Power supply interface
First Claim
1. A power supply adapter for a mobile telephone unit having an operating voltage range between a maximum and a minimum operating voltage, said power supply adapter comprising:
- a cable having two ends, one end being connected to an external voltage source supplying power to the mobile telephone unit, the terminal voltage of said external voltage source being higher than the maximum operating voltage, and the other end being connected to a voltage regulator unit delivering a controlled output voltage within the permitted operating voltage range, said voltage regulator unit being provided in a housing adapted to be connected to the mobile telephone unit, wherein said cable is a resistive cable the resistance and length thereof being such that when the mobile telephone is subjected to a maximum load over extended periods a major part of the power losses arising from the voltage to be dropped by the cable and the voltage regulator will be absorbed by the resistive cable and the remaining power losses are absorbed by the voltage regulator.
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Accused Products
Abstract
The present invention relates to a power supply interface for a mobile telephone powered from a battery whose terminal voltage is greater than the maximum supply voltage of the mobile telephone. The invention is characterized by a resistive cable (4) which is wound helically and which is connected between an electrical contact (5) on a voltage supply source and an electronic unit mounted in a housing (6). The electronic unit includes a voltage regulator which delivers a controlled output voltage. The resistance of the cable shall exhibit certain conditions and shall have a length which is adapted to the resistance such that when at maximum load the mobile telephone will only be heated to a moderate extent; a maximum temperature of about 50° C., preferably 35° C., is intended.
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Citations
6 Claims
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1. A power supply adapter for a mobile telephone unit having an operating voltage range between a maximum and a minimum operating voltage, said power supply adapter comprising:
a cable having two ends, one end being connected to an external voltage source supplying power to the mobile telephone unit, the terminal voltage of said external voltage source being higher than the maximum operating voltage, and the other end being connected to a voltage regulator unit delivering a controlled output voltage within the permitted operating voltage range, said voltage regulator unit being provided in a housing adapted to be connected to the mobile telephone unit, wherein said cable is a resistive cable the resistance and length thereof being such that when the mobile telephone is subjected to a maximum load over extended periods a major part of the power losses arising from the voltage to be dropped by the cable and the voltage regulator will be absorbed by the resistive cable and the remaining power losses are absorbed by the voltage regulator. - View Dependent Claims (2, 3, 4, 5, 6)
Specification