Abstract: A flashing warning light apparatus wherein there is provided one or more light-emitting diodes, the light-emitting diode being driven in a pulsed manner to achieve light output at a selected flash rate, with control means adapted to detect any light-induced signal from the same light-emitting diode or diodes during periods when the light-emitting diode is not emitting light, said signal being dependent on the level of ambient light. The same diode or diodes can be at a focus center of a reflector. A magnitude of any signal can then be used to determine whether the ambient light is such that the warning light should operate.

Abstract: A controller adapted to control the temperature of a heating elements with a wide range of positive temperature coefficient of resistance, including very low values, using a sensor in line with the heating element. The controller is able to take account of non-constant mains power supplies and variation in the element resistance over time.

Abstract: A bi-directional bus buffer for applications using the I2C and SMBus, or other bus systems operating on similar principles, able to extend the bus load limit by buffering both the SCL and SDA (clock and data) lines, allowing capacitive loads of up to the limit of 400 pF on both sides of the buffer. With the use of an enable function, sections of the bus can be isolated, and then, thorough the use of a number of these buffers, different parts of the system are able to be isolated, and brought on-line successively or in a controlled manner, permitting a controlled start-up, and operation at maximum performance speeds while still having a diverse range of components, operating speeds and loads.

Abstract: A controller adapted to control the temperature of a heating elements with a wide range of positive temperature coefficient of resistance, including very low values, using a sensor in line with the heating element. The controller is able to take account of non-constant mains power supplies and variation in the element resistance over time.

Abstract: A relay arcing protection arrangement for a relay of a type including an electromagnetic coil adapted to be connected to a control circuit and effect an opening or closing of at least two electrically conducting contactors in response to a transition signal from the control circuit, including electronic circuit means to detect arcing across the contactors, and to effect activation of a solid state current connection means providing a parallel current pathway to the electrical connectors when arcing is detected during such a selected period of time after activation.