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.

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.