An inverter producing an alternating current from a direct current source has a primary stage coupled to the direct current source having a step-up transformer, a first switching circuit coupling the direct current to the transformer primary and a rectifier coupled to a secondary of the transformer for producing a DC voltage; a controller for the first switching circuit providing pulse drive signals to control switches of the first switching circuit to cause current to flow in the transformer primary and induce an alternating current in the transformer secondary; a secondary stage receiving the DC voltage having a second switching circuit and a controller for the second switching circuit for generating control signals to cause current through the second switching circuit to flow in alternate directions thorough the load. In one embodiment the alternating current period is divided into time slices and the switches of the first switching circuit are duty cycle modulated at different duty cycles in each time slice. A second embodiment switches series-connected primary windings of a multi-tap transformer.

An inverter producing an alternating current from a direct current source has a primary stage coupled to the direct current source having a step-up transformer, a first switching circuit coupling the direct current to the transformer primary and a rectifier coupled to a secondary of the transformer for producing a DC voltage; a controller for the first switching circuit providing pulse drive signals to control switches of the first switching circuit to cause current to flow in the transformer primary and induce an alternating current in the transformer secondary; a secondary stage receiving the DC voltage having a second switching circuit and a controller for the second switching circuit for generating control signals to cause current through the second switching circuit to flow in alternate directions thorough the load. In one embodiment the alternating current period is divided into time slices and the switches of the first switching circuit are duty cycle modulated at different duty cycles in each time slice. A second embodiment switches series-connected primary windings of a multi-tap transformer.

The present disclosure provides a driving system for a semiconductor light source and a semiconductor lighting device. The driving system comprises: a transformer, the transformer comprising a first coil (201) and a second coil (202) mutually coupled to each other, the second coil (202) being used for receiving an input voltage; a switching device which is connected in series to the second coil (202) and used for controlling energy storage and energy release of the second coil (202); and an outputting device which is connected in parallel to the second coil (202) and used for supplying power to the semiconductor light source. An induced signal is generated on the first coil of the transformer due to a coupling effect between the first coil and the second coil and is used for controlling the switching-on and switching-off of the switching device.

A universal load control module may include a power supply that operates over a wide voltage range, a microcontroller, and one or more functional control blocks. A functional control block may include a dimmer circuit for controlling a lighting load that provides reverse phase cut mode dimming, forward phase cut mode dimming, and hybrid phase cut mode dimming, as well as thermal protection. One or more universal control modules may be housed in a cabinet that include a cabinet control module. The cabinet may include additional thermal protection measures.