Abstract: The present invention relates to a platform door control apparatus based on a double 2-vote-2 architecture, including a security communication and logic processing module, a driver collection module, and a maintenance module, the security communication and logic processing module is separately connected to the driver collection module and the maintenance module, and both the security communication and logic processing module and the driver collection module are devices using the double 2-vote-2 architecture. Compared with the prior art, the present invention has the following advantages of effectively improving linkage efficiency of a signal system and a platform door system, and the like.

Abstract: A power switch device driver with energy recovery is discussed. The power switch device adopts four switches and one inductor with appropriate control to insure the switching speed and save the power loss.

Abstract: Disclosed are an optical fiber time domain reflectometer (OTDR), a test system, test method, and a storage medium. The OTDR comprises: an input end for receiving an input service optical signal; a first filter connected with the input end and for filtering an interference signal with a wavelength equal to a test wavelength of the OTDR in the service optical signal; a wavelength division multiplexing WDM device having a reflection end, a transmission end and an output end; and an OTDR basic unit connected with the transmission end and used for emitting an OTDR signal equal to a test wavelength and receiving a return signal of the OTDR signal, wherein the output end of the WDM device is for outputting a filtered service optical signal received from the reflection end, outputting the OTDR signal received from the transmission end, and receiving the return signal returned from the optical fiber.

Abstract: An optical amplifier assembly and a detection method capable of dynamically performing optical time-domain reflection detection. The detection method comprises obtaining signal light intensity detection signals from a first and second photodetectors and sending a control signal to an L-band Raman pump when the signal light intensity in the second photodetector is lower than a first preset threshold, so that the L-band Raman pump enters into an optical time-domain reflection detection mode; sending a control signal to the L-band Raman pump when the signal light intensity in the second photodetector is greater than or equal the first preset threshold, so that the L-band Raman pump enters into an L-Band Raman optical fiber amplifier operation mode.

Abstract: A power switch device driver with energy recovery is discussed. The power switch device adopts four switches and one inductor with appropriate control to insure the switching speed and save the power loss.

Abstract: An optical amplifier assembly and a detection method capable of dynamically performing optical time-domain reflection detection. The detection method comprises obtaining signal light intensity detection signals from a first and second photodetectors and sending a control signal to an L-band Raman pump when it is determined that the signal light intensity in the second photodetector is lower than a first preset threshold, so that the L-band Raman pump enters into an optical time-domain reflection detection mode; sending a control signal to the L-band Raman pump when the signal light intensity in the second photodetector is greater than or equal the first preset threshold, so that the L-band Raman pump enters into an L-Band Raman optical fiber amplifier operation mode.

Abstract: A LED driver comprising: a power switch; a transformer comprising a primary winding coupled to the power switch, a secondary winding and a third winding; a current sense circuit configured to sense a current flowing through the power switch and generates a current sense signal; a zero cross detecting circuit configured to detect a current flowing through the secondary winding, and generates a zero cross detecting signal; a compensation circuit configured to compensate the current sense signal based on the current flowing through the third winding; a control circuit configured to receive the compensated current sense signal and the zero cross detecting signal, and wherein the control circuit generates a control signal to control the power switch.

Abstract: Embodiments of LED driver circuits and the associated methods are disclosed herein. In one embodiment, the LED driver circuit comprises a switch-mode converter, a controller, a feedback circuit, and a gating circuit. The feedback circuit includes a current balance circuit. The gating circuit is responsive to both a current feedback signal and a voltage feedback signal and is configured to select one of them as the feedback signal.

Abstract: A power supply system having a voltage source; a load; a filter circuit to filter the voltage provided by the voltage source and to output a filtered voltage; and a follower circuit configured to generate an output signal at an output of the follower circuit based on the filtered voltage, and further wherein the output of the follower circuit is coupled to the load.

Abstract: A controller used in a light emitting element driving circuit, wherein the light emitting element driving circuit has a power converter configured to provide an output current for the light emitting element. The controller has a dimming processing unit and a current control unit. The dimming processing unit is configured to receive a first dimming signal with a first duty cycle and a second dimming signal with a second duty cycle, and to generate a second dimming processing signal relative to the product of the first duty cycle and the second duty cycle. The current control unit is coupled between the dimming processing unit and the power converter, and is configured to generate a control signal for the power converter based on the second dimming processing signal and a feedback signal indicating the output current.

Abstract: A LED driver comprising: a power switch; a transformer comprising a primary winding coupled to the power switch, a secondary winding and a third winding; a current sense circuit configured to sense a current flowing through the power switch and generates a current sense signal; a zero cross detecting circuit configured to detect a current flowing through the secondary winding, and generates a zero cross detecting signal; a compensation circuit configured to compensate the current sense signal based on the current flowing through the third winding; a control circuit configured to receive the compensated current sense signal and the zero cross detecting signal, and wherein the control circuit generates a control signal to control the power switch.

Abstract: A current balance scheme for driving LED strings is disclosed. A power supply unit provides a driving voltage to drive a plurality of LED strings. A feedback selector is configured to select a minimum feedback signal indicative of the driving voltage to the power supply unit for regulating the driving voltage. Based on the minimum feedback signal, the driving voltage gets a minimum value to sufficiently drive the plurality of LED strings. A protection circuit is configured to protect the current balance circuit from high voltage especially when there is a shorted LED string.

Abstract: Embodiments of LED driver circuits and the associated methods are disclosed herein. In one embodiment, the LED driver circuit comprises a switch-mode converter, a controller, a feedback circuit, and a gating circuit. The feedback circuit includes a current balance circuit. The gating circuit is responsive to both a current feedback signal and a voltage feedback signal and is configured to select one of them as the feedback signal.