摘要:
A television receiver has a switched mode power supply controller, which may be deflection synchronized, which produces pulses in a power transformer. To power the controller during startup, before the internal power supply has started, a storage capacitor on the power supply input of the controller is coupled through a current limiting resistance to a rectified voltage from the AC mains so as to charge the storage capacitor during first polarity phases of the AC mains. The current limiting resistance includes a positive temperature coefficient (PTC) element which increases its impedance as it heats, to reduce power dissipation after initial connection of the television receiver to AC mains. In addition, a diode is coupled in a current path to the storage capacitor to charge the capacitor to the same polarity during opposite polarity phases of the AC mains. The two paths for charging the capacitor allow a relatively smaller value for the current limiting resistance, which remains coupled to the storage capacitor, and provides sufficient power to the controller without undue power dissipation over a wide range of power mains voltages.
摘要:
The invention relates to a method for switching a multimedia source and multimedia sink from an operating mode to a standby mode, and a method for switching a multimedia source and multimedia sink from a standby mode to an operating mode. When the consumer device comprises two distributed boxes, such as a TV in which the display (multimedia sink) is separated from the processing unit (multimedia source) via a cable, then meeting the green rules for standby power becomes more complicated. The power consumption of processing unit and display unit should be minimal in standby mode. The methods of the invention provide for synchronizing the power states of both units, such that only the relevant parts remain active. The method is applicable on configurations where a DisplayPort link is used between a multimedia source, such as a set-top box, and a multimedia sink, such as a display. The invention provides a reduction in overall power consumption, while still complying with the Display-Port configuration and operation standard. In an embodiment of the invention, the source and sink are configured to allow communication of standby and wake-up requests/commands when the transmitter and receiver for the auxiliary channel are powered down. The invention also provides embodiments where the switching to and from standby of the source is triggered by user
摘要:
The processing unit (1) for generating a scan velocity modulation signal (DS) has an input for receiving a video signal (VS) and an output for supplying a modulation signal (DS). The unit (1) comprises a series connection of, successively, a coring circuit (C), a differentiator (D), and a limiter (L). The display device (16) comprises a cathode ray tube (10) and the processing unit (1).
摘要:
A controller, which is normally used for controlling different modes is used for circuit protection. The suipply voltage and control signals from the switched mode power supply to the controller are modified when a short circuit occurs. In response thereto, the controller switches "off" a mode-control signal and the switched mode power supply operates in standby mode.
摘要:
A method for fabricating a bi-polar plate of a fuel cell and the bi-polar plate thereof are presented. A graphite film is formed first. Next, a polymeric material added with electrically conductive powder is coated on a surface of a metal substrate. The graphite film is disposed on the polymeric material and the polymeric material is hardened to form an adhesive layer, such that the graphite film is attached on the surface of the metal substrate.
摘要:
Due to low output voltage during flyback mode of start phase the secondary current cannot be fully discharged in time. The current buildup will eventually damage the output transistor if the current is not limited. In order to prevent the current build up during start phase, the storage time of the output transistor of the SMPS has to be reduced. During the startup phase a negative bias capacitor is not fully charged. Thereby the base of an output transistor is not biased sufficiently when the transistor is switched off. So the transistor could not operate safely if the collector voltage is higher than Vceo. It is the object to keep charges, which are stored on the capacitor during startup phase and to reduce discharging of the capacitor. According to this invention means are provided between the base and the emitter of the output transistor. It is preferred that said means are realised by a resistor and a diode, connected in series.
摘要:
A television receiver has a switched mode power supply controller, which may be deflection synchronized, which produces pulses in a power transformer. To power the controller during startup, before the internal power supply has started, a storage capacitor on the power supply input of the controller is coupled through a current limiting resistance to a rectified voltage from the AC mains so as to charge the storage capacitor during first polarity phases of the AC mains. The current limiting resistance includes a positive temperature coefficient (PTC) element which increases its impedance as it heats, to reduce power dissipation after initial connection of the television receiver to AC mains. In addition, a diode is coupled in a current path to the storage capacitor to charge the capacitor to the same polarity as during opposite polarity phases of the AC mains. The two paths for charging the capacitor allow a relatively smaller value for the current limiting resistance, which remains coupled to the storage capacitor, and provides sufficient power to the controller without undue power dissipation over a wide range of power mains voltages.