A controller includes a connection determination unit configured to determine whether a device and a device control apparatus are directly communicatively connected to each other. The device control apparatus functions as a type 1 device control apparatus under a condition where the connection determination unit has determined that the device and the device control apparatus are directly communicatively connected to each other. On the other hand, the device control apparatus functions as a type 2 device control apparatus under a condition where the connection determination unit has determined that the device and the device control apparatus are not directly communicatively connected to each other.

The lighting control device includes a controller. The controller generates a second dimming signal corresponding to a measurement result of brightness of surroundings in the first mode and generates a second dimming signal corresponding to a first dimming signal in the second mode. The controller selects the first mode and start operating in the first mode when receiving the first dimming signal having a third duty cycle not falling within a range from a first duty cycle corresponding to an upper limit of the dimming level to a second duty cycle corresponding to a lower limit of the dimming level. The controller selects the second mode and start operating in the second mode when receiving the first dimming signal having a duty cycle falling within the range.

A control apparatus using variations in conduction angle as control command, wherein a conduction angle modulation module of a traditional leading edge cutoff dimmer is arranged in parallel with a resistance module, so as to enlarge the minimum conduction angle of the leading edge dimmer. The modulation range of the conduction angle of the conduction angle modulation module may be set to a smaller range, so that the modulation range of the resistance module will not be uncertain due to different setting values of the variable resistance, whereby the circuit at load end can be identified readily and function mode switching facilitated to achieve the effect of multiplexing control.

A two-wire load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

The lighting control device includes a controller. The controller generates a second dimming signal corresponding to a measurement result of brightness of surroundings in the first mode and generates a second dimming signal corresponding to a first dimming signal in the second mode. The controller selects the first mode and start operating in the first mode when receiving the first dimming signal having a third duty cycle not falling within a range from a first duty cycle corresponding to an upper limit of the dimming level to a second duty cycle corresponding to a lower limit of the dimming level. The controller selects the second mode and start operating in the second mode when receiving the first dimming signal having a duty cycle falling within the range.

An electronic ballast system for signage light includes a first lamp string, a second lamp string, a first inverter and a second inverter. The first lamp string includes at least one first lamp tube. The second lamp string is connected with the first lamp string in series, and includes at least one second lamp tube. The first inverter is connected with the first lamp string for driving illumination of the first lamp string. The second inverter is connected with the second lamp string for driving illumination of the second lamp string. A frequency difference between a frequency of the first inverter and a frequency of the second inverter is in a range between 500 Hz and 5 kHz.

A control algorithm for operating a fluid disinfecting system by UV radiation, wherein the UV radiation is generated by at least one UV lamp including a pair of heating cathodes having a discharge voltage (U.sub.D), the UV lamp is operated by an electronic ballast unit equipped with the control algorithm for adjusting the UV power of the UV lamp by pulse-width-modulation to reduce UV power. The control algorithm decreases the current to a level (I.sub.kmin), increases the voltage amplitude (U) above the discharge voltage (U.sub.D) until a desired UV power level is reached. The pulse width (PW) is decreased with increasing voltage amplitude (U) until PW.sub.min is reached. The decrease in current and the increase in voltage generate an ineffective current-voltage-ratio in which excess current heats the cathode. An electronic ballast equipped with the algorithm and systems equipped with such ballasts are also disclosed.

A processor controlled induction RF fluorescent lamp, where the control processor runs a load control algorithm at least for switching the electrical load for connection to an external dimming device, the lamp comprising a vitreous envelope filled with an ionizable gas mixture; a power coupler comprising at least one winding of an electrical conductor; and an electronic ballast providing appropriate voltage and current to the power coupler.

A dimmer switch (110-x, 200, 400, 600, 700A, 700B, 1200) adapted to be coupled to an alternating current (AC) source and to a load so as to control an amount of power delivered from the AC source to the load, the dimmer switch may include: a triode for AC (TRIAC) (208, 408, 612) coupled between the AC source and the load, and which when triggered conducts to deliver a controlled amount of power from the AC source to the load for a corresponding half-cycle of one or more half cycles of the AC source. The dimmer switch may include first and second triggering circuits (606, 608) configured to trigger the TRIAC when charged after being enabled. One or more of the triggering circuits may be a self-balancing triggering circuit. The dimmer switch may further include a controller (412, 602, 1210) which selects and thereafter enables one or more of the first or second triggering circuits.

A control apparatus for a DC inverter electric motor comprising a control module and a controlled module is disclosed. The control module includes a phase-cut that continuously cut off a conduction angle of the AC power supply. The controlled module comprises a rectification circuit for rectifying the AC power supply after being cut off, a phase detection circuit for detecting the cut-off conduction angle, and a control unit for controlling the rotational speed or action of the motor according to the conduction angle that is detected by the phase detection circuit. The control apparatus makes use of the size of the conduction angle to act as control command and thus does not has the issue of reduced power factor. No complex or complicated circuits or wires have to be disposed and the functions can be achieved by making use of existing wiring. It is thus easy to install, cost-effective, and easy to maintain.