12 results about "Forward converter" patented technology

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.

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.

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 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.

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 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.

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.

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.