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US 5,212,836 AGranted
Power source control circuitry for an automotive portable telephone
AssigneeNEC Corporation
InventorAkimasa Matsushita
Life of this patent
Estimating the term…
Abstract
Power source control circuitry for an automotive portable radio telephone which is powered by a power source mounted on a motor vehicle via an adapter. When the telephone is mounted on the adapter, power is fed from the on-board power source to the adapter and telephone. When the telephone is removed from the adapter, the adapter is disconnected from the battery to eliminate wasteful supply of power from the power source to the adapter.
Claims5
Power source control circuitry for an automotive portable radio telephone which is powered by a power source mounted on a motor vehicle, comprising:
- switching means for providing a switching connection between said power source of said motor vehicle and an adapter and said telephone;
- ignition sensing means for sensing an output signal of an ignition system incorporated in said motor vehicle;
- power ON/OFF sensing means connected to a power switch of said telephone for inverting, every time said power switch produces an ON/OFF pulse, an output state of said power ON/OFF sensing means and holding said inverted output state;
- and
- control means for controlling said switching means in response to an output of said ignition sensing means and an output of said power ON/OFF sensing means, such that when said telephone is removed from said adapter, said switching means interrupts the connection of said power source and said adapter.
2 more elements
Dependencies are inferred from the claim text.