Safety method and device for full-voltage power supply to a user apparatus only when required, and control assembly comprising such a safety device
First Claim
1. A method of detecting a condition requiring connection of a user apparatus to a feeder line voltage in response to a signal from the user apparatus, comprising the steps of:
- connecting the user apparatus to a voltage source through a detection impedance wherein the voltage of said voltage source is lower than the voltage of said feeder line;
detecting the waveform produced by said source at the end of the detection impedance;
comparing the detected waveform with a predetermined waveform, andconnecting the user apparatus to the higher voltage feeder line when the detected waveform at the ends of the detection impedance is distorted in comparison to said predetermined waveform.
2 Assignments
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Accused Products
Abstract
A method of detecting a condition requiring connection of a user apparatus with a feeder line comprises the steps of low-voltage power supplying the user apparatus through a detection impedance (17, 17a); detecting the waveform at the ends of the detection impedance; operating connection of the user apparatus with the feeder line when the waveform at the ends of the detection impedance is distorted in a manner that has been pre-established to be caused by actuation of a command in the user apparatus and requiring full powering of same. A device in accordance with the method comprises an analysis circuit (19, 37) detecting (by comparison with sample waveforms stored in a memory (20), for example) distortion of the waveform at the ends of the impedance (17, 17a) and consequently operating powering of the user apparatus.
20 Citations
19 Claims
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1. A method of detecting a condition requiring connection of a user apparatus to a feeder line voltage in response to a signal from the user apparatus, comprising the steps of:
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connecting the user apparatus to a voltage source through a detection impedance wherein the voltage of said voltage source is lower than the voltage of said feeder line; detecting the waveform produced by said source at the end of the detection impedance; comparing the detected waveform with a predetermined waveform, and connecting the user apparatus to the higher voltage feeder line when the detected waveform at the ends of the detection impedance is distorted in comparison to said predetermined waveform. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A safety device for supplying power to a user apparatus with a full supply voltage feeder line when a condition, that has been established to require this power supply, is detected, comprising
a low-voltage source for powering the user apparatus, when in a rest condition, through a detection impedance; -
an analysis circuit for comparing the waveform at the ends of the detection impedance with a predetermined waveform; a further circuit for connecting the user apparatus to the feeder line when said further circuit receives a signal from the analysis circuit indicating that a distortion between the compared waveforms is present. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification