摘要:
A controller for dimming control of a switching power supply includes a phase angle measurement block and a drive logic block. The phase angle measurement block is to be coupled to receive an input sense signal. The phase angle measurement block generates a phase angle signal representative of a phase angle of an input voltage of the power supply in response to the input sense signal. The drive logic block is to be coupled to control switching of a switch included in the power supply. The drive logic block controls the switch in a closed loop dimming control when the phase angle is less than or equal to a phase threshold and in a open loop dimming control when the phase angle is greater than the phase threshold.
摘要:
A protection circuit for protecting a dimmer circuit controlling an inductive load including an imbalance detector for detecting an asymetrical operation in the load and circuit control means for causing the dimmer circuit to reduce a DC component in the load upon detection of the asymetrical operation. A load imbalance detector is also disclosed having a load DC component detector, a comparator and a signal generating means for generating means for generating a circuit shut down signal if the DC component exceeds a pre-set DC threshold.
摘要:
A switching arrangement for controlling the rpm constancy between idling and full power of universal motors in electric tools has a phase-shift control (IC) which, for setting the set value, is connected at an output via an adjusting resistor with a tap of a voltage divider, and whose trigger output controls an electronic power switch disposed in the electrical circuit of the motor. In order to obtain an optimal readjustment of the load in the entire provided rpm range by means of such a switching arrangement, it is provided that between the tap of the voltage divider and the one output of the phase-control circuit (IC) at least one further adjusting resistor is provided, with which a preferably electronic circuit device is switched in parallel, which is controlled from a point in the voltage divider.
摘要:
A phase switched power controller connects a load to a alternating current source for a proportion of each half cycle selected by the user. A first full wave rectifier is connected to the voltage source and produces an unfiltered full wave rectified output signal varying between zero and a predetermined peak. A low pass filtered full wave rectified signal is preferably obtained from a second full wave rectifier, the filtered voltage and unfiltered voltage being applied as inputs to a voltage comparator, the output of which triggers a timer. The timer determines the phase delay until a further pulse is triggered for activating a triac, applying power to the load during the remainder of each half cycle.
摘要:
A switching arrangement for full-wave power control comprising a triac (2), the control electrode of which is preceded by a trigger diode, the control voltage being taken from an RC section having at least one potentiometer (9), which effects a phase shift in the firing time as a function of the position of the potentiometer (9), is improved by the RC section (9, 10) being connected to a constant voltage source. This consists of two Z diodes (6) which are connectd in opposition and which are advantageously bridged by means of an adjustable voltage divider (7, 8), in such a manner that the RC section (9, 10) is connected to an adjustable part voltage. Instead of bridging the triac (2) for full drive, as usual, the trigger diode (11) is connected to a special bias resistor by means of a switch (13). According to a preferred embodiment, the resistors of the switching arrangement consists of a low-temperature thick-film paste printed on a hard paper board (see drawing relating to this).
摘要:
An integrated circuit includes: a pre-driver stage, coupled to an external supply voltage, for controlling the final driver stage; a final driver stage, coupled to the pre-driver stage and the external supply voltage, for providing an output voltage; a compensation circuit, coupled to the pre-driver stage, for providing a bias voltage to the pre-driver stage that compensates for variation in the external supply voltage, to control current through the pre-driver stage; and a bias circuit, coupled to the external supply voltage and the compensation circuit, for providing a bias voltage as an input to the compensation circuit.
摘要:
A switching regulator and method of regulating an ac input signal to provide an ac output signal, receiving the ac input signal, generating a reference signal, detecting the points when the ac input signal is zero and synchronising the reference signal to these points, performing a subtraction between the reference and ac input signals to obtain an error signal, dividing the error signal by the reference signal to obtain a fractional error, and producing a regulated ac output signal by modulating the ac input signal to correct for the fractional error. The switching regulator uses a modulating transistor and clamping diode for each half-cycle of the input signal.
摘要:
An appliance is provided with an improved power management system for controlling the total amount of current provided to at least a first load device of the appliance. The power management system is comprised of a microprocessor, an alternating current voltage source, a voltage regulating circuit, a clamping circuit, at least one load device, and a MOC and a triac for each of the at least two load devices. The clamping circuit outputs a fixed voltage of 5.7 volts during the positive portion of the ac cycle and a fixed voltage of −0.7 volts during the negative portion of the ac cycle. The fixed voltages are input to a microprocessor which utilizes these inputs to control the average voltage and the amount of time the current is turned on to each of the at least first and second load devices. A current sensing circuit is used to monitor the current to one of the at least two load devices to provide feedback to the microprocessor so that the microprocessor can adjust the average voltage and current to the at least two load devices so that the total current consumed does not exceed a pre-determined level.
摘要:
A photovoltaic power generation controller, in which minute power change is detected even with a low-resolution AD converter, thereby being capable of performing maximum power point tracking control with high accuracy, is provided. In the photovoltaic power generation controller of the invention, a control circuit 44 shifts switches 41 to respective output A sides of a voltage detector 8 and a current detector 9; gives a low-frequency ripple component to an operating voltage of a solar cell 1 while increasing modulation factor D by predetermined variation width d, to start maximum power point search from an open circuit voltage side; confirms a maximum power point passage when: an operating point oscillates in the vicinity of the maximum power point; and a power value, which is output by a power detector 43, after update of the modulation factor becomes smaller than a power value before update of the modulation factor; and switches the switches 41 to respective output sides of amplifiers 23 and 24 to continue the maximum power point tracking control.
摘要:
A dimmer circuit arrangement is disclosed including a second control circuit (40) for controlling the operation of a triac (50) for delivering current to a load (60), and a first control circuit (10) for controlling the operation of an IGBT power semiconductor switch (20) for controlling the rate of rise of load voltage. The first control circuit also controls the operation of the second control circuit.