Patent application number | Description | Published |
20100172157 | SWITCHING POWER SUPPLY DEVICE AND SWITCHING POWER SUPPLY CONTROL CIRCUIT - The invention provides a switching power supply device which can detect a light load state on a pulse-by-pulse basis without worsening power efficiency. In a synchronous control circuit, for each timing of the turning-on of main switching elements, the delay time Tdif of the conduction timing of internal diodes Ds determined according to the magnitude of the load LD is detected by a comparator, a reference time pulse Tsrs having a prescribed time width is generated by a load judgment circuit, and the logical product of the two is generated by an AND circuit. By this means, the load is regarded as being a light load when the delay time Tdif is longer than the reference time pulse Tsrs, and the synchronous rectification MOSFETs Qs are not turned on. | 07-08-2010 |
20110109281 | POWER FACTOR CORRECTION TYPE SWITCHING POWER SUPPLY UNIT - A multiplier multiplies a current signal of an Iy generator and a voltage signal from a Vx generator corresponding to a divided voltage value of an output voltage of a full-wave rectifier. The result of the multiplication is output as a current reference signal to the non-inversion input terminal of a current error amplifier. A current peak waveform generator circuit generates an envelope waveform of peak values of an inductor current. An Iz generator, when the envelope waveform exceeds a first threshold value smaller than a third threshold value set in an overcurrent protection circuit, curbs the inductor current by adjusting the size of a current signal output to the multiplier, and reducing the current reference signal. | 05-12-2011 |
20110122664 | POWER FACTOR CORRECTION TYPE SWITCHING POWER SUPPLY UNIT - A soft-stop overvoltage protection circuit, into which a soft-stop overvoltage detection voltage proportional to a direct current output voltage is input, reduces the output of a multiplier in accordance with the soft-stop overvoltage detection voltage when the soft-stop overvoltage detection voltage exceeds a first threshold value. An overvoltage protection circuit, a second threshold value higher than the first threshold value being set, compulsorily turns off a switching element by outputting an overvoltage detection signal when the soft-stop overvoltage detection voltage exceeds the second threshold value. The soft-stop overvoltage protection circuit compulsorily increases the output of a voltage error amplifier circuit on the output voltage decreasing. When the output of the voltage error amplifier circuit increases suddenly, and the output voltage rises excessively, the soft-stop overvoltage protection circuit decreases the output of the multiplier, thus curbing the rise of the output voltage. | 05-26-2011 |
20110141631 | POWER FACTOR CORRECTION TYPE SWITCHING POWER SUPPLY UNIT - A power factor correction type switching power supply unit can change reference values of an overcurrent limit at an optimum timing at a time of an overcurrent protection of a step-up type converter, so that no sudden change occurs in an inductor current. A detection level selection circuit selects one of first and second threshold values with a selection signal, and outputs it as an overcurrent detection level to an overcurrent detection circuit. An input voltage monitoring circuit determines the selection signal in such a way that the larger of two threshold values is selected when an alternating current input voltage exceeds a first reference voltage, and the smaller threshold value is selected when the alternating current input voltage does not exceed a second reference voltage, and outputs the selection signal to the detection level selection circuit at a timing at which the alternating current input voltage approaches a zero. | 06-16-2011 |
20120113689 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device that includes a feedback terminal to which a feedback signal according to a load state is input, and a comparator which compares a terminal voltage of the feedback terminal with a reference voltage and determines whether the load state is a normal load state or a light load state. The switching power supply device also includes pull-up resistors which are connected to the feedback terminal, a switch element which switches resistance values of the pull-up resistors according to the change of the load state, and a switch element which switches the resistance values of the pull-up resistors according to whether the input voltage is high or low. | 05-10-2012 |
20120250362 | SWITCHING REGULATOR CONTROL CIRCUIT - In a switching regulator control circuit according to aspects of the invention, a drain current is converted to a voltage Vis with a resistance. The voltage is delivered to a multiplication circuit. The multiplication circuit generates and outputs a voltage that is a product signal of the voltage and a voltage that is proportional to a duty factor. A comparator circuit compares the voltage with an error signal delivered to the other comparison input terminal of the comparator. When the voltage has reached the error voltage, the comparator delivers a turn-off instruction through an OR circuit to a terminal of a flip-flop. | 10-04-2012 |
20130010502 | SWITCHING REGULATOR AND CONTROL DEVICE THEREOF - A switching regulator related to aspects of the invention can include an auxiliary winding for monitoring the voltage across the primary winding of a transformer, a differentiation detecting circuit that detects the timing of reversal start or reversal end of the signal detected by the auxiliary winding and a dead time adjusting circuit that receives a signal to trigger turn OFF of a switch or a switch and, after passing a predetermined delay time from the detection of the signal, generates a signal to trigger turn ON of the switch or the switch. The differentiation detecting circuit can confirm current transfer between body diodes. The dead time adjusting circuit can adjust a dead time to deliver the signal after a predetermined time from the confirmation of the current transfer. In some aspects of the invention, occurrence of hard switching and short-circuit current can be suppressed. | 01-10-2013 |
20130127432 | SWITCHING POWER SUPPLY DEVICE - An object of the present invention is to achieve the reduction of EMI, the improvement of conversion efficiency, and simplification of the input filter. Provided is a switching power supply device that comprises: a chopper circuit that turns on/off the passage of a current to an inductor by means of a switching element; and a switching control circuit that switches the switching element so that an input voltage and an input current have the same phase and a similar shape. The switching control circuit is configured to switch the switching element at a switching frequency that is proportional to an input voltage dependent term of a formula that expresses a third harmonic component of ripples of the current flowing to the inductor. | 05-23-2013 |
20130148386 | SWITCHING REGULATOR - A switching regulator can include a transformer having a primary winding and a secondary winding, a switching circuit including a switching element that is connected in series to the primary winding, the series-connected circuit of the switching element and the primary winding being connected in parallel to a DC power supply and a rectifying circuit connected to the secondary winding. The switching regulator can also include a control circuit to control switching of the switching element to generate DC output voltage from the DC power supply, the DC output voltage being insulated from the DC power supply, an output voltage detecting circuit including a photo-coupler for insulated detection of the DC output voltage, the photo-coupler having a photo-transistor and a load quantity detector for detecting a state in which power consumption in the load connected to the DC output has reached a predetermined value. | 06-13-2013 |
20130194827 | SWITCHING POWER SUPPLY - A switching power supply of certain aspects of the invention includes a minimum dead time generating circuit that generates a minimum dead time from an OFF timing of an ON pulse detected from the voltage across an auxiliary winding of the transformer by a differentiating circuit. An ON width-determining means of a voltage control oscillator is started, after this minimum dead time, into operation to determine the ON width of the semiconductor switch. | 08-01-2013 |
20130294125 | CONTROL CIRCUIT OF POWER SUPPLY SYSTEM - Aspects of the invention provide an error amplifier that can compare a feedback voltage of an output voltage with a reference voltage to produce a resulting error signal in cooperation with a phase compensating circuit. In some aspects of the invention, an AC detecting circuit makes a decision as to whether a detected input voltage signal is that of a 100 Vac system or that of a 200 Vac system to change the gain of the error amplifier according to the result of the decision. When the voltage signal Vis is lower than the threshold voltage established beforehand, for making the transient response speed of the phase compensating circuit faster, the AC detecting circuit increases the gain of the error amplifier. When the voltage signal is higher than the threshold voltage established beforehand, for making a power factor higher, the AC detecting circuit decreases the gain of the error amplifier. | 11-07-2013 |
20130307497 | SWITCHING POWER SUPPLY DEVICE - Aspects of the invention include a switching power supply device that includes a zero current detecting circuit that detects zero current of electric current flowing through the inductor to turn ON the switching element, an ON width generating circuit that determines the ON width of the switching element to turn OFF the switching element, and an OFF width detecting circuit that detects the OFF width of the switching element based on the output of the ON width generating circuit and the output of the zero current detecting circuit, and holds the OFF width until the next operating cycle. Aspects of the invention also include an ON width adjusting circuit that is included in the ON width generating circuit and adjusts the ON width of the switching element in the next operation cycle according to the width detected by the OFF width detecting circuit. | 11-21-2013 |
20130308359 | SWITCHING POWER SUPPLY DEVICE - In some aspects of the invention, a zero current detecting circuit of a switching power supply device detects a gradient of the current flowing in an inductor in the OFF state of the switching element and detects the timing at which the current through the inductor becomes zero corresponding to the detected gradient of the inductor current. Specifically, the zero current detecting circuit receives a signal for controlling ON/OFF driving of the switching element and a voltage signal proportional to the current flowing through the inductor in an OFF state of the switching element. The voltage signal can be compared sequentially with first and second comparison reference voltages to control charging and discharging of a capacitor. Further, the zero current detecting circuit can detect a timing at which the charging and discharging voltage of the capacitor as the timing of zero current flowing through the inductor. | 11-21-2013 |
20130343097 | SWITCHING POWER SUPPLY - A switching power supply achieves simultaneously achieves suppression of surge voltage and satisfactory transient response. The switching power supply comprises a switching element connected to a primary winding of an isolation transformer, a resonance capacitor connected to the switching element, an output capacitor connected to a secondary winding of the isolation transformer through a rectifying diode, and a control circuit ON/OFF driving the switching element. The control circuit includes a restart circuit that delivers a restart signal to turn ON the switching element after a predetermined time from turning OFF of the switching element has passed. The control circuit also includes an initial operation setting circuit that sets a delay time in the restart circuit to be longer in a start up period of the power supply than in a normal operation time after the end of the startup period. | 12-26-2013 |
20140016363 | SWITCHING POWER SUPPLY - Aspects of the invention provide a switching power supply that exhibits an improved conversion efficiency. In aspects of the invention, a load condition detecting circuit sets a threshold voltage for determining the magnitude of the load on the DC-DC converter based on the maximum value of the output voltage of the power factor correction converter in a suspended period of the power factor correction converter. An operation permission signal is delivered when a feedback voltage that indicates the magnitude of the load of the DC-DC converter exceeds the threshold voltage. When the feedback voltage exceeds a threshold voltage that is set at a value higher than the threshold voltage, the operation permission signal is delivered. | 01-16-2014 |
20140016364 | SWITCHING POWER SUPPLY DEVICE - In some aspects of the invention, a load state detecting circuit is configured so that a threshold voltage for determining the size of a load of a DC-DC converter is set in the load state detecting circuit based on a maximum value of an output voltage of a power factor correction converter in an operation-stopped state of the power factor correction converter, so that the load state detecting circuit outputs an operation-enable signal when a feedback voltage indicating the size of the load of the DC-DC converter exceeds the threshold voltage. Thus, by way of some aspects of the invention, it is possible to provide a switching power supply device which can control enabling and stopping operation of a power factor correction converter reliably in accordance with a load state of a DC-DC converter obtaining a predetermined DC output voltage by switching an output voltage of the correction converter. | 01-16-2014 |
20140185334 | SWITCHING POWER SUPPLY - Aspects of the invention provide a switching power supply in which frequency reduction control in a light load condition both in a power factor correction converter and a DC-DC converter restrains energy loss and achieves optimum efficiency. A switching power supply can include a power factor correction converter and a DC-DC converter. The DC-DC converter can include a load condition detecting means for detecting a condition of the load, and a frequency reducing means for reducing a switching frequency in the DC-DC converter when a light load condition is detected by the load condition detecting means. The power factor correction converter can include a frequency reducing means for reducing a switching frequency in the power factor correction converter corresponding to the load condition detected by the load condition detecting means of the DC-DC converter. | 07-03-2014 |
20140313787 | SWITCHING POWER SUPPLY APPARATUS - A switching power supply apparatus, including a power converting device body configured to switch DC input power through a first switching element to thereby store the DC input power in an inductor, and to transfer the stored power to an output capacitor through a second switching element by use of resonance of the inductor, a control circuit configured to drive the first and second switching elements to alternately turn ON or OFF the two switching elements, to thereby resonate the inductor, and an overload detecting circuit configured to detect a load state of the power converting device body based on a peak value or an effective value of a resonance voltage generated from the resonance of the inductor, to thereby control operation of the control circuit. | 10-23-2014 |