Switch device incorporating capacitive oscillator
First Claim
1. A switch device comprising a face plate and a single switch oscillator having a capacitive component, the capacitive component having a first capacitor plate arranged adjacent the face plate, the face plate preventing electrical contact between the user and the oscillator whereby an object placed adjacent the face plate acts as a second capacitor plate thereby altering a frequency of the oscillator, control means being provided to sense the change in frequency and to actuate the switch in response to such a change,wherein the frequency from the oscillator is recalculated at fixed periods by the control means.
1 Assignment
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Accused Products
Abstract
A switch (10) comprises a face plate (16) and a single switch sensing oscillator (18) responsive to a switch activating presence. The oscillator (18) has a resistive component (36) connected to a sensing plate (38) which acts as a first capacitor plate. The face plate (16) is arranged to prevent electrical contact between the user and the oscillator (18). Any object, when placed adjacent the face plate (16), acts as a second capacitor plate which alters the frequency of the oscillator (18). A microprocessor (20) senses the smoke detector (62). In a further aspect the switch includes a mains electricity cable signal transmitter/receiver and a microprocessor whereby each such switch may communicate directly with another such switch.
10 Citations
15 Claims
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1. A switch device comprising a face plate and a single switch oscillator having a capacitive component, the capacitive component having a first capacitor plate arranged adjacent the face plate, the face plate preventing electrical contact between the user and the oscillator whereby an object placed adjacent the face plate acts as a second capacitor plate thereby altering a frequency of the oscillator, control means being provided to sense the change in frequency and to actuate the switch in response to such a change,
wherein the frequency from the oscillator is recalculated at fixed periods by the control means.
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8. A switch device comprising a face plate and a single switch oscillator having a capacitive component, the capacitive component having a first capacitor plate arranged adjacent the face plate, the face plate preventing electrical contact between the user and the oscillator whereby an object placed adjacent the face plate acts as a second capacitor plate thereby altering a frequency of the oscillator, control means being provided to sense the change in frequency and to actuate the switch in response to such a change,
wherein software within the control means automatically detects a frequency of a mains supply to which it is connected, via an AC zero detector circuit.
Specification