Abstract: A controller system controls a plurality of lighting element arrays. The controller system comprises array selection module for selecting a lighting element array, voltage control module arranged to apply a voltage to at least the selected lighting element array, a common current source arranged to provide a current from the common current source to the selected lighting element array, and duty cycle control module arranged to control a ratio of the current to the selected lighting element array over a time sharing cycle.

Abstract: A controller system controls a plurality of lighting element arrays. The controller system comprises array selection module for selecting a lighting element array, voltage control module arranged to apply a voltage to at least the selected lighting element array, a common current source arranged to provide a current from the common current source to the selected lighting element array, and duty cycle control module arranged to control a ratio of the current to the selected lighting element array over a time sharing cycle.

Abstract: A temperature compensation circuit (10) for a crystal oscillator programmed by a single component (12), such as a resistor. The component (12) provides a voltage to an A/D converter (26). The digital signals (28) from the A/D converter (26) are divided and directed to separate signal generators (44,46,48,50,56) which control different aspects of the temperature compensation circuit (10). These aspects include a hot, cold, linear, balance and warp adjustment. The temperature compensation circuit (10) drives a varactor (18) which reactively loads a crystal oscillator (14) to compensate frequency over temperature. By using a single component (12) to program the circuit (10), an EEPROM is no longer needed which saves IC space and reduces IC processing steps, and the use of multiple external components to perform a compensation is avoided which further saves physical space.

Abstract: A substantially sealed frequency source (10) including a crystal oscillator (14) and a programmable IC (22) thermally and electrically coupled on a substrate (12). The IC (22) is accessed through an interface (26) with programming signals (42) so as to provide an analog temperature control signal (34) and a crystal oscillator frequency adjustment signal (36). The substrate (12) maintains a substantially constant temperature at a turning point (82) on a frequency-temperature response curve (80) of the crystal (64). The IC (22) allows programming of the source (10) after sealing to compensate for shifts in the crystal frequency-temperature response (80) due to sealing. The IC (22) provides electrical correction of the substrate temperature setpoint and the crystal oscillator frequency without mechanically or thermally disturbing the internal components of the source (10).