摘要:
Resonant gate driver circuits provide for efficient switching of, for example, a MOSFET. However, often an operation of the resonant gate driver circuit does not allow for an application where high switching frequencies are required. According to the present invention, a pre-charging of the inductor of the resonant gate driver circuit is performed. This allows for a highly efficient and fast operation of the MOSFETs.
摘要:
The invention describes a method of transmitting information between an information transmitter and an information receiver, the potential difference of which moves in cycles between a minimum value and a maximum value and is situated at the minimum value for regular intervals; having the steps: provision of information over the time interval or determining the time interval in which the potential difference between information transmitter and information receiver assumes its minimum value; closing of a switching means of the information transmitter in relation to an information memory assigned to the information receiver, only within the time interval; and transmission and storage of the information in the information memory.
摘要:
Usually, power supplies are not capable of switching off part of the outputs of a main power supply during stand-by. Due to this, stand-by power supplies are used in addition to operation power supplies. Consistent with an example embodiment, a forward converter is provided, including switches in the rectifier circuit thereof. Due to this, the rectifier circuits may be selectively switched on and off. Advantageously, this may allow that the main outputs of such a forward converter are switched off while on stand-by.
摘要:
Recently, the use of class-D audio amplifiers has become more and more widespread. In contrast to the generally employed class-AB linear amplification technology, class-D allows for improved efficiency. However, the class-D principle is known for its poor distortion characteristics. According to the present invention a digital amplifier (18) is provided for converting an audio signal to a power output, comprising a ripple suppression circuit (16) for suppressing voltage ripples in a supply voltage supplied to the bridge circuit with (6) at least one pair of switches. The ripple suppression circuit (16) suppresses ripples in the supply voltage supplied to a switch in the bridge circuit (6), which has been found to cause a major part of the distortions in the output signal of the digital amplifier (18).
摘要:
A control unit (2) of a remote control receiver sets the forward or reverse direction operating mode of the photodiode (1) as a function of the useful signal level of its output signal, and to be precise, during standby, the photovoltaic operating mode (forward mode), since in this mode no external bias current is required. If the useful signal level of the photodiode (1) exceeds a predefined threshold, the reverse mode is set, and this brings with it a higher sensitivity. A series circuit (A) of a number of identical photodiodes DA1 DAn the forward mode allows the realization of a controlled current source (6) having a transistor (T), since the permissible diode voltage (Ud) of the overall arrangement may have n times the value of the operating voltage of an individual photodiode. Thus at the same time the voltage across the individual diodes can be set to a very low value and a favorable operating range for the current source can be set. The possible sensitivity of the receiver module having diodes in this operating mode can thereby be considerably increased.
摘要:
In a switching DC converter with a resonant circuit output stage, the energy remaining in the resonant circuit for switching the switches of the converter in an inductive mode of operation is used to control the phase of switching. The turn-on phase of each switch is controlled to assure zero voltage switching, and the turn-off phase of each switch is controlled to assure that the resonant circuit has sufficient energy to provide this zero voltage switching.
摘要:
The invention relates to a converter comprising switching elements for chopping a direct voltage, in which turn-on phases of the switching elements alternate with one another, and comprising a circuit arrangement with resonant circuit elements processing the chopped direct voltage and serving for the supply of an output voltage. To improve such a converter in such a way that zero voltage switching (ZVS) can be ensured in an extended range of converter operations with possibly inexpensive converter modifications, it is proposed that the length of the dead-time phases, which are present between two consecutive turn-on phases and during which the switching elements are turned off, is automatically adapted so that switching losses, which occur particularly when the switching elements are turned on, can be minimized.
摘要:
A light generating device (1) is provided with at least a voltage input (21) adapted for receiving a variable voltage, at least three LED circuits (10), coupled with said voltage input (21), wherein each LED circuit (10) comprises a LED unit (14) and controllable current regulator (15) to control the current through said LED circuit (10). The light generating device (1) further comprises a controllable switch matrix (30) comprising a plurality of switches (25, 26, 27), said switch matrix (30) is configured to operate in at least three different switching modes and a controller (50), connected at least with said switch matrix (30), configured to determine said variable operating voltage and to control the switching mode of said switch matrix (30) in dependence of the determined operating voltage. To provide an efficient operation of such device (1) with a variable operating voltage, such as an AC voltage, in a first switching mode, said LED units (10) are connected parallel to each other, in a second switching mode, at least two of said LED units (10) are connected in series and in a third switching mode, said LED units 10 are connected in series with each other.
摘要:
The invention relates to a lighting device that may particularly be used as an LCD backlight and that comprises an array of light emitters (11.1, 11.2) which are optionally separated by optical barriers (13). The light emitters (11.1, 11.2) may particularly be realized by groups of LEDs (12.1, 12.2) of different colors, for example red, green and blue. Local control units (16), driving units (15.1, 15.2), and sensor units (14) are provided to control the individual light output of the light emitters, wherein at least one of these components is shared by two or more light emitters (11.1, 11.2).
摘要:
The present invention relates to a driver device (40; 50; 60) and a corresponding driving method for driving a load (12), in particular an LED unit (12) including one or more LEDs, said driver device comprising a power input unit (14) for receiving an input voltage (V10) from an external power supply (18) and for providing a rectified supply voltage (V12), a controllable resistor (48) for providing a load current (I L) to power the load (12), a frequency filter (42) connected to the power input unit (14) for providing a voltage (V18) to the load (12), wherein the frequency filter (42) is partially coupled in parallel to the load (12) and connected to the controllable resistor (48) to provide a substantially constant electrical power to the load (12).