ELECTRONIC SEAT SENSING SWITCH
First Claim
1. In a vehicle, an electronic seat sensing system for determining the presence or absence of an occupant at each seat position comprising:
- a plurality of seat position electrical circuits each comprising in series a first buffer, a second buffer and an amplifier, one of said circuits operatively coupled to each vehicle seat position to be sensed;
sensor means operatively coupled to each of said seat positions and responsive to the body capacitance of a vehicle occupant manifesting their presence in said seat position, said sensor means electrically connected to the junction between said first and second buffers respectively in each of said seat position electrical circuits for controlling the input capacitance of said second buffer; and
an oscillator having its output electrically connected to the input of each of said first buffers in each of said seat position electrical circuits, said oscillator providing a continuous source of pulsating electrical signals independently to each of said first buffers of said electrical circuits for generating an electrical signal from said amplifier according to the response of said sensor means, said oscillator unaffected by the body capacitance of any or all occupants.
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Accused Products
Abstract
An electronic seat sensing switch placed within the cushion of a motor vehicle seat, senses the presence of an occupant sitting thereon. The sensor responds to the body capacitance of the occupant to electrically '"'"''"'"''"'"''"'"'load'"'"''"'"''"'"''"'"' the input to a complementary MOS, C/MOS, buffer and thereby blocking an alternating signal from an oscillator from being conducted by the buffer. The oscillator is isolated from the sensor by a second C/MOS buffer allowing a number of parallel switches to be electrically responsive to the output of the generator. The sensor does not affect the operation of the oscillator.
20 Citations
5 Claims
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1. In a vehicle, an electronic seat sensing system for determining the presence or absence of an occupant at each seat position comprising:
- a plurality of seat position electrical circuits each comprising in series a first buffer, a second buffer and an amplifier, one of said circuits operatively coupled to each vehicle seat position to be sensed;
sensor means operatively coupled to each of said seat positions and responsive to the body capacitance of a vehicle occupant manifesting their presence in said seat position, said sensor means electrically connected to the junction between said first and second buffers respectively in each of said seat position electrical circuits for controlling the input capacitance of said second buffer; and
an oscillator having its output electrically connected to the input of each of said first buffers in each of said seat position electrical circuits, said oscillator providing a continuous source of pulsating electrical signals independently to each of said first buffers of said electrical circuits for generating an electrical signal from said amplifier according to the response of said sensor means, said oscillator unaffected by the body capacitance of any or all occupants.
- a plurality of seat position electrical circuits each comprising in series a first buffer, a second buffer and an amplifier, one of said circuits operatively coupled to each vehicle seat position to be sensed;
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2. The electronic seat sensing system according to claim 1 wherein said sensor means comprises a flat U-shaped mylar member having one broadside thereof copper plated.
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3. The electronic seat sensing system according to claim 1 wherein said sensor means comprises a flat U-shaped mylar member having one broadside thereof aluminum plated.
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4. An electronic capacitive responsive sensing switch comprising:
- an oscillator for generating a continuous train of fixed frequency electrical signals;
a first buffer electrically connected to the output of said oscillator;
a first capacitor electrically connected in series to the output of said first buffer;
a second buffer electrically connected in series to said capacitor and responsive to the a.c. signals coupled thereto by said first capacitor;
a second capacitor electrically connected in series to said second buffer;
an amplifier electrically connected in series to said second capacitor responsive to the a.c. signals coupled therefrom for generating a first electrical signal and responsive to the absence of the a.c. signals for generating a second electrical signal; and
a sensor member comprising a U-shaped member electrically connected to the junction of said first capacitor and said second buffer, said sensor responsive to a capacitive load in the near proximity thereof for electrically loading said second buffer and thereby causing the second electrical signal to be generated from said amplifier.
- an oscillator for generating a continuous train of fixed frequency electrical signals;
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5. The Electronic capacitive responsive sensing switch according to claim 4 wherein said sensor member is a flat U-shaped mylar member having copper plate on one broadside thereof.
Specification