29 results about "Forward converter" patented technology

The embodiment of the invention provides a magnetic isolation feedback circuit which comprises an error amplifier unit, a modulator unit and a demodulator unit. The magnetic isolation feedback circuit is used for transmitting an error signal of an output voltage sampling signal Vos of a secondary side of the LLC resonant triode converter to a primary side of the LLC resonant converter so as to control the duty ratio of a first primary side switching tube QH and a second primary side switching tube QL of the LLC resonant converter; the error amplifier unit is used for amplifying an error signal of the output voltage sampling signal Vos to generate an amplified error signal; the modulator unit is used for modulating the input amplified error signals into square wave signals with the same amplitude; and the demodulator unit is used for demodulating the modulated square wave signal into a direct current signal with the same amplitude. According to the scheme, the forward converter is used as a modulator, so that a magnetic isolation feedback circuit with good temperature characteristics and radiation resistance characteristics is provided.

A system for controlling power provided to an electronic device is disclosed herein. The system includes a switching direct current (DC) power source configured to provide an input voltage at a first frequency, a forward converter coupled to the switching DC power source, wherein the forward converter outputs a first voltage and a second voltage, a frequency multiplier coupled to the forward converter and configured to receive the first voltage as an input, a switch coupled to the frequency multiplier and configured to be driven by the frequency multiplier, wherein the switch outputs a fourth voltage, and a voltage multiplier coupled to the switch and configured to be driven by the switch, wherein the voltage multiplier receives the second voltage and outputs a fifth voltage that is greater than the second voltage.

A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducted through a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.

The application discloses a current mode staggered control converter and a control chip, wherein the converter comprises a VIN input power supply with a voltage of 20V-100V, forward transformers T1 and T2, two output paths formed by the transformers and subsequent devices, a capacitor C0 as a VCC pin filter capacitor, a resistor R3 as an RT pin resistor connected to the ground and used for controlling the frequency of an oscillator, capacitors C1 and C2 as COMP1 and COMP2 pin capacitors connected to the ground and used for adjusting loop stability, capacitors C3 and C4 as SS1 and SS2 pin capacitors connected to the ground and used for realizing soft start of the system, N3 and N4 as natural synchronous rectifier devices in the forward converter, the first output channel and the second output channel adopting the same structure, an auxiliary winding La providing power supply for an IC control chip VCC through a diode D1, and an output capacitor Cout1 as an output capacitor of the first channel. The whole system is driven and controlled by only one control chip, and the power density is improved, the volume of the scheme is reduced, the cost of the scheme is lowered, and the system performance is not sacrificed.

A DC-DC converter comprising a first and second input; a transformer comprising a primary-side main inductance between the first and second inputs and a secondary-side main inductance; a first MOSFET between the first input and a first terminal of the primary-side main inductance; a second MOSFET between the second input and the second terminal of the primary-side main inductance; a third MOSFET between the first input and the second terminal of the primary-side main inductance or between the second input and the first terminal of the primary-side main inductance; a first diode between the second input and the first terminal of the primary-side main inductance or between the first input and the second terminal of the primary-side main inductance; a capacitor in parallel with the first MOSFET, the second MOSFET, or the first diode;and a control or monitoring unit configured to switch the first and second MOSFETs on and off substantially simultaneously, to switch the third MOSFET on and off alternately with the first and second MOSFETs, and to switch the third MOSFET on with a first delay relative to switching off the first and second MOSFETs, and to switch the first and second MOSFETs on with a second delay relative to switching off the third MOSFETs;

The application discloses a forward converter soft switching control circuit and belongs to the technical field of analog integrated circuits, and aims to solve the problems of poor self-adaptation, low precision and difficulty in compensating system delay of an existing dead zone control scheme; the circuit comprises a zero-voltage switching detection circuit, a charge pump phase detector and a voltage-controlled dead zone time circuit, and the three components form a closed-loop negative feedback loop; the zero-voltage switching detection circuit monitors the drain voltage of a main switch tube and generates a ZVS pulse when the voltage is zero; the charge pump phase detector compares the phase difference between the ZVS pulse and the rising edge of a main switch tube driving signal and outputs an error voltage; and the voltage-controlled dead zone time circuit linearly adjusts the dead zone time according to the error voltage, so that the rising edge of the driving signal is aligned with the zero point of the drain voltage. The circuit can automatically compensate the driving delay, adaptively track the working condition change, realize soft switching, reduce the loss, optimize EMI and balance the high frequency and high efficiency of the converter.

The invention relates to the technical field of active magnetic compensation, and discloses an active magnetic compensation driving system based on a forward converter, and the system comprises a power module which comprises an AC-DC circuit, a double-end forward circuit and an auxiliary power supply; the constant current source module is connected with the output end of the power supply module, and the constant current source module comprises a coil load interface, a constant current structure and a current signal acquisition circuit, and the constant current structure is formed by four parallel MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) and an operational amplifier; one end of the constant current structure is connected with the coil load interface, and the other end of the constant current structure is connected with the current signal acquisition circuit; the digital control module comprises a control unit and a lower computer; the invention discloses a uniaxial Helmholtz coil and a fluxgate sensor. According to the invention, the output power and the precision can be improved, and the requirements of high-precision applications such as active magnetic compensation are met.

The invention relates to a DC-DC converter for an actuator in automation technology with overload protection. According to the invention, electrical states of two circuit regions of the DC-DC converter are monitored and evaluated by means of a logic circuit.

The invention discloses a forward and reverse laser photovoltaic micro inverter topological structure with a passive buffer circuit, and the structure comprises a solar photovoltaic panel, a decoupling capacitor, the passive buffer circuit, a forward and reverse excitation circuit, a transformer, and a full-bridge inverter circuit. The forward and flyback full-bridge inverter topological structure combines the advantages of a forward converter and a flyback converter, so that high power density can be realized, and high efficiency can be kept in a wide input voltage range. The invention provides a passive lossless buffer circuit. The transient voltage suppression diode is used as a basis for recovering and reusing leakage inductance energy, so that effective energy absorption is ensured, the voltage stress of a switching tube is reduced, and the working efficiency of the inverter is improved.

A forward converter includes a voltage conversion device, a switch and an auxiliary device. The voltage conversion device includes a primary winding and a secondary winding, and is configured to convert an input voltage into an output voltage. The switch is connected to the voltage conversion device, and is switched to make the voltage conversion device receive or not receive the input voltage. The auxiliary device is connected to the voltage conversion device. When the switch is cut off, the auxiliary device stores electrical energy released by the voltage conversion device and generates a compensation voltage, and when the switch is turned on, the auxiliary device provides the compensation voltage, wherein the compensation voltage and the input voltage have same polarity. The present disclosure further provides a forward power factor corrector including the forward converter described above and a rectifying device.

An isolated bipolar output self-voltage balancing DC-DC converter, the converter comprising a forward converter, a bipolar voltage balancing unit; the forward converter comprises a DC input source u in , a power switch S1, a reset inductor L p1 , a transformer T, a reset diode D p1 , a rectifier diode D1, a freewheeling diode D2, an inductor L 1, an output capacitor C 1; the bipolar voltage balancing unit comprises a rectifier diode D3, a freewheeling diode D4, an inductor L 2, an inductor L 3, an output capacitor C 2, a voltage balancing capacitor C p The application can effectively reduce the voltage imbalance problem caused by cross regulation ratio of the traditional forward converter in bipolar output, reduce voltage deviation, and the circuit control is simple, the automatic voltage balancing of the bipolar output is realized through the bipolar voltage balancing unit, without complex sampling and control algorithm, the control system design and implementation difficulty is low, and the application is suitable for the occasions requiring bipolar voltage power supply.

A forward converter (1, 1_1, 1_2, 1_3, 1_4, 1_5, 1_6) includes a voltage conversion device (20, 20_1, 20_2, 20_3, 20_4, 20_5, 20_6), a switch (10, 10_1, 10_2, 10_3, 10_4, 10_5, 10_6) and an auxiliary device (30, 30_1, 30_2, 30_3, 30_4, 30_5, 30_6). The voltage conversion device (20, 20_1, 20_2,20_3, 20_4, 20_5,20_6) includes a primary winding (201, N1) and a secondary winding (202, N2), and is configured to convert an input voltage (Vi) into an output voltage (Vo). The switch (10, 10_1, 10_2, 10_3, 10_4, 10_5, 10_6) is connected to the voltage conversion device (20, 20_1, 20_2, 20_3, 20_4, 20_5, 20_6), and is switched to make the voltage conversion device (20, 20_1, 20_2, 20_3, 20_4, 20_5, 20_6) receive or not receive the input voltage (Vi). The auxiliary device (30, 30_1, 30_2, 30_3, 30_4, 30_5, 30_6) is connected to the voltage conversion device (20, 20_1, 20_2, 20_3, 20_4, 20_5, 20_6). When the switch (10, 10_1, 10_2, 10_3, 10_4, 10_5, 10_6) is cut off, the auxiliary device (30, 30_1, 30_2, 30_3, 30_4, 30_5, 30_6) stores electrical energy released by the voltage conversion device (20, 20_1, 20_2, 20_3, 20_4, 20_5, 20_6) and generates a compensation voltage (Vca), and when the switch (10, 10_1, 10_2, 10_3, 10_4, 10_5, 10_6) is turned on, the auxiliary device (30, 30_1, 30_2, 30_3, 30_4, 30_5, 30_6) provides the compensation voltage (Vca), wherein the compensation voltage (Vca) and the input voltage (Vi) have same polarity. The present disclosure further provides a forward power factor corrector including the forward converter (1, 1_1, 1_2, 1_3, 1_4, 1_5, 1_6) described above and a rectifying device.

A power converter can include a half bridge comprising a high side auxiliary switch and a low side main switch, the half bridge having an input coupled to a DC voltage source, a series resonant circuit coupled to the output of the half bridge, the series resonant circuit comprising a resonant capacitor and a primary winding of a transformer, an output coupled to a secondary winding of the transformer by a rectifier, the output delivering a regulated output voltage to a load, and control circuitry that operates the main switch and the auxiliary switch substantially complementarily as a forward converter with zero voltage switching of the main and auxiliary switches to regulate the output voltage delivered to the load.

A series lithium battery pack SOC active equalization converter comprises an n-path output double-transistor forward converter, n-1 bridging capacitors and n lithium ion batteries, the n-path output double-transistor forward converter comprises power switches S1 and S2, reset diodes Dp1 and Dp2, an excitation inductor Lm, a transformer T, a first-path rectifier diode D1, a fly-wheel diode D2, an output inductor L1 and an output capacitor C1; the second path of rectifier diode D3, the fly-wheel diode D4, the output inductor L2, the output capacitor C2,..., and the like, and the nth path of rectifier diode D2n-1, the fly-wheel diode D2n, the output inductor Ln, and the output capacitor Cn. Compared with a traditional forward transformer equalization structure, the energy storage of the transformer is provided with a release loop, a reset circuit or a reset winding does not need to be additionally arranged, and the control difficulty and cost of the circuit are reduced.

The utility model relates to a magnetic integrated forward converter and electronic equipment. The forward converter comprises a primary side circuit, a secondary side circuit and an integrated magnetic part. The integrated magnetic part comprises a primary winding, a secondary winding, an output inductor winding and an integrated magnetic core. And the primary winding, the secondary winding and the inductance winding are wound on the integrated magnetic core. The primary side circuit is connected with the primary side winding to form a primary side loop; the secondary circuit is connected with the secondary winding to form an induction loop; and the secondary circuit is connected with the output inductor winding to form an output loop. When the primary side loop is conducted, a first current is generated on the primary side winding; the secondary winding generates a second current based on the first current induction; the second current flows into the output inductance winding through the induction loop and is output through the output loop; and the magnetic flux generated by the second current on the secondary winding and the magnetic flux generated by the second current on the output inductance winding are mutually counteracted. According to the invention, the magnetic core loss of the forward converter after magnetic integration can be reduced, the output current pulsation is reduced, and the overall power density is improved.

The present invention discloses a ZVS forward converter without additional windings. Primary power MOS transistors Q1 and Q2 are alternately turned on to ensure that the forward isolated output transformer is reset and that the primary power MOS transistor Q1 is turned on at zero voltage (ZVS). The voltage of the primary winding Np after MOS transistor Q1 is turned off is determined by the body diode of MOS transistor Q2 and the voltage across the resonant capacitor Cr. The drain-source voltage Vds1(t) of MOS transistor Q1 is the sum of the input voltage VIN and the voltage across the resonant capacitor Cr. Current is alternately exchanged between MOS transistors Q1 and Q2 within a switching cycle. The present invention reduces the winding complexity and manufacturing cost of the forward isolated output transformer. Furthermore, by eliminating additional windings and the leakage inductance between the windings, the drain-source voltage variation of the primary MOS transistor Q1 can be smoother.

A forward converter includes a voltage conversion device, a switch and an auxiliary device. The voltage conversion device includes a primary winding and a secondary winding, and is configured to convert an input voltage into an output voltage. The switch is connected to the voltage conversion device, and is switched to make the voltage conversion device receive or not receive the input voltage. The auxiliary device is connected to the voltage conversion device. When the switch is cut off, the auxiliary device stores electrical energy released by the voltage conversion device and generates a compensation voltage, and when the switch is turned on, the auxiliary device provides the compensation voltage, wherein the compensation voltage and the input voltage have same polarity. The present disclosure further provides a forward power factor corrector including the forward converter described above and a rectifying device.

The invention provides a series battery pack active equalization circuit, system and method. Comprising a series battery pack module, a switch connection module and a bidirectional forward converter module, the series battery pack module comprises a first battery and a second battery which are connected in series; the bidirectional forward converter module comprises a primary side part and a secondary side part, and the primary side part comprises a first equalization loop and a second equalization loop which are respectively used for energy transmission and energy recovery; the first equalization loop comprises a first bidirectional series switch network and a switch resonance unit which are respectively used for enabling the first equalization loop to be bidirectionally communicated and preventing the two sides of the first bidirectional series switch network from generating current abrupt change; the switch connection module comprises a first single-pole double-throw switch module and a second single-pole double-throw switch module which are respectively used for connecting the first battery to the first equalization loop or the second equalization loop and connecting the second battery to the secondary side part. According to the active equalization circuit of the series battery pack, the battery energy equalization efficiency is improved.

A method and apparatus for providing welding-type power, the method comprising receiving input power and pulse width modulating a first forward converter and a second forward converter such that the two forward converters operate as a pulse width modulated dual forward converter to provide a welding-type output. A phase relationship between the first forward converter and the second forward converter is selected from at least two available phase relationships using a controller. The controller includes a pwm module and the pwm module includes a phase relationship module. The at least two available phase relationships are at least two of variable phase shift, fixed phase interleaving, and in-phase lock. The selected phase relationship is maintained over a predetermined output range.

The utility model discloses a staggered forward soft switch, which comprises a first double-transistor forward converter, a second double-transistor forward converter, an absorption circuit and an output circuit, the system also comprises a first transformer T1 and a second transformer T2. The first two-transistor forward converter comprises a first MOS (Metal Oxide Semiconductor) transistor VT1 and a third MOS transistor VT3; the second two-transistor forward converter comprises a second MOS (Metal Oxide Semiconductor) transistor VT2 and a fourth MOS transistor VT4; the source electrode of the first MOS tube VT1 is connected with the first end of the primary side of the first transformer T1, and the second end of the primary side of the first transformer T1 is connected with the first end of the second winding of the second transformer T2; the source electrode of the second MOS tube VT2 is connected with the first end of the primary side first winding of the second transformer T2 after passing through the secondary side winding of the first transformer T1; the second end of the first winding of the primary side of the second transformer T2 is connected with the drain electrode of the fourth MOS tube VT4.

The invention discloses a forward converter soft switching control circuit, belongs to the technical field of analog integrated circuits, and aims at solving the problems that an existing dead zone control scheme is poor in self-adaption and low in precision, and system delay is difficult to compensate. The circuit comprises a zero-voltage switch detection circuit, a charge pump phase discriminator and a voltage-controlled dead time circuit which form a closed-loop negative feedback loop, wherein the zero-voltage switch detection circuit monitors the drain voltage of a main switching tube and generates a ZVS pulse during zero passage; the charge pump phase discriminator compares the phase difference between the ZVS pulse and the rising edge of the driving signal of the main switching tube, and outputs an error voltage; the voltage-controlled dead time circuit linearly adjusts the dead time according to the error voltage, so that the rising edge of the driving signal is aligned with the drain voltage zero crossing point. The circuit can automatically compensate driving time delay, adaptively track working condition changes, realize soft switching, reduce loss, optimize EMI, and give consideration to high frequency and high efficiency of the converter.

The present invention discloses a single-ended forward converter fault diagnosis method based on output voltage differential value. The method is based on the single-ended forward converter, including a switch device and a magnetic reset circuit on the primary side and an output rectifier diode D1, a freewheeling diode D2, an inductor and a capacitor on the secondary side. The method includes the following steps: obtaining the relationship between the output voltage and the duty cycle according to a small signal model corresponding to the single-ended forward converter, and calculating the differential value of the output voltage; judging the open-short circuit fault of the switch device and / or the open-short circuit fault of the capacitor according to the differential value; and also calculating the second-order differential value of the output voltage, and judging the open-short circuit fault of the freewheeling diode according to the second-order differential value.

To improve a power factor of a forward converter.SOLUTION: A forward converter 1 contains a voltage conversion device 20, a switch 10, and an auxiliary apparatus 30. The voltage conversion device 20 comprises a primary winding 201 and a secondary winding 202, and is constructed so as to convert an input voltage into an output voltage. The switch 10 is connected to the voltage conversion device 20, and switches whether to supply the input voltage to the voltage conversion device 20. The auxiliary apparatus 30 is connected to the voltage conversion device 20. When the switch 10 is disconnected, the auxiliary apparatus 30 accumulates an electric energy discharged by the voltage conversion device 20, and generates an auxiliary voltage, and when the switch 10 is turned on, the auxiliary apparatus 30 supplies the auxiliary voltage. The auxiliary voltage and the input voltage are the same polarity. In addition, the present invention provides a forward power factor improvement device containing the forward converter 1 and a rectification device.SELECTED DRAWING: Figure 1

To reduce power loss in a bipolar DC power transmission system. [Solution] The higher-level control device 10 in the DC power transmission system 100 measures the power of the return line 40G, calculates a total return line power value 110C which is the sum of the power of each return line 40G, calculates a correction value to correct the control amount so that the total return line power value 110C approaches zero, and corrects the command value of the control amount with the correction value, thereby obtaining the control amount for the positive-side forward converter 111CP and the negative-side forward converter 111CN.

A forward converter comprises a voltage conversion device, a switch and an auxiliary device. The voltage conversion device comprises a primary side winding and a secondary side winding, and is used for converting an input voltage into an output voltage. The switch is connected to the voltage conversion device and switches to enable the voltage conversion device to receive or not receive the input voltage. The auxiliary device is connected to the voltage conversion device, stores the electric energy released by the voltage conversion device and generates a compensation voltage when the switch is turned off, and provides the compensation voltage when the switch is turned on, and the compensation voltage and the input voltage have the same polarity. The invention further provides a forward power factor corrector comprising the forward converter and the rectifying device.

The invention discloses a common-ground isolation hybrid dual-output converter, and belongs to the technical field of converters. Comprising a switching tube, a transformer, a fly-wheel diode, a first capacitor, a rectifier diode and a second capacitor C2. According to the invention, the transformer is used for replacing a filter inductor, so that the transformer is additionally provided with one path of output meeting electrical isolation, and is suitable for more application scenes. The isolated output of the converter is similar to the output of a Forward converter, but a magnetic reset loop does not need to be designed, and the design of the transformer is optimized. The converter can realize soft switching-on of a secondary rectifier diode in a CCM state, and soft starting of the secondary rectifier diode and soft switching-off of a fly-wheel diode in a DCM state.

According to the DCDC power supply with the wide input voltage range and the high output voltage, the input series connection and output series connection type double-transistor flyback or double-transistor forward power supply modules are constructed, and the two same power supply modules are connected in an input parallel mode and connected in an output series mode, so that the input and output voltage stress of a single converter is reduced by half, and the output voltage stress of the single converter is reduced by half. And functions of a power supply with a wide input voltage range and a high output voltage are realized. According to the utility model, the voltage division of the two switch tubes in the double-tube flyback or double-tube forward converter is utilized at the same time, so that the single switch tube can select a 600V / 650V conventional withstand voltage model, the model selection of 1200V SiC mos is avoided, and the problems of difficult model selection, high cost and long device purchasing period of a power device are solved. According to the utility model, the conversion efficiency of a wide input voltage range and high output voltage power supply is greatly improved compared with a multi-stage cascade structure power supply, the miniaturization design of the power supply is facilitated, and the design volume of the power supply is reduced.

A load control device for controlling the amount of power delivered to an electrical load (e.g., an LED light source) includes first and second semiconductor switches, a transformer, a capacitor, a controller, and a current sense circuit operable to receive a sense voltage representative of a primary current conducted through a primary winding of the transformer. The primary winding is coupled in series with a semiconductor switch, while a secondary winding is adapted to be operatively coupled to the load. The capacitor is electrically coupled between the junction of the first and second semiconductor switches and the primary winding. The current sense circuit receives a sense voltage and averages the sense voltage when the first semiconductor switch is conductive, so as to generate a load current control signal that is representative of a real component of a load current conducted through the load.

To reduce power loss in a bipolar DC power transmission system. [Solution] In the DC power transmission system 100, the higher-level control device 10 calculates a correction power 110C3 based on the control function 110C2 if the difference between the DC voltage 110A2P, 110A2N and the average value 110C1P, 110C1N exceeds the threshold 110C2T. It then calculates the distribution amount obtained by distributing the correction power 110C3 to the positive-side forward converter 111CP or negative-side forward converter 111CN connected to the positive-side forward converter 111CP or negative-side forward converter 111CN, which are connected to the positive-side forward converter 111CP or negative-side forward converter 40N, where the DC voltage 110A2P, 110A2N does not exceed the threshold 110C2T. The control amount of the positive-side forward converter 111CP and negative-side forward converter 111CN corrected by the distribution amount is calculated.