Abstract: A method for a digital subscriber line device to process dial string. The digital subscriber line device is coupled to a PSTN (public switched telephone network) and a VoIP network. First, a transmission is received by the digital subscriber line device. Then, the dial string of the transmission is compared with phone numbers stored in a PSTN digit map and in a VoIP digit map by a PSTN digit string processor and a VoIP digit string processor, respectively. The transmission is routed to the PSTN network when a phone number corresponding to the transmission is found in the PSTN digit map. The transmission is routed to the VoIP network when a phone number corresponding to the transmission is found in the VoIP digit map.

Abstract: A method for a broadband modem to process incoming calls. The broadband modem is coupled to a PSTN (public switched telephone network) and a VoIP network. First, an call is incoming by the broadband modem. Then, the broadband modem detects whether the incoming call is routed from the PSTN network or the VoIP network. When the incoming call is routed from the PSTN network, the broadband modem establishes a connection between a telephone coupled to the broadband modem and the PSTN network through a switch. When the incoming call is routed from the VoIP network, the broadband modem establishes a connection between the telephone and the VoIP network through the switch.

Abstract: A firmware upgrade method for a network device through a digital subscriber line. First, the network device transmits a request to a dynamic host configuration protocol server through a digital subscriber line. Then, information comprising a file server address and a query message are transmitted from the dynamic host configuration protocol server through the digital subscriber line to the network device in response to the request. The network device determines whether to upgrade the firmware of the network device according to the answer of the query message. If the network device determines to upgrade the firmware thereof, updated information about the firmware is downloaded from a file server corresponding to the file server address. Finally, the firmware of the digital subscriber line device is upgraded according to the updated information.

Abstract: A back lighting source module for a liquid crystal display comprises a pulse width modulation (PWM) controller for providing a pulse width signal to control output current of a lighting element. A half bridge converter includes two power transistors connected in series. An output is formed in a middle between the two power transistors. The output is controllable by the signal from the PWM controller to perform alternating opening and closing. A resonance circuit generates a sine-wave voltage to empower the lighting element. A feedback circuit includes a resistor. When a load varies, a voltage signal generated between two ends of the resistor of the feedback circuit timely changes a conductive time of the power transistors of the half bridge converter to complete regulation of current passing through the lighting element.

Abstract: An electronic stabilizer with single stage conversion includes a push-pull resonant stage, a synchronous pulse width modulation controller, and a converter. The push-pull resonant stage includes a high frequency transformer and transistors to form an alternating voltage-increasing loop that operates under self-activating oscillation, the high frequency transformer including a secondary winding for driving a lamp. The synchronous pulse width modulation controller samples signals from the lamp and feeds back to control a power input for the lamp. The converter includes transistors to form a dynamic resistance that allows current to flow in both directions. The converter includes an input end that is electrically connected to an output end of the synchronous pulse width modulation controller. The converter further includes an output end that is electrically connected in series to the secondary winding of the high frequency transformer and in series connection with the lamp.