摘要:
The invention relates to a resistor network (2) such as a resistor ladder network, comprising at least a resistor body (4) which is provided with at least a column (6) of taps (8) situated between a first tap and a second tap, wherein, in use, at least two taps can be connected with respective first and second sources of reference input potentials, and wherein each tap of the at least one column of taps can be used for outputting an output potential via a contact area which is connected with the concerning tap, wherein the resistor body (4) comprises a multiple of resistor sub-bodies (5), wherein each resistor sub-body (5) is connected with a column (6) of taps (8), and wherein the only electrical connections between the resistor sub-bodies (5) are established by electrical connections via taps (8) connected with the resistor sub-bodies (5). Furthermore the invention relates to a method for manufacturing a resistor network (2) such as a resistor ladder network.
摘要:
The invention relates to a resistor network (2) such as a resistor ladder network, comprising at least a resistor body (4) which is provided with at least a column (6) of taps (8) situated between a first tap and a second tap, wherein, in use, at least two taps can be connected with respective first and second sources of reference input potentials, and wherein each tap of the at least one column of taps can be used for outputting an output potential via a contact area which is connected with the concerning tap, wherein the resistor body (4) comprises a multiple of resistor sub-bodies (5), wherein each resistor sub-body (5) is connected with a column (6) of taps (8), and wherein the only electrical connections between the resistor sub-bodies (5) are established by electrical connections via taps (8) connected with the resistor sub-bodies (5). Furthermore the invention relates to a method for manufacturing a resistor network (2) such as a resistor ladder network.
摘要:
A method is disclosed of controlling a LED, comprising driving the LED with a DC current for a first time, interrupting the DC current for a second time such that the first time and the second time sum to a period, determining at least one characteristic of the LED while the DC current is interrupted, and controlling the DC current during a subsequent period in dependence on the at least one characteristic. The invention thus benefits from the simplicity of DC operation. By operating at the LED in a DC mode, rather than say in a PWM mode, the requirement to be able to adjust the duty cycle is avoided. By including interruptions to the DC current, it is possible to utilize the LED itself to act as a sensor in order to determine a characteristic of the LED. The need for additional sensors is thereby avoided.
摘要:
Consistent with an example embodiment, there is a method of controlling a synchronous rectifier having an input signal having oscillations therein and a switch which is switchable between an open state and a closed state. The method comprises filtering the input signal to produce a filtered signal, comparing the filtered signal with a reference value, and opening the switch in response to the comparison, in which the filtering is active filtering.The active filtering may be based on determination of the peaks (positive and/or negative) of the signal, either directly, including a quarter period offset, or including decay—or a combination of the above; alternatively, the active filtering may be based on the a smoothing functions such as a switched low-pass filter or a short time integrator.
摘要:
The present invention relates to an electronic device for driving a light emitting diode, which includes a switch (Ts) being adapted to switch a switch-mode power converter, and controlling means (CNTL) being adapted for controlling the switch (Ts) in response to a sensing value (Vs) indicative of a current of the switch-mode power converter and for controlling by the switch (Ts) the output voltage of the switched power converter and a current (Tout) through the light emitting diode.
摘要:
A power supply unit is provided which comprises an AC/DC conversion unit with an input to which an input voltage is coupled and an output to which a DC bus voltage is coupled. The power supply unit furthermore comprises a DC bus capacitor which is coupled to the output of the AC/DC conversion unit. The power supply unit furthermore comprises at least one sub-power supply unit receiving the DC bus voltage as input for providing at least one power supply. The power supply of the at least one sub-power supply unit or part of the load is at least reduced or switched off if the input voltage falls below a predetermined threshold value.
摘要:
A switched mode power converter is disclosed, together with a method for operating the same. The power converter is adapted to be operable in the boundary conduction mode, and operation is interruptible in the absence of any load requirement.
摘要:
Method and apparatus for controlling the rotation velocity of an optical disc in a wide range of velocities, including low velocities. In a first range of velocities, a first sensor, for example an EMF sensor, is used to control the commutation moments of a turntable motor. For velocities outside the first range, a periodic control signal based on a periodic second signal generated by a second sensor and a mapping between the first and second periodic signal are used. The method and the apparatus are suitable for LightScribe™ applications.
摘要:
The invention provides a LED arrangement including a LED string of a series arrangement of LED segments. A LED segment includes a single LED or a series arrangement of LEDs. A switching element (12, 22) is arranged in parallel with each corresponding LED segment (10, 20) of the LED string, for controlling a current (52, 62) through the LED segment (10, 20). A capacitor (13, 23) is arranged in parallel with each corresponding LED segment (10, 20) in order to prevent the occurrence of possibly harmful current spikes while switching one or more LED segments. The LED arrangement may also include a switched-mode power supply (2001). The invention further provides a LED assembly. A plurality of such LED assemblies assembles easily into a LED arrangement according to the invention.
摘要:
The invention is directed to a method for controlling a deceleration process of a DC motor (20), wherein the DC motor (20) is driven by a bridge driver (18) coupled to a power supply (12) intended to provide a supply voltage VDD at a power supply output (14), the method comprising the following steps: applying a deceleration PWM signal to the bridge driver (18) for decelerating the DC motor (20), and controlling the bridge driver (18) such that a motor-induced back current is reduced, if the voltage at the power supply output (14) exceeds a first voltage threshold which is higher than VDD. In accordance with the invention the method comprises the following step: if the voltage at the power supply output (14) falls below a second voltage threshold which is lower than the first voltage threshold, terminating controlling the bridge driver (18) such that the motor-induced back current is reduced. The invention is also directed to a controller (10) for controlling a deceleration process of a DC motor (20) which is driven by a bridge driver (18) coupled to a power supply (12) intended to provide a supply voltage VDD at a power supply output (14), the controller (10) comprising: means (22) for applying a deceleration PWM signal to the bridge driver for decelerating the DC motor, and means (24, 26, 28; 24, 30) for controlling the bridge driver (18) such that the motor-induced back current is reduced, if the voltage at the power supply output (14) exceeds a first voltage threshold which is higher than VDD. In accordance with the invention the means for controlling the bridge driver (18) such that the motor-induced back current is reduced are adapted to terminate controlling the bridge driver (18) such that the motor-induced back current is reduced, if the voltage at the power supply output (14) falls below a second voltage threshold which is lower than the first voltage threshold.