Entries |
Document | Title | Date |
20090021966 | METHODS AND APPARATUS FOR A CASCADE CONVERTER USING SERIES RESONANT CELLS WITH ZERO VOLTAGE SWITCHING - A method of providing power to a load is provided. A first series resonant converter is provided. A second SRC is operably coupled to the first SRC in a cascade connected arrangement. First and second zero voltage switching (ZVS)-assistance networks are operably coupled between the first SRC and the second SRC, such that the first and second ZVS-assistance networks are providing first and second ZVS-assistant currents flowing from each ZVS-assistance network to the cascade connected arrangement of SRCs. Power from a power source is received at the cascade connected arrangement of first and second SRCs, power from a power source. The cascade connected arrangement of first and second SRCs supplies an output voltage to the load in response to receiving power from the power source. | 01-22-2009 |
20090103336 | CONTROL APPARATUS - The present invention provides a control apparatus for detecting an early stage short circuit between the terminals of an electrolytic capacitor, and detecting a short circuit between a load that is connected in parallel to the electrolytic capacitor, the apparatus performing appropriate processing before an adverse effect is inflicted on peripheral equipment. In the control apparatus, microcomputers switch on a second relay; an electrolytic capacitor is gradually charged via a current-limiting resistor; a first voltage detection control for detecting a voltage between terminals of the electrolytic capacitor is performed when a first set time period has elapsed after the second relay has been switched on; and a second voltage detection control for detecting a voltage between the terminals of the electrolytic capacitor is performed when a second set time period, which is longer than the first set time period, has elapsed after the second relay has been switched on. | 04-23-2009 |
20090129129 | Switching power supply device - A switching power supply device | 05-21-2009 |
20090154204 | REVERSE BIASING ACTIVE SNUBBER - The present invention provides a transient suppression circuit for use with a rectifier coupled to a transformer. In one embodiment, the transient suppression circuit includes a triggering section configured to provide a timing signal corresponding to a dead time of the rectifier. Additionally, the transient suppression circuit also includes a biasing section coupled to the triggering section and configured to apply a reverse bias voltage to the rectifier based on the timing signal. | 06-18-2009 |
20090154205 | SNUBBER CAPACITOR RESETTING IN A DC-TO-DC CONVERTER - A DC-to-DC converter and associated methods are provided for controlling the discharge of snubber capacitances during a light/no load buck mode of operation. An operating method for a DC-to-DC converter detects conditions corresponding to a light/no load buck mode of operation, and, in response to the detection of that mode, controls the states of a first switch, a second switch, a first switched diode element, a second switched diode element, a third switched diode element, and a fourth switched diode element to facilitate discharging of a first capacitance element and a second capacitance element through a secondary winding of a transformer. | 06-18-2009 |
20090279329 | DIGITAL LATCH CONTROL CIRCUIT FOR OVER-VOLTAGE PROTECTION AND POWER CONVERTER USING THE CONTROL CIRCUIT - An AC/DC power supply with over-voltage protection includes a voltage converting circuit and a digital latch control circuit. The voltage converting circuit has a first-side winding, a second-side winding, and an auxiliary winding for providing a supply voltage according to the AC input voltage. The digital latch control circuit is coupled to the voltage converting circuit and utilized for latching a voltage level of the supply voltage at a first predetermined level according to an over-voltage protection (OVP) trigger signal, where the voltage converting circuit is disabled when the voltage level is latched at the first predetermined level. | 11-12-2009 |
20100033997 | TIMED ELECTRICAL OUTLET AND A METHOD OF OPERATION THEREOF - A timed electrical outlet (or pluggable apparatus) and a method of operation thereof. The electrical outlet (or pluggable apparatus) includes a current sensor, a counter, and an electrical switch. When an electrical load is plugged into the electrical outlet (or pluggable apparatus), the current sensor senses the flow of current and triggers the counter to start counting. When the counter is finished counting, the counter triggers the electrical switch, opening the current path within the electrical outlet (or pluggable apparatus) such that electrical current no longer flows to the electrical load. | 02-11-2010 |
20100039838 | ELECTROSTATIC DISCHARGE CONDUCTING PATHWAY HAVING A NOISE FILTER SPARK GAP - A printed circuit board includes a primary region, a secondary region and an isolation region disposed between the primary region and the secondary region to galvanically isolate the primary region from the secondary region. The primary region is to be coupled to an AC source. The primary region also includes an electrostatic discharge (ESD) conducting pathway to redirect current to the AC source that crosses the isolation region. A spark gap is included in the ESD conducting pathway to filter noise and to provide a current path to the AC source for the current that crosses the isolation region. | 02-18-2010 |
20100073973 | Device for protection of power factor correction in three phase power supply and control method thereof - A power factor correction (PFC) protection device used when an abnormal current of a three-phase inverter occurs and a method of controlling the same are disclosed. If any mis-connection (or non-connection) occurs due to a mistake of a producer at a power-supply input terminal applied to the reactor and the switching element, a current applied to the switching element becomes an abnormal current, such that the PFC cannot be controlled. During the PFC control, the device detects a current waveform generated from the switching element at a current sensor of the common potential terminal, and determines whether there is a mis-connection caused by the abnormal current. If the mis-connection is decided, the device compares a current pattern with a mis-connection pattern, and changes the PFC control output applied to the switching element according to the searched mis-connection pattern, such that the PFC control can be normally carried out. | 03-25-2010 |
20100165677 | Electronic device having a circuit protection unit - An electronic device includes a circuit protection unit providing over-current protection to a main circuit and including a series connection of first and second current limiting circuits, and a normally-open branch circuit coupled in parallel to the first current limiting circuit and operable to conduct when a voltage across the first current limiting circuit reaches a first predetermined threshold voltage not greater than an endure voltage of the first current limiting circuit. Prior to conduction of the branch circuit, the first current limiting circuit maintains a current flowing therethrough at a first limit value when a current flowing through the main circuit reaches the first limit value. Upon conduction of the branch circuit, the second current limiting circuit maintains a current flowing therethrough at a second limit value greater than the first limit value when the current flowing through the main circuit reaches the second limit value. | 07-01-2010 |
20100277959 | POWER SUPPLY MODULE - A power supply module includes a rectifying and filtering unit, a pulse width modulation (PWM) unit, a voltage transforming unit, a sampling and comparing unit, and an overvoltage protection unit. The rectifying and filtering unit receives an alternating current (AC) voltage, and generates a filtered primary DC voltage. The PWM unit is configured for generating pulses. The voltage transforming unit transforms the filtered primary DC voltage into the DC voltage according to the pulses. The sampling and comparing unit samples the DC voltage, and generates an overvoltage signal when the sampled DC voltage exceeds a predetermined DC voltage. The overvoltage protection unit is coupled between the sampling and comparing unit and the PWM unit. According to the overvoltage signal, the overvoltage protection unit generates a first control signal to disable the PWM unit, and the overvoltage protection unit is self-locked. | 11-04-2010 |
20100328973 | AC COUPLED SWITCHING POWER SUPPLY AND METHOD THEREFOR - A circuit for converting high voltage AC to low voltage DC has an input capacitor coupled an input AC source. A rectifier is coupled to the input capacitor. A switch is coupled to the rectifier. A voltage regulator is coupled to the switch. The voltage regulator regulates an output of the circuit by closing the switch when a rising edge of a rectified AC voltage is below an output voltage and opens the switch when the output voltage reaches a regulation voltage. A storage capacitor is coupled to the switch. | 12-30-2010 |
20110058397 | SYSTEMS AND METHODS FOR POLYPHASE ALTERNATING CURRENT TRANSFORMER INRUSH CURRENT LIMITING - An inrush current protection circuit for a polyphase alternating current power system may include a plurality of current limiting resistors, each of which is electrically coupled in series between a respective one of a plurality of phases of the polyphase alternating current power source and a respective input of a polyphase transformer rectifier unit. The circuit may also include a plurality of power switches, each of which is electrically coupled in parallel with a respective one of the current limiting resistors, such that when each of the power switches is closed, essentially no electrical current flows through the respective current limiting resistor. The circuit may also include a power switch controller configured to control each of the power switches to be open such that an inrush current passes through the respective current limiting resistor rather than the power switch, and to be closed after a time delay has passed. | 03-10-2011 |
20110110128 | Preventing metal oxide varistor (MOV) from releasing smoke, smell, and/or sound - A system includes an electrical component, a MOV, a voltage sensor, and a circuit. The MOV is connected in parallel to the electrical component. The voltage sensor detects a voltage over the MOV and the electrical component. The circuit removes power in response to the voltage sensor detecting the voltage over the MOV and the electrical component being greater than a threshold voltage for a length of time greater than a threshold length of time. Removing power prevents the MOV from releasing one or more of smoke, smell, and sound. The MOV is thus not damaged as a result of a power surge. The system may be a power supply, or another type of electrical system. The electrical component may be a capacitor, or another type of electrical component. | 05-12-2011 |
20110249476 | VOLTAGE DETECTOR AND PROTECTION APPARATUS USING THE SAME - A voltage detector includes a zener diode having a cathode connected to a detect terminal of the voltage detector, a junction field effect transistor having an input terminal connected to an anode of the zener diode, and a resistor connected between an output terminal and a control terminal of the junction field effect transistor. When the voltage on the detect terminal is higher than the breakdown voltage of the zener diode, the junction field effect transistor produces a current flowing through the resistor, and thereby a detection signal can be obtained from the voltage across the resistor. | 10-13-2011 |
20130016541 | AC/DC CONVERTER STATION AND A METHOD OF OPERATING AN AC/DC CONVERTER STATIONAANM Norrga; StaffanAACI StockholmAACO SEAAGP Norrga; Staffan Stockholm SEAANM Jonsson; Tomas UAACI VasterasAACO SEAAGP Jonsson; Tomas U Vasteras SEAANM Shukla; AnshumanAACI VasterasAACO SEAAGP Shukla; Anshuman Vasteras SE - The present invention relates to an AC/DC converter station for interconnection of a DC transmission line and an AC network, the AC/DC converter station including an AC/DC converter and a control system configured to control the AC/DC converter. The AC/DC converter station comprises a capacitor connected in series between the AC/DC converter and the AC network, and a voltage measurement device arranged to measure the voltage across the capacitor. The AC/DC converter further comprises a control system connected to the voltage measurement device and arranged to receive, from the voltage measurement device, a signal indicative of a measured voltage. The control system is arranged to perform the control of the AC/DC converter in dependence of the signal received from the voltage measurement device. The invention further relates to a method of operating an AC/DC converter station. | 01-17-2013 |
20130044523 | Power supply having a surge protection circuit - A power supply having a power protection circuit has a rectification circuit and a converter. An input terminal of the rectification circuit is connected with the AC mains. A first voltage dependent resistor is connected with the AC mains. The converter has a transformer. A primary side of the transformer is connected with an output terminal of the rectification circuit, and the secondary side is connected to a power output terminal and a ground terminal. A Y capacitor is connected between the primary side of the transformer and the ground terminal. A surge protection module is connected between the first voltage dependent resistor and the Y capacitor. When a surge occurs between the primary and secondary sides of the transformer, a surge current is shunted by the surge protection module to the ground terminal through the Y capacitor without damaging internal components or circuits inside the power supply. | 02-21-2013 |
20130063989 | INTERFACE ARRANGEMENT BETWEEN AC AND DC SYSTEMS USING GROUNDING SWITCH - An interface arrangement for connection between an AC system and a DC system and to a method of disconnecting a DC system from an AC system are disclosed. The arrangement includes a converter for conversion between AC and DC having a DC side for connection to the DC system and an AC side for being coupled to the AC system, a set of circuit breakers coupled between the AC side of the converter and the AC system and a breaker assisting unit including a set of branches connected between the AC side of the converter and ground, where each branch includes a switch in series with an impedance element. | 03-14-2013 |
20130155733 | GENERATING A FAST RESET-SIGNAL USING A FAULT-PROTECTION LATCH - Methods and apparatuses are disclosed for monitoring an ac input for fault conditions. The ac input may be monitored by a latch-reset that uses the ac input to charge a line detection capacitor. The latch-reset may be configured such that the voltage at one end of the line detection capacitor drops below a line detection threshold voltage when the ac input is removed for longer than an allowable period of time or if the voltage of the ac input falls below an acceptable value. The drop in voltage at the end of the capacitor may cause an electrically coupled transistor to switch, thereby causing a reset-signal to be generated. | 06-20-2013 |
20130176755 | DIMMER CONTROL WITH SOFT START OVER-CURRENT PROTECTION - This document discloses, among other things, apparatus and methods for dimmer control. In an apparatus example, a circuit can include an input configured to receive a control signal, a controller configured to modulate a pulse width of a pulse train using the control signal when the controller is enabled, an output configured to provide the pulse train to a driver, and first and second current limit detectors configured to receive load current information of the driver and to terminate an active pulse of the controller when a value of the load current information exceeds a threshold. | 07-11-2013 |
20130194841 | POWER SUPPLY APPARATUS AND PRINTING APPARATUS - This invention is directed to a power supply apparatus and a printing apparatus, which have a function of easily relaxing an output voltage rise caused by an abrupt decrease in load current by a simple arrangement. In an embodiment of the invention, a dummy load is connected to some of power supply circuits included in the power supply apparatus. When an input voltage from a DC power supply falls below a predetermined threshold value, a power supply from the power supply circuit to an integrated circuit to which an electric power is supplied is stopped in synchronism with a reset signal output to the integrated circuit. At this time, an electric power from the power supply circuit is partially supplied to the dummy load, thereby relaxing an abrupt variation of the output voltage. | 08-01-2013 |
20130301319 | PRINTED CIRCUIT BOARD - A power source circuit includes a switching circuit | 11-14-2013 |
20140085947 | OFF-LINE POWER CONVERTER AND INTEGRATED CIRCUIT SUITABLE FOR USE IN SAME - An off-line power converter includes an integrated circuit power factor controller including a multi-function input terminal, a drive terminal for providing a drive signal to a gate of a drive transistor, a processing circuit coupled to the multi-function input terminal and, based on a signal received from the multi-function input terminal, providing at least one current signal representative of a current conducted in the off-line power converter, and at least one voltage signal representative of a voltage provided to a load, and a controller for providing the drive signal selectively in response to the at least one current signal and the at least one voltage signal. | 03-27-2014 |
20140153301 | AC SIGNAL DETECTOR AND THE METHOD THEREOF - An AC signal detector having: a rectify circuit having a first input terminal and a second input terminal configured to receive an AC signal, and an output terminal configured to provide a rectified signal based on the AC signal; a detecting circuit having an input terminal coupled to the output terminal of the rectify circuit to receive the rectified signal, and an output terminal configured to provide a square signal based on the rectified signal; and an unplug indicate circuit having an input terminal coupled to the detecting circuit to receive the square signal, and an output terminal configured to provide an unplug indicate signal based on the square signal. | 06-05-2014 |
20140307491 | OFFLINE POWER CONVERTER AND THE METHOD THEREOF - An offline power converter provides low EMI and quick reaction by slowly turning off a power switch at normal operation, and fast turning off the power switch when surge event happens. | 10-16-2014 |
20140328094 | APPARATUS, SYSTEM, AND METHOD FOR PROVIDING POWER REDUNDANCY TO A DEVICE DESIGNED TO DRAW POWER FROM A SINGLE EXTERNAL POWER ADAPTER - An apparatus may include a plurality of power inputs configured to receive direct current from a plurality of external power adapters that convert alternating current to direct current. The plurality of external power adapters may include a primary external power adapter and at least one backup external power adapter. The apparatus may also include a power output configured to provide direct current to a device. In addition, the apparatus may include a switching mechanism that, when the primary external power adapter is operational, supplies direct current from the primary external power adapter to the power output and, when the primary external power adapter fails, supplies direct current from the backup external power adapter to the power output. Various additional apparatuses, systems, and methods are also disclosed. | 11-06-2014 |
20150023073 | POWER CONTROL DEVICE AND IMAGE FORMING APPARATUS INCLUDING THE SAME - A power control device and an image forming apparatus including the same are disclosed. A power control device meets the need for low power consumption by minimizing standby power consumption in a plug-on state of an electronic apparatus, and meets the safety requirements by increasing a discharging rate of an X-cap or an E-cap in a plug-off state. The power control device includes a first capacitor charged by AC power during input of the AC power, a rectifier converting the AC power to DC power, a second capacitor disposed at an output of the rectifier, and a discharge circuit including at least one discharge resistor, and a first switch and a second switch configured to be alternately turned on/off in response to supply and interruption of the AC power, and discharging at least one of the first and second capacitors via the at least one discharge resistor, in response to turn-off of the first switch and turn-on of the second switch. | 01-22-2015 |
20150043256 | OVERVOLTAGE PROTECTION SYSTEMS AND METHOD - A power supply system and method are disclosed. The system includes a power supply to generate an output voltage in response to a pulse-width modulation (PWM) signal and a DC main voltage. The system also includes an AC/DC converter to generate the DC main voltage based on an AC input voltage. The system further includes a power supply controller to generate the PWM signal based on feedback associated with the output voltage. The power supply controller includes a fault controller to detect an overvoltage condition associated with the power supply and to cause the AC/DC converter to disable the DC main voltage in response to the overvoltage condition. | 02-12-2015 |
20150124500 | APPARATUS FOR CONTROLLING SURGE VOLTAGE - Provided is an apparatus for controlling a surge voltage. An embodiment configures a snubber coil and a snubber rectifier on a secondary side circuit in series to control a high spike surge voltage across a rectifier on the secondary side. When the rectifier is turned-off, the snubber rectifier is turned-on for a predetermined time to control the surge voltage. | 05-07-2015 |
20160118877 | CURRENT SOURCE CONVERTER DIFFERENTIAL PROTECTION METHOD AND RELAY PROTECTION DEVICE - Embodiments of the present invention disclose a current source converter differential protection method, including: sampling, by a relay protection device, secondary side currents of current transformers on two sides of a protected current source converter, to obtain incomer-side three-phase currents, and outgoer-side three-phase currents; rectifying the incomer-side three-phase currents and the outgoer-side three-phase currents, to obtain an incomer-side input current and an outgoer-side output current which are equivalent; converting the incomer-side input current and the outgoer-side output current according to a current ratio of the current transformers on the two sides, to acquire a transient differential current and a transient restraint current; acquiring a differential current and a restraint current according to the transient differential current and the transient restraint current; and achieving differential protection according to the differential current and the restraint current. The embodiments of the present invention further disclose a relay protection device correspondingly. | 04-28-2016 |