Abstract: The present invention is an alarm system comprising an alarm handset (10) having a housing (30), a detector circuit (100) having means (102, 104) for receiving a preselected signal from a remote transmitter (40) and generating a first detection signal in response thereto, first sensing means for sensing change in a preselected parameter of the handset, warning means (300) for generating a warning signal, alarm means (400) for generating an alarm signal and control means (500) responsive to receipt of the detection signal to activate the alarm means (400). The control means (500) is operable to activate the warning means in response to at least one of receipt of the control signal and sensing of the change in the preselected parameter of the handset.

Abstract: The present invention is an alarm system comprising an alarm handset (10) having a housing (30), a detector circuit (100) having means (102, 104) for receiving a preselected signal from a remote transmitter (40) and generating a first detection signal in response thereto, first sensing means for sensing change in a preselected parameter of the handset, warning means (300) for generating a warning signal, alarm means (400) for generating an alarm signal and control means (500) responsive to receipt of the detection signal to activate the alarm means (400). The control means (500) is operable to activate the warning means in response to at least one of receipt of the control signal and sensing of the change in the preselected parameter of the handset.

Abstract: An alarm for detecting radiation and/or pollutants such as smoke, carbon monoxide or the like has a housing, a mounting plate for mounting the housing to a flat surface, cooperating means on the housing and the mounting plate engageable to secure the housing to the mounting plate, and an alarm circuit including a detector for detecting the radiation and/or pollutants. The alarm also has a switch in the alarm circuit in the housing and a magnet on the mounting plate, the arrangement being such that the magnet actuates the switch in response to engagement of the housing with the mounting plate thereby to arm the circuit. A battery compartment in the housing receives a battery for the alarm and stop means prevent proper engagement of the cooperating means in the absence of the battery. The mounting plate is generally planar having an upper surface and a through-opening for receiving a fixing such as a screw for fixing the mounting plate to a generally flat surface.

Abstract: An alarm for detecting radiation and/or pollutants such as smoke, carbon monoxide or the like has a housing (500), an alarm circuit (400) including a detector (DET1) for detecting said radiation and/or pollutants, first electrical connections (PL1, PL2) connectable to an external power supply for supplying power to the alarm circuit, and a control circuit (300) responsive to receipt of a preselected number of pulses over a preselected time period to apply a preset control signal to the alarm circuit (400). The alarm circuit (400) is responsive to the preset control signal to reset or test the alarm in dependence on the preset control signal.

Abstract: Alarm apparatus for detecting radiation and/or pollutants such as smoke, carbon monoxide or the like comprising a housing means housing an alarm circuit. The alarm circuit includes detection means for detecting the radiation and/or pollutants, alert means for alerting a user of the presence of the pollutant, and control means for controlling the alarm circuit. The alarm apparatus also includes an adaptor comprising first connection means configured for electrically connecting the adaptor to a source of mains electricity, second connection means configured for onward electrical connection to the alarm. The adaptor is configured for fixedly supporting the alarm relative to the source of mains electricity.

Abstract: A rechargeable power supply including voltage protection means through voltage dependent disconnecting means. A rechargeable power supply comprises at least one rechargeable cell connectable to a power source, a Zener diode connected to the at least one cell, and a bipolar transistor or a FET for selectively disconnecting the Zener diode from the cell in order to reduce any discharge of the cell through the voltage protection means. The Zener diode and the transistor are connected together in series and jointly connected across the cell in parallel.

Abstract: Provided is an alarm for detecting heat, radiation and/or pollutants. The alarm includes housing means and also includes detection means for detecting the heat, radiation and/or pollutants. The detection means, in turn, includes detection circuitry and a power source, and is contained within a cartridge that is mountable within the housing means and removable therefrom.

Abstract: A rechargeable power supply (10) comprises at least one a rechargeable cell (12) connectable to a power source (14), a Zener diode (20) connected to the at least one cell (12), and a bipolar transistor or FET (22) for selectively disconnecting the Zener diode (20) from the cell (12) thereby to reduce any discharge of the cell (12) through the voltage protection means (20). The Zener diode (20) and the transistor (22) are connected together in series and jointly connected across the cell in parallel.

Abstract: Provided is an alarm for detecting radiation, smoke and/or other air pollutants and includes detection means, first means for connection to a light fitting, and second means for connection to a light source. Electrical connection means connects the first means and the second means to enable the light source to be powered from the light fitting. In addition, a battery powers the alarm during periods of non-use of the light source, and isolating means thermally isolates the detection means from at least one of the electrical connection means, the light fitting and the light source.