International Rectifier Corporation

Cesare Bocchiola

Massimo Grasso

Toshio Takahashi

Stefano Clemente

Giovanni Galli

According to one disclosed embodiment, a power delivery circuit includes a switch for protection of a load in a reverse battery condition. The load is coupled in cascade with the protection switch, where the protection switch disconnects the load from the battery in the reverse battery condition. The protection switch does not include p-n junction diodes present in conventional protection switches using FETs. The protection switch utilizes, for example, a GaN HEMT, that does not include a p-n junction diode. Thus, the threat of internal conduction in the protection switch during a reverse battery condition is eliminated. The power delivery circuit also protects the load in a load dump condition.

Power delivery circuit having protection switch for reverse battery condition

A method of protecting a cylinder of a compressor comprising a piston, a linear permanent magnet (PM) having a coil and a magnet, and a sensor-less control of the PM for moving the piston in and out of the cylinder. The method including the steps of receiving a reference position of the piston from a temperature control loop; deriving a compensation voltage and a load spring effect information from a current through the coil; providing a model input voltage to a model of a mechanical structure of the compressor for predicting position of the piston, the model input voltage comprising a first voltage derived from the reference position; a compressor input voltage comprising the first voltage and the compensation voltage; and using a position control loop to recognize when the maximum compression ratio is desired and controlling the piston to achieve maximum compression ratio without causing damage to the discharge valve.

Sensor-less control method for linear compressors

An integrated boost inverter circuit including at least one inverter stage having series connected high- and low-side switches having a common node. Each switch having an anti-parallel connected diode connected across the switch, which diode can be an external diode or an internal body diode of the switch; at least one inductor connectable in series between a voltage source and the node of the at least one inverter stage; a bulk capacitor connected across the at least one inverter stage; and a load being connectable to the node of the at least one inverter stage, wherein at every switching cycle, when the low-side switch of the at least one inverter stage turns-ON the respective at least one inductor is charged and when the low-side switch turns-OFF, the current in the respective at least one inductor re-circulates through the anti-parallel connected diode of the high-side switch into the bulk capacitor.

Single stage integrated boost inverter motor drive circuit

A safety circuit for providing protection against failures that impact safety of an inverter circuit driving a Permanent Magnet Synchronous Motor (PMSM) including high and low side switches connected in a bridge and driven by a gate driver circuit during operation of the PMSM in a field weakening mode, the gate driver circuit including stages for driving the high and low side switches, the safety circuit comprising a main power supply and a back-up power supply for supplying voltage to the gate driver circuit driving the switches of the bridge of the inverter circuit, wherein if the main power supply fails to deliver adequate power to the gate driver circuit, the back-up power supply provides power to the gate driver circuit to allow the gate driver circuit to turn ON the low side switches and turn OFF the high side switches.

Protection circuit for permanent magnet synchronous motor in field weakening operation

Apparatus for providing electrical power to at least one inductor wherein the at least one inductor is disposed to inductively couple the electrical power to an electrically conductive object to heat the electrically conductive object by inducing electrical current to flow in the electrically conductive object, the apparatus comprising at least one inductor, at least one first half-bridge converter coupled across a DC bus and having an output coupled to a first terminal of the at least one inductor; and at least one second half bridge converter coupled across the DC bus and having an output coupled to a second terminal of the at least one inductor, each half bridge converter having first and second alternately conductive series connected switches connected between the DC bus, the at least one inductor being energized by alternately turning on respective ones of the first and second switches of each converter to cause current to flow from the DC bus alternatingly through the at least one inductor from the first and second converters.

Induction heating apparatus

A power factor correction circuit for driving a switch of a boost type converter circuit having an AC line frequency input, comprising a sense circuit for sensing and comparing the output voltage of the boost type converter circuit to a reference voltage, a circuit responsive to the output of the sense circuit for providing a drive signal for driving the switch, wherein the drive signal comprises a pulsed signal comprising a pulse grouping during each half cycle of the AC line frequency comprising at least one pulse wherein the number of pulses and frequency of the pulses of the pulse grouping changes with the output of the sense circuit up to a threshold value with the pulse width of the pulses being substantially constant; and when the output of the sense circuit has reached the threshold value, the pulse width of the pulses of the pulse grouping are varied in accordance with the output of the sense circuit.

Low switching frequency power factor correction circuit

An HID ballast includes a flyback power converter with a simplified topology that permits power factor correction while supplying constant output power to drive an inverter supplying low frequency modulated power to the HID lamp. A switch is coupled in series with a transformer in the power converter to control current through the transformer to provide constant output power. The off time of the switch contributes to controlling the power factor of the ballast circuit. The transformer is operated in critical conduction mode, with an indication of zero current in the transformer used to determine the control for the switch. An output of the flyback power converter provides a feedback signal to obtain constant power output based on switching intervals applied to the switch coupled to the transformer. This simplified topology reduces part counts while providing a robust control that can be flexibly applied to a number of HID lamps.

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Milanese, Italy

Cesare Bocchiola