Abstract: A redial system for a VoIP modem includes a subscriber line interface circuit (SLIC) for interfacing analog telephone signals from a telephone set to the VoIP modem and for generating redial signals to a public switched telephone network (PSTN), a first relay for connecting the telephone set with the PSTN or connecting the telephone set with the SLIC, a dummy load, a second relay connected between the PSTN and the dummy load for establishing or de-establishing a connection between the PSTN and the dummy load, a third relay connected between the first relay and the SLIC for establishing or de-establishing a connection between the first relay and the SLIC, and a control circuit for controlling the second and third relays to establish the connection between the PSTN and the dummy load and de-establish the connection between the first relay and the SLIC during the generation of the redial signals.

Abstract: A liquid crystal display (LCD) device has a housing acting as a conductor, a plurality of circuits, and at least a filter unit. Each circuit has a reference voltage terminal electrically connected to a reference voltage level. When the reference voltage terminal of each circuit is electrically connected to the housing, one filter unit is electrically connected between the housing and a ground terminal. When the housing is electrically connected to the ground terminal, a plurality of filter units are respectively connected between the housing and the reference voltage terminal of each circuit.

Abstract: A pulse dialing system for a VoIP modem includes a subscriber line interface circuit (SLIC) for interfacing analog telephone signals to digital signals, a relay for selectively connecting a telephone set with a public switched telephone network (PSTN) or with the SLIC, and a control means, coupled to the SLIC and to the relay, for receiving a digit of a dialed telephone number and for controlling the relay to connect the telephone set with the PSTN and with the SLIC alternatively for a number of cycle(s) equal to the digit of the dialed telephone number so as to generate pulse dialing signals to the PSTN.

Abstract: An inverter for igniting a discharge lamp comprises a transformer, a first switch transistor, a second switch transistor, a first snubber capacitor, a second snubber capacitor, a reset capacitor, and a control circuit. One of the source/drain of the first switch transistor is electrically coupled to the primary side of the transformer. One of the source/drain of the second switch transistor is electrically coupled to the primary side of the transformer. The first snubber capacitor is electrically coupled between the source and the drain of the first switch transistor. The second snubber capacitor is electrically coupled between the source and the drain of the second switch transistor. The reset capacitor is electrically coupled between the other of the source/drain of the first switch transistor and the other of the source/drain of the second switch transistor.

Abstract: A transformer reset circuit includes a first capacitor serially connected to a transformer winding, a rectifier connected in parallel with the first capacitor and the transformer winding, a second capacitor, an auxiliary switch connected in series with the second capacitor to form a series circuit connected in parallel with the rectifier, and a switch control circuit. The switch control circuit can turn on the main switch and turn off the auxiliary switch to release magnetizing energy stored in an inductor to charge the first capacitor. The auxiliary switch can be turned on and the main switch can be turned off to transfer the magnetizing energy stored in the inductor and the energy stored in the first capacitor to the second capacitor. After the energy stored in the inductor is dissipated, the second capacitor charges the inductor and the first capacitor to reverse the magnetic field in the inductor so as to reset the transformer.

Abstract: A multi-lamp system for driving a lamp set having a first lamp and a second lamp comprises a driving circuit for converting a DC signal to an AC signal, a transformer having a primary side coupled to the driving circuit and a secondary side for outputting the AC power, and a current balance circuit coupled to the low voltage terminal of the lamp set for balancing the current values flowing through the first lamp and the second lamp. The current balance circuit comprises a magnetic core, a first winding coupled to the first lamp and a second winding coupled to the second lamp. The first winding and the second winding are wound on the magnetic core and have the same coil number.

Abstract: This invention relates to a power supply that integrates a rectifier/filter's circuitry and a converter's circuitry with an inverter to reduce space occupied and increase power efficiency. The power supply includes: a rectifier/filter, a DC-DC converter and a DC-AC inverter. The rectifier/filter, connected to an alternating current (AC) input terminal, converts the input AC into a direct current (DC). The DC-DC converter and the DC-AC inverter are parallel to each other with one end concurrently connected to the rectifier/filter's output and the other end respectively outputting the desired powers. As such, DC-DC converter reduces the converted DC voltage to lower DC voltages to power all circuits except for the lamp and DC-AC inverter converts the converted DC voltage into higher AC voltage output to drive the lamp.

Abstract: A low voltage detecting circuit includes a first transistor having a first electrode electrically coupled to a reference voltage, a control electrode electrically coupled to the input power voltage, and a second electrode. The low voltage detecting circuit also has a second transistor having a first electrode electrically coupled to a logic high voltage, a control electrode electrically coupled to the second electrode of the first transistor, and a second electrode electrically coupled to a logic low voltage. When the input power voltage drops below the predetermined voltage, the voltage at the control electrode of the first transistor drops below the reference voltage to turn on the first transistor and consequently the second transistor so that a logic low signal is output from the first electrode of the second transistor.

Abstract: A transformer for an inverter circuit, comprising: a core module having a first core portion and a second core portion; a first bobbin having a first coiled portion and a first hollow portion for receiving the first core portion; a second bobbin substantially disposed parallel to the first bobbin, the second bobbin having a second coiled portion and a second hollow portion for receiving the second core portion; primary coils wound around the first coiled portion; and secondary coils wound around the second coiled portion.

Abstract: A DC to DC converter having a simplified logic circuit with both zero voltage switch function and synchronous rectification function, including a transformer having a primary coil and a second coil, a first half-bridge switch coupled to one end of the primary coil, a second half-bridge switch coupled to the other end of the primary coil, a first synchronous rectifier coupled to one end of the second coil, a second synchronous rectifier coupled to the other end of the second coil. The switching between the first half-bridge switch and the second half-bridge switch is made through the leakage inductance of the transformer and the open of the first synchronous rectifier and the second synchronous rectifier is made by the coil resistance of the transformer.

Abstract: This invention relates to a power supply that integrates a rectifier/filter's circuitry and a converter's circuitry with an inverter to reduce space occupied and increase power efficiency. The power supply includes: a rectifier/filter, a DC-DC converter and a DC-AC inverter. The rectifier/filter, connected to an alternating current (AC) input terminal, converts the input AC into a direct current (DC). The DC-DC converter and the DC-AC inverter are parallel to each other with one end concurrently connected to the rectifier/filter's output and the other end respectively outputting the desired powers. As such, DC-DC converter reduces the converted DC voltage to lower DC voltages to power all circuits except for the lamp and DC-AC inverter converts the converted DC voltage into higher AC voltage output to drive the lamp.

Abstract: A system for driving a plurality of lamps is disclosed to balance currents flowing through the lamps by means of impedance matching. According to the multi-lamp driving system of the present invention, a balancing controller is employed to match the impedance of each lamp path so as to regulate currents flowing through the lamps to be substantially the same.

Abstract: A transformer for an inverter circuit, comprising: a core module having a first core portion and a second core portion; a first bobbin having a first coiled portion and a first hollow portion for receiving the first core portion; a second bobbin substantially disposed parallel to the first bobbin, the second bobbin having a second coiled portion and a second hollow portion for receiving the second core portion; primary coils wound around the first coiled portion; and secondary coils wound around the second coiled portion.

Abstract: A multi-lamp system for driving a lamp set having a first lamp and a second lamp comprises a driving circuit for converting a DC signal to an AC signal, a transformer having a primary side coupled to the driving circuit and a secondary side for outputting the AC power, and a current balance circuit coupled to the low voltage terminal of the lamp set for balancing the current values flowing through the first lamp and the second lamp. The current balance circuit comprises a magnetic core, a first winding coupled to the first lamp and a second winding coupled to the second lamp. The first winding and the second winding are wound on the magnetic core and have the same coil number.

Abstract: The present invention relates to a driving system for multiple lamps, which comprises a plurality of lamps including one master lamp and at least one slave lamp, an inverter circuit for converting DC power to AC power to be supplied to said plurality of lamps, and at least one current balancing circuit having an impedance device coupled to each of the slave lamp, so that the equivalent impedance varies with the current values of said master lamp and each of said slave lamps to thereby balance the currents in said master slave lamps.