Engine running time indicator
First Claim
1. A running-time indicator for use with an engine comprising generator means driven by said engine for generating electric power above and below a threshold power level when the speed of said engine is respectively above and below a predetermined speed, and electronic clock means including means for measuring time that elapses only while said generated electric power is above said threshold power level, said electronic clock means being electrically powered solely by said generator means.
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Accused Products
Abstract
A cumulative running time indicator for use with an engine has a ceramic resonator-controlled oscillator that drives an electronic divider, a multiplexer, and a stepping motor which is connected through a gear train to a mechanical display showing elapsed time. The running time indicator operates only when an electrical generator, which is mechanically coupled with the engine, produces sufficient voltage to operate the indicator circuits. Sufficient voltage is produced at all engine speeds above a threshold speed which is less than engine idling speed. The generator supplies ac voltage to doubler circuit that has two separate outputs -- one for supplying large pulses of current for the stepping motor, and a partially isolated second output for other electronic loads. A tachometer output signal is provided at an auxiliary output terminal and is buffered to prevent disablement of the running time indicator by short circuits and externally applied voltages at the auxiliary output terminal. The running time indicator is therefore self-powered, relatively secure from tampering, and accurate.
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Citations
17 Claims
- 1. A running-time indicator for use with an engine comprising generator means driven by said engine for generating electric power above and below a threshold power level when the speed of said engine is respectively above and below a predetermined speed, and electronic clock means including means for measuring time that elapses only while said generated electric power is above said threshold power level, said electronic clock means being electrically powered solely by said generator means.
- 9. A running-time indicator for use with an engine comprising electronic clock means for measuring and registering time when the engine is running, said clock means including means responsive to periodic current pulses for registering time, generator circuit means operatively coupled with said engine for supplying said current pulses to said clock means, said generator circuit means including a generator and first capacitance means for accumulating sufficient generated voltage incrementally to provide said current pulses, whereby said generator means supplies said current pulses although said generator means be sized only for providing power at a level lower than the power level of said pulses.
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16. A method for indicating the running time of an engine comprising the steps of
generating an ac voltage in a generator connected with said engine, doubling said voltage to produce a uni-polar output voltage by charging two capacitance means on successive half cycles of said ac voltage and adding the voltages of the two capacitance means in series, periodically discharging said two capacitance means by supplying periodic current pulses therefrom to drive a time register, and charging said capacitance means cumulatively in increments by a plurality of said ac voltage cycles of said generator between successive discharges by said current pulses, whereby said capacitance means serves both (a) for voltage doubling and (b) for accumulating sufficient energy from said plurality of generated voltage cycles to deliver said current pulses to drive said time register.
Specification