Abstract: A projection apparatus and a light condensing module are provided. The light condensing module condenses and deflects an incident beam. The light condensing module includes a curving incident surface, a curving outgoing surface and a reflection surface. The curving incident surface receives the incident beam. The curving outgoing surface is disposed on a transmission path of the incident beam from the curving incident surface. The reflection surface is disposed on the transmission path of the incident beam, and located between the curving incident surface and the curving outgoing surface. A ray of the incident beam propagates through the curving incident surface along the optical axis of the curving incident surface, and emits out from the curving outgoing surface along a direction inclined to the optical axis of the curving outgoing surface.

Abstract: A UPS system includes one or more UPS units with identical or different capacities. A control circuit, used to control a DC/AC inverter of the UPS unit, includes a voltage feedback control circuit and a current feedforward control circuit. The voltage feedback control circuit is used to control the amplitude and the waveform of load voltage. The current feedforward control circuit is used to operate the DC/AC inverter of the UPS unit as a virtual fundamental resistor and a virtual harmonic resistor which are serially connected to an output terminal of the DC/AC inverter such that each UPS unit can be distributed to provide an output current according to the capacity ratio of the UPS system.

Abstract: The present invention discloses a thermal module for light source, which comprises a heat-conducting part and a heat-dissipating part engaged therewith. The heat-conducting part is provided with a heat-receiving portion to receive the heat generated by a light source, a joint portion to join with the heat-dissipating part. The heat-dissipating part is provided with a plurality of fin-shaped heat-dissipating sheets for heat dissipation and to join with the joint portion of the heat-conducting part.

Abstract: A UPS system includes one or more UPS units with identical or different capacities. A control circuit, used to control a DC/AC inverter of the UPS unit, includes a voltage feedback control circuit and a current feedforward control circuit. The voltage feedback control circuit is used to control the amplitude and the waveform of load voltage. The current feedforward control circuit is used to operate the DC/AC inverter of the UPS unit as a virtual fundamental resistor and a virtual harmonic resistor which are serially connected to an output terminal of the DC/AC inverter such that each UPS unit can be distributed to provide an output current according to the capacity ratio of the UPS system.