Electrical isolation device
First Claim
1. An electrical isolation device for isolating the electrical supply of a fuel burning appliance in response to an audio alarm, the device comprising:
- a microphone circuit operable to detect audio signals;
a lock-in amplifier connected to an output of the microphone circuit and operable to lock on to an alarm frequency and recover a modulated signal pattern of a potential alarm signal within the audio signals detected by the microphone circuit;
a processing unit operable to monitor an output of the lock-in amplifier for valid output signals through comparison of the potential alarm signal with a stored reference to determine whether the potential alarm signal is an alarm signal and output an alarm indication in response thereto; and
a switch operable in response to said alarm indication to disconnect the electrical supply of the fuel burning apparatus.
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Accused Products
Abstract
An isolation device is fitted to a mains electrical supply for a hydrocarbon burning appliance and is adapted to operate in response to an audible alarm signal emitted by a separately located detector, typically a carbon monoxide detector, to disconnect the power supply and thereby shutdown the operation of the hydrocarbon burning appliance. This can halt a potentially dangerous build up of CO in the vicinity of the appliance. The device includes a microphone circuit, a lock-in amplifier operable to lock on to a potential alarm signal within the audio signals detected by the microphone circuit, a processing unit operable to monitor the output of the lock-in amplifier so as to compare the potential alarm signal to a stored reference to determine whether it is an alarm signal and a relay operable in response to disconnect the electrical supply of the hydrocarbon burning apparatus.
20 Citations
20 Claims
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1. An electrical isolation device for isolating the electrical supply of a fuel burning appliance in response to an audio alarm, the device comprising:
- a microphone circuit operable to detect audio signals;
a lock-in amplifier connected to an output of the microphone circuit and operable to lock on to an alarm frequency and recover a modulated signal pattern of a potential alarm signal within the audio signals detected by the microphone circuit;
a processing unit operable to monitor an output of the lock-in amplifier for valid output signals through comparison of the potential alarm signal with a stored reference to determine whether the potential alarm signal is an alarm signal and output an alarm indication in response thereto; anda switch operable in response to said alarm indication to disconnect the electrical supply of the fuel burning apparatus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- a microphone circuit operable to detect audio signals;
Specification