Flextronics Ap, LLC

Minebea Company, Limited

Other

International Components Corporation

Arian M Jansen

Bahman Sharifipour

Mark D Telefus

Xiaoyang Zhang

Huian Dong

Bahmar Sharifipour

An electronic device such as an AC/DC power adapter includes a conductive heat dissipation system. The device contains heat generating components and is powered via power supply leads by an external power supply circuit. The device further contains a thermally conductive mass that is thermally coupled to both the heat generating components and to the power supply leads. When the power supply leads are coupled to receive electricity from the external power supply circuit, heat generated by the device is thermally conducted into the external power supply circuit via the power supply leads.

Apparatus for and method of cooling molded electronic circuits

Apparatus for and method of cooling electronic circuits

An electrostatic loudspeaker includes a front stator, first and second substantially conductive diaphragms, a center stator and a back stator. The front stator is connected to a safe reference potential such as earth ground. The first diaphragm, the center stator and the back stator are connected to individual positive, non equal DC bias voltages, referenced to the front stator. The second diaphragm is connected to a negative DC bias voltage. A high voltage audio signal, which is referenced to the front stator, is superimposed to the bias voltage of the center stator. The electrostatic loudspeaker can be driven by a single ended audio source. The electrostatic loudspeaker further features an improved electrical safety level.

Electrostatic loudspeaker with single ended drive

A power converter includes a transformer, a primary switch, an auxiliary switch, first and second resonance capacitors, and a secondary side rectification means. A switch mode power supply is formed to use reflected voltage and parasitic capacitance as an energy source for a transformer resonance. The auxiliary switch effectively exchanges energy between the primary inductance of the transformer and the first and second resonant capacitors. The auxiliary switch effectively switches the transformer resonance between two distinct frequencies. In one embodiment of the invention, the power converter can be, but is not limited to, a flyback converter and further includes a comparator and a driver. The comparator is for detecting the voltage across the second resonance capacitor and the driver is configured to drive the auxiliary switch based on the output state of the comparator. The resonant nature of the converter provides zero voltage (ZVS) for the primary switch as well as for the auxiliary switch.

Two terminals quasi resonant tank circuit

A current measurement device is configured to measure electrical current in a primary conductor that is electrically insulated from the current measuring device. The current measuring device includes a transformer with a saturable magnetic core formed with a central aperture and a current measuring circuit. The electrical conductor in which electrical current is to be measured is disposed in the central aperture of the magnetic core. The current measuring circuit includes a current source driven by a voltage ramp generator that is connected to the secondary winding in a direction opposite the flow of electrical current in the primary conductor. When the magnetic flux in the transformer core is equal and opposite the magnetic flux generated as a result of the electrical current flowing in the primary conductor, the voltage of the voltage ramp generator is representative of the DC or AC electrical current flowing in the primary conductor.

Current measuring device for measuring the electrical current flowing in an electrical conductor electrically isolated from the current measuring device

A system and a method for to use multiple power sources for supplying power to a load. The system and method use a triggering system to automatically and substantially cancel a ripple component of the input current drawn by the system. A master power source and a slave power source supply power to the load. The triggering system results in the two power sources having switching frequencies that are substantially equal and switching cycles that are substantially 180&#xb0; out of phase. Further, the method and the device contemplate the use of a local oscillator in the triggering system to ensure that the slave power source is triggered to the on position at a point in the switching cycle of the master power source that is approximately 180&#xb0; out of phase with a leading edge of the master switching drive signal. The system and method are advantageously used to provide a power factor correction front-end for a switch-mode power supply. Power supplies with a diverse array of relationships between power supplied and switching frequency can be used.

Master-slave critical conduction mode power converter

A power converter having a transformer with a primary side winding and a secondary side winding, each having a switch. When the primary master switch is switched on, the transformer charges. When it is switched off, the intrinsic capacitance of the secondary slave switch discharges generating the zero voltage switching condition for the secondary slave switch. The secondary slave switch is switched on at a time determined in accordance with the waveform generated by the transformer. When the secondary slave switch is switched on, the transformer discharges and ultimately the charge from an output capacitor flows into the transformer as a backflow which charges the transformer. The secondary slave switch is switched off at a time determined in accordance with a current flowing through said secondary switch. The intrinsic capacitance of primary master switch discharges generating the zero voltage switching condition for primary master switch which is then switched on.

Power converter having primary and secondary side switches

Power converter having independent primary and secondary switches

A circuit simulating the function of a diode in the sense that it conducts current in one direction and blocks current in the opposite direction, but which has a low forward voltage drop. A voltage comparator and a three terminal switch are connected so that the intrinsic reverse diode associated with the switch is harnessed to conduct current in the direction in which it is desired to conduct current and to block current in the direction in which it is desired to block current. A voltage comparator controls the control terminal of the three terminal switch to turn on the switch to conduct current and to interrupt current. Alternate embodiments of voltage comparators are disclosed. The voltage comparator may include charging and discharging transistors so that the switch turns on and off at a high speed. The invention further includes a method of conducting current in one direction and blocking current in a second direction which reduces power losses.

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Lake Forest, CA, United States of America

Arian M Jansen