Solar energy operated automatic charge device for electric appliances
AssigneeU.S. Philips Corporation
InventorsLeo Bertram, Hugo Schemmann, Theodor Husgen
Life of this patent
Estimating the term…
Abstract
A charging device for accumulator-operated small electrical appliances, for example, electric dry-shavers, which are energized by rechargeable accumulators (24) which can be charged by means of a charging device (15) including solar cells (11). The charging device includes an energy buffer (20) which is connected parallel to the solar cells for buffering the solar energy when the charge capacity of the solar cells is below the charge current threshold of the accumulator. The buffered solar energy is supplied to the accumulator when a discharge current of the energy buffer exceeds the charge current threshold of the accumulator and flows until the discharge current falls below the charge current threshold.
Claims20
A charging device for small electrical appliances whose energy is supplied by a rechargeable accumulator comprising:
- solar cells for converting light energy into an electric solar cells voltage, an energy buffer for storing electric energy thereby to develop a buffer voltage indicative of the amount of electric energy stored, first means responsive to the solar cells voltage and to the buffer voltage for coupling the energy buffer in parallel with the solar cells for buffering the solar energy if the solar cells voltage is equal to or greater than the buffer voltage and independently of the accumulator voltage, and second means controlled by the buffer voltage and a given threshold voltage for coupling the accumulator in parallel with the energy buffer for supplying the buffered solar energy to the accumulator if the buffer voltage exceeds the given threshold voltage and independently of the solar cells voltage.
A device for charging a rechargeable accumulator from a source of solar energy comprising:
- a solar cell arrangement for converting light energy into an electric solar cell voltage,
- an energy buffer for storing electric energy thereby to develop a buffer voltage which is indicative of the amount of stored electric energy,
- a switching device for coupling the solar cell arrangement in parallel with the energy buffer when said electric solar cell voltage is equal to or greater than the buffer voltage, and
- switching means for coupling the rechargeable accumulator in parallel with the energy buffer when the buffer voltage exceeds a predetermined threshold voltage.
Dependencies are inferred from the claim text.