Patent application number | Description | Published |
20090103335 | OVERCURRENT-PROTECTED SWITCHING-MODE POWER SUPPLY - A DC-to-DC converter having an active switch connected between a pair of DC input terminals via the primary winding of a transformer whose secondary winding is connected to a pair of DC output terminals via a rectifying and smoothing circuit. Operating under the control of an output voltage detector circuit, a switch control signal generator rapidly turns the active switch on and off so as to keep the DC output voltage constant. For overcurrent protection, a current detect resistor is connected in series with the active switch for providing an uncorrected current detect signal indicative of the current flowing through the active switch. An overcurrent protector generates, in response to a clocked ramp voltage, a correction voltage which builds up with time during each conducting period of the active switch. The correction voltage is subtracted from the uncorrected current detect signal to provide a corrected current detect signal. The switch control signal generator is caused to turn off the active switch when the corrected current detect signal rises to an overcurrent threshold. | 04-23-2009 |
20090103338 | SWITCHING POWER SOURCE APPARATUS - A switching power source apparatus includes a switching element connected through a primary winding of a transformer to a voltage terminal of a DC input voltage, a rectifying-smoothing circuit to rectify and smooth a voltage induced by a secondary winding of the transformer and provide a DC output voltage, a control circuit for controlling ON/OFF of the switching element, and a delay circuit to generate a predetermined delay time. The control circuit detects the DC input voltage, starts a switching operation of the switching element if the DC input voltage has increased to or above a threshold value, and stops the switching operation of the switching element if the DC input voltage is lower than the threshold value and that a period during which the DC input voltage is continuously lower than the threshold value has reached the predetermined delay time. | 04-23-2009 |
20090174978 | SWITCHING POWER SUPPLY DEVICE - A switching power supply device includes: a switching element connected through a primary winding of a transformer to an output end of an input rectifying/smoothing circuit that rectifies and smoothes an alternating current input voltage and outputs a direct current input voltage; an output rectifying/smoothing circuit that rectifies and smoothes a voltage induced in a secondary winding of the transformer and outputs a direct current output voltage; and a control circuit that controls ON and OFF of the switching element. The control circuit includes an overvoltage protection circuit that detects a voltage corresponding to the direct current output voltage and a voltage corresponding to the alternating current input voltage, outputs an overvoltage operation prohibition signal for prohibiting ON and OFF operations of the switching element when the voltage corresponding to the direct current output voltage rises to a first threshold value or more, and releases the overvoltage operation prohibition signal when the alternating current input voltage drops and the voltage corresponding to the alternating current input voltage falls down below a second threshold value. | 07-09-2009 |
20100244800 | SWITCHING POWER SUPPLY UNIT AND CONTROL CIRCUIT FOR SAME - There is provided a switching power supply unit having an overcurrent detection circuit capable of automatically selecting either a current detection method using an resistor or a current detection method using an external current detection resistor and of performing optimized overcurrent protection depending on applications. In the control circuit of the switching power supply unit for detecting a current flowing through a high-side switch as a current detection signal and comparing it with an overcurrent detection threshold value to detect an overcurrent and turning off the high-side switch to protect the switching power supply unit, a first current detection terminal connected to a power supply side terminal of the high-side switch or to a load side terminal of the high-side switch and a temperature compensating means to switch for temperature compensation on an overcurrent detection threshold value or on a current detection signal are provided. | 09-30-2010 |
20110304309 | SWITCHING POWER SOURCE APPARATUS - A switching power source apparatus includes a high-side MOSFET | 12-15-2011 |
20120032660 | SWITCHING POWER SOURCE APPARATUS - A switching power source apparatus includes a high-side MOSFET | 02-09-2012 |
20120032661 | SWITCHING POWER SOURCE APPARATUS - A switching power source apparatus includes a high-side MOSFET | 02-09-2012 |
20120043949 | SWITCHING POWER SOURCE APPARATUS - A switching power source apparatus includes a high-side MOSFET | 02-23-2012 |
20140152277 | SWITCHING POWER SUPPLY DEVICE - The present invention includes: an ON-timer configured to control a period of time in which a main switching element is on; a voltage detecting circuit configured to detect an output voltage of a filter circuit; a triangular wave generator; a feed-forward circuit configured to generate a feed-forward output whose value decreases as a value of a DC voltage from a DC power supply increases; and a comparator configured to compare a second reference voltage generated by adding together a first reference voltage, a triangular wave signal from the triangular wave generator, and the feed-forward output from the feed-forward circuit, with the output voltage of the voltage detecting circuit, and based on a result of the comparison, output an ON-trigger signal for turning on the main switch element to the ON-timer. | 06-05-2014 |
20150084606 | DC/DC CONVERTER - The present invention includes: a zero crossing detection circuit which outputs a zero crossing signal when an inductor's regeneration period is completed; a light load detection circuit which compares an amplified error signal from an error amplifier and a threshold and outputs a light load signal; a timer circuit which outputs an intermittent operation enabling signal after a predetermined period based on the light load signal and zero crossing signal and outputs an intermittent operation disabling signal when the zero crossing signal is not outputted for a predetermined period; and an ON-OFF control controller which turns off a switching element when the amplified error signal falls below the threshold while the timer circuit is outputting the intermittent operation enabling signal, and turns on the switching element when the amplified error signal at least reaches or exceeds the threshold while the timer circuit is outputting the intermittent operation enabling signal. | 03-26-2015 |
Patent application number | Description | Published |
20120008553 | Wireless access system - A wireless access system, including plural wireless control stations; a wireless terminal device to transmit and receive data to and from the plural wireless control stations, wherein the wireless control stations adjust with each other to reserve data transmission periods so as not to overlap with those of the other wireless control stations and transmit data in the reserved periods, and the wireless terminal device transmits data to at least one of the wireless control stations through space-division multiple access communication. | 01-12-2012 |
20120069835 | WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION DEVICE, AND METHOD - A wireless communication system includes wireless terminals. Each of the wireless terminals includes an SDM transmitting unit that includes antennas and generates directional radio signals to be transmitted to other terminals, each of which is obtained by superimposing radio signals at the antennas, each of which is composed of modulated data for each of the other terminals; a single-system receiving unit; and a TDMA control unit that controls a transmission of the SDM transmitting unit and a reception of the receiving unit in a time division manner. Using a TDMA scheme, the wireless terminals are controlled such that one of the wireless terminals acquires a transmission right for a predetermined time period to simultaneously transmit the generated directional radio signals from the SDM transmitting unit, while during the predetermined time period, the receiving units of the other wireless terminals having no transmission right simultaneously receive their corresponding directional radio signals. | 03-22-2012 |
20120319775 | AUTOMATIC GAIN CONTROL APPARATUS AND METHOD - An automatic gain control apparatus for a wireless receiver, including multiple variable gain amplifiers, one variable gain amplifier provided for each one of multiple receive chains and a gain controller to control a gain of the variable gain amplifiers provided for the plurality of receive chains. The gain controller includes multiple output level measurement units to measure an output level of a corresponding receive chain; a common gain determination unit to determine a common gain for each of the variable gain amplifiers based on a statistical value obtained from the output levels; multiple adjusted gain determination units, each adjusted gain determination unit determining an adjusted gain independently for each variable gain amplifier within a range narrower than the range of the common; and a gain setting unit to set a gain to each of the variable gain amplifiers based on the common gain and the adjusted gain. | 12-20-2012 |