摘要:
Provided is a lamp ballast having a filament heating apparatus for gas discharge lamp, including a PFC converter for receiving an AC input voltage and converting the AC input voltage into a DC bus voltage; an inverter connected to an output end of the PFC converter for converting the DC bus voltage into an AC output voltage for driving gas discharge lamps; and a filament heating apparatus connected to the output end of the PFC converter. The filament heating apparatus includes an auxiliary heating circuit for converting the DC bus voltage into a heating power for pre-heating the filaments of the gas discharge lamps; and a control circuit connected to the inverter and the auxiliary heating circuit for generating an auxiliary voltage according to the heating power to activate the PFC converter. After the auxiliary heating circuit has been operating for a predetermined period of time, the auxiliary heating circuit is turned off first and then the inverter is turned on; or otherwise the inverter is turned on first and then the auxiliary heating circuit is turned off.
摘要:
A voltage regulation circuit includes a voltage conversion module, an LED driving module and a control module. The voltage conversion module is operable to receive and convert the first voltage to a second voltage. Each LED driving loop of the LED driving module has a current regulator and an LED string. The control module is operable to output a control signal according to the received input signal which reflects the current flowing through the LED driving module. The voltage conversion module regulates the second voltage according to the control signal, such that the regulated second voltage still keeps the brightness of the LED string of each LED driving loop unchanged.
摘要:
The electronic ballast includes: a square wave generator that includes a plurality of switching elements to convert a DC input voltage to an AC square wave output voltage; a transformer that includes a driving winding, a plurality of control windings, at least one inductive winding and at least one control driving circuit. The control windings controls the plurality of switching elements to turn on alternately; a resonant circuit that constitutes a resonant loop together with the driving winding is electrically connected with an output terminal of the square wave generator to drive the light emitting element. The control driving circuit is connected with two terminals of the inductive winding in parallel and receives a control signal to control a voltage across the inductive winding so as to control conducting time of at least one of the switching elements.
摘要:
Provided is a lamp ballast having a filament heating apparatus for gas discharge lamp, including a PFC converter for receiving an AC input voltage and converting the AC input voltage into a DC bus voltage; an inverter connected to an output end of the PFC converter for converting the DC bus voltage into an AC output voltage for driving gas discharge lamps; and a filament heating apparatus connected to the output end of the PFC converter. The filament heating apparatus includes an auxiliary heating circuit for converting the DC bus voltage into a heating power for pre-heating the filaments of the gas discharge lamps; and a control circuit connected to the inverter and the auxiliary heating circuit for generating an auxiliary voltage according to the heating power to activate the PFC converter. After the auxiliary heating circuit has been operating for a predetermined period of time, the auxiliary heating circuit is turned off first and then the inverter is turned on; or otherwise the inverter is turned on first and then the auxiliary heating circuit is turned off.
摘要:
An all-in-one computer includes a monitor, a motherboard, a power supply, and a support mechanism supporting the monitor. The support mechanism includes a base, and a support stand fixed on the base and connected to the monitor. The support stand defines a cavity to receive the motherboard and the power supply. The motherboard and the power supply are electrically connected to the monitor.
摘要:
A connector assembly includes a connector, a card reader, and a housing. The housing includes a top cover and a bottom cover. The top cover includes a first receiving portion for the connector and a second receiving portion for the card reader. The top cover includes a baseboard fixed on the first receiving portion and a shutter moveably positioned on the second receiving portion covering the card reader.
摘要:
In a decoder for decoding a low density parity check (LDPC) code suitable for decoding multi-rated LDPC codes, a method is provided. The method comprises the steps of: providing a memory for the decoding with the memory dependent on a parity check matrix H with maximum number of “1”s; using a number of column updating units, updating columns parallely and simultaneously producing messages; and using a number of row updating units, updating rows parallely and simultaneously producing messages. Whereby an improved architecture in a logic and the memory is provided such that an improved throughput, power consumption, and memory area is achieved.
摘要:
Described is an one bit matched filter for generating a sequences of correlations between a signal bit stream and a sample stream of n sample bits. The n sample bits are arranged in a rang of n bit positions n, n-1, . . . , 2, 1. Among the n sample bits, m boundary positions are defined based on the bit pattern of the sample stream, where m
摘要:
A retention assembly for securing a hard disk to a frame of an electronic device, the retention assembly includes a bracket and a connector. The bracket is fixed to the hard disk. One of the frame and the bracket defining a guide groove, the other one forming a slide rail slidably received in the guide groove. The connector fixed to the frame and adjacent to the guide groove or the slide rail. The hard disk is electrically connected or disconnected to the connector by sliding the bracket along the guide groove or the slide rail.
摘要:
A retention assembly for securing a optical disc drive (ODD) to a main frame of an electronic device includes a bracket and a connector. The bracket is fixed to the ODD. One of the main frame and the bracket defines a guide groove, and the other includes a slide rail movably received in the guide groove. The connector is fixed to the main frame and adjacent to the guide groove or the slide rail. The ODD is aligned to electrically connect to the connector by the at least one guide groove or the at least one slide rail.