Abstract: Optimal power supply topologies that do not use output bulk capacitors as well as freewheeling diodes in output section to therefore provide efficiency, cost, volume, and weight advantage over the existing solutions. The present invention applies a pulse-width modulated switched current at higher frequency (in order of 10 to 100 kHz) to LEDs without degrading optical performance. LEDs' average current control is attained using a feedback loop that senses the average value of LEDs' current and controls the current by varying the pulse width of applied current.

Abstract: Optimal power supply topologies that do not use output bulk capacitors as well as freewheeling diodes in output section to therefore provide efficiency, cost, volume, and weight advantage over the existing solutions. The present invention applies a pulse-width modulated switched current at higher frequency (in order of 10 to 100 kHz) to LEDs without degrading optical performance. LEDs' average current control is attained using a feedback loop that senses the average value of LEDs' current and controls the current by varying the pulse width of applied current.

Abstract: A motor drive circuit has a converter for coupling to an AC voltage source and an inverter coupled to the converter for providing a drive current for a motor. A common mode circulation loop is coupled to the converter and to the inverter, and circulates common mode current from both the converter and the inverter.

Abstract: A control system is provided for controlling varying alternating current (AC) to a load with varying resistance and inductance. A plurality of nested control loops may employ cascaded proportional controllers to provide desired control of a pulse width modulation (PWM) block to control an inverter that supplies AC power to the load. An AC feedback signal may be supplied to each proportional controller. An AC signal may be added to outputs of the proportional controllers.

Abstract: An electrical power supply system is provided with capacitor-based hold-up protection. Inrush current to the capacitor is passively limited with a combination of a resistor and a rectifying device connected to a hold-up capacitor. During start-up, the rectifying device may be reverse-biased and a portion of input current is shunted to charge the hold-up capacitor. In the event of input power failure, the rectifying device is forward biased and the capacitor may be discharged to a load of the power supply thereby providing hold-up protection for the load.

Abstract: A control system is provided for controlling varying alternating current (AC) to a load with varying resistance and inductance. A plurality of nested control loops may employ cascaded proportional controllers to provide desired control of a pulse width modulation (PWM) block to control an inverter that supplies AC power to the load. An AC feedback signal may be supplied to each proportional controller. An AC feed forward signal may be added to outputs of the proportional controllers.

Abstract: A protection circuit monitors the gate voltage of an insulated gate bipolar transistor (IGBT) or metal oxide semiconductor field effect transistor (MOSFET) to protect the transistor during a time when it is being turned on. In one embodiment, the circuit monitors a transient gate voltage of the transistor when it is turned on. A short or overcurrent condition is detected when the gate voltage exceeds a delayed reference signal.

Abstract: A motor drive circuit has a converter for coupling to an AC voltage source and an inverter coupled to the converter for providing a drive current for a motor. A common mode circulation loop is coupled to the converter and to the inverter, and circulates common mode current from both the converter and the inverter.

Abstract: A protection circuit monitors the gate voltage of an insulated gate bipolar transistor (IGBT) or metal oxide semiconductor field effect transistor (MOSFET) to protect the transistor during a time when it is being turned on. In one embodiment, the circuit monitors a transient gate voltage of the transistor when it is turned on. A short or overcurrent condition is detected when the gate voltage exceeds a delayed reference signal.

Abstract: An inductor including a magnetic core (30) including at least one magnetic core element (32), the magnetic core (30) having a first portion (38) spaced from and facing a second portion (42), at least one winding (36) supported by the magnetic core (30), and a thermally conductive element (10) having a thermal conductivity greater than about 100 w/mK in thermal contact with the first and second portions (38, 42), the electrically conductive element (10) defining a plurality of paths (26) from the first portion (38) to the second portion (42), the paths (26) being filled with an electrically insulative material (28). A method of cooling an inductor with a heat transfer device (10) is also disclosed.