuit connected to said battery for detecting when the source voltage falls below a predetermined level, a selector and drive circuit connected with the output of said detector, and an electrically illuminatable means connected with said selector and drive circuit, the brightness of said illuminatable means being modified from its normal state when said source voltage drops below said predetermined level in response to the binary logic output of said detector, said electrically illuminatable means being mounted on the front and normally visible surface of said watch. 
     
     
       2. In a battery-driven electronic watch comprising a source battery, an electronic watch driver circuit fed current therefrom and a digital time display means comprising a plurality of electrically illuminatable elements driven by said circuit, the improvement comprising a detector for sensing an abrupt voltage drop at the said battery, and a selector for selecting either a first signal series demonstrating the normal operating voltage kept at said battery or a second signal series of a different signal frequency from that of the first signal series and demonstrating a voltage-dropped condition of said battery, depending upon the state of said detector and derived from said driver circuit, at least one of said elements being supplied with either of said both signal series depending upon the state of said selector. 
     
     
       3. Electronic watch as set forth in claim 2 further comprising a sampler coupled with said detector and said selector, for impressing for periodically established short time periods a higher current to said detector than that of the normal operating current derived from said battery. 
     
     
       4. Electronic watch as set forth in claim 3, wherein said sampler comprises two series-connected toggle type flip-flops and an RS-flip-flop arranged downstream thereof. 
     
     
       5. The electronic watch as set forth in claim 1, wherein said electrically illuminatable means comprises an optical display element which is normally in its non-illuminated state but is caused to illuminate when said source voltage drops below said predetermined level. 
     
     
       6. The electronic watch as set forth in claim 5, further comprising a sampler coupled with said detector and said selector for impressing for periodically established short time periods a higher current to said detector than that of the normal operating current derived from said battery. .Iadd. 7. In a battery driven electronic timepiece comprising a timepiece driver circuit, a battery for feeding current thereto, and a time-depending display means operatively connected with said driver circuit, the improvement comprising a binary detector circuit connected to said battery for detecting when the source voltage falls below a predetermined level, a drive circuit connected with the output of said detector, an electronic sampler arranged between said timepiece driver circuit and said detector, said display means being connected with said driver circuit and a display operation of said means being modified from its normal state when said source voltage drops below said predetermined level in response to the binary logic output of said detector, said means being mounted on the front and normally visible surface of said timepiece. .Iaddend..Iadd. 8. In a battery driven electronic timepiece comprising a timepiece driver circuit, a battery for feeding current thereto, and a time-indicator operatively connected with said drive circuit, the improvement comprising a binary detector circuit connected to said battery for detecting when the source voltage falls below a predetermined level, a selector and drive circuit connected with the output of said detector, a sampler coupled with said timepiece driver circuit and said detector, a keeping means coupled with said sampling means, detector and selector for keeping the binary output of said detector, and an electro-optical alarm means connected with said selector and drive circuit, an operational mode of said alarm means being modified from its normal state when said source voltage drops below said level in response to the binary logic output of said detector, said alarm means being mounted on the front and normally visible surface of said watch. .Iaddend..Iadd. 9. The timepiece of claim 7, further comprising a divider adapted for dividing the source voltage into a part amounting to a value slightly above the threshold value of an inverter included in said detector, and a remaining part. .Iaddend..Iadd. 10. The timepiece of claim 8, further comprising a divider adapted for dividing the source voltage into a part amounting to a value slightly above the threshold value of an inverter included in said detector, and a remaining part. .Iaddend.