Apparatus for controlling battery discharge
First Claim
1. Electrical device such as an electrical shaver or hair cutter comprising a DC motor adapted to be driven by a battery, an electronic switching device, and time measurement means for evaluating the time when said DC motor is connected to said battery, said electronic switching device, in response to said time measurement means indicating that a defined connecting time of said DC motor to said battery has elapsed, gradually reducing a current supplied to said DC motor so that a rotational frequency of said motor is reduced in steps or continually down to zero prior to deep discharge of said battery to limit risk that hairs could be snagged.
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Abstract
The invention is directed to an electrical device in which an electrical load is powered by a battery via an electronic switching device. A display means serves the function of indicating the charge status of the battery, and a time measurement means determines the connection time of the load to the battery. Following expiration of a predetermined connection time of the load to the battery, when the display means indicates the charge status "zero", the time measurement means will disconnect the electrical load from the battery by means of the electronic switching device.
13 Citations
12 Claims
- 1. Electrical device such as an electrical shaver or hair cutter comprising a DC motor adapted to be driven by a battery, an electronic switching device, and time measurement means for evaluating the time when said DC motor is connected to said battery, said electronic switching device, in response to said time measurement means indicating that a defined connecting time of said DC motor to said battery has elapsed, gradually reducing a current supplied to said DC motor so that a rotational frequency of said motor is reduced in steps or continually down to zero prior to deep discharge of said battery to limit risk that hairs could be snagged.
- 2. Electrical device such as an electrical shaver or hair cutter comprising a DC motor adapted to be driven by a battery, an electronic switching device, a voltage discriminator for detecting a predetermined voltage on said battery, and time measurement means which is started if the battery has the predetermined voltage, said electronic switching device, in response to said time measurement means indicating that a defined time has elapsed gradually reducing a current supplied to said DC motor, so that a rotational frequency of said motor is reduced in steps or continually down to zero prior to deep discharge of said battery to limit risk of hairs being snagged.
Specification