Abstract: 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.

Abstract: 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.

Abstract: A current measurement device is disclosed that is configured to measure electrical current, both AC and DC, in a primary conductor that is electrically insulated from the current measuring device. Unlike known current measuring devices, the current measuring device in accordance with the present invention does not utilize a Hall effect device and is more accurate and less expensive than current measuring devices employing such Hall effect devices. The current measuring device in accordance with the present invention includes a transformer with a saturable magnetic core formed with a central aperture and a current measuring circuit. In one embodiment of the invention, the transformer is provided with a secondary winding and no primary winding. The electrical conductor, i.e. primary conductor, in which electrical current is to be measured is disposed in the central aperture of the magnetic core and thus acts as a primary winding having a single turn.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The invention is a power converter having a transformer with a primary side winding and a secondary side winding. Both the primary side and the secondary side have switches which are switched on and off alternately. When the primary master switch is switched on, the transformer charges. When the primary master switch 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.

Abstract: A variable inductor with a saturable core having three legs, including a center leg and two outer legs. A control winding is wound on the center leg and two outer windings are connected in parallel and wound on the outer legs. The inductances of the windings on the outer legs vary with the current through the control winding. The current through the control winding varies the saturation level of the outer legs. In one embodiment, the inductance of the control winding is substantially constant with a change in current in the control winding. In another embodiment, the outer legs are saturated and the center leg is not saturated. Portions of the core connecting the three legs are tapered down from the cross-section of the center leg to the cross-sections of the outer legs. The invention further includes methods of varying the inductance of an inductive circuit element in accordance with a control current.

Abstract: A power regulator is provided which employs a resonant circuit and permits regulation between a certain maximum value and zero. A series resonant circuit is adjusted to regulate power by adjusting the correspondence between the resonance frequency and the frequency of the voltage source such as an AC source delivering a sine wave or a square wave. Further, the output voltage is regulated to be lower than the voltage of the AC source when output current is zero. A capacitance is connected in parallel with the output of the power regulator to form a second resonant circuit with the inductance of the series resonant circuit. A method of power regulation is also contemplated.

Abstract: A system and a method may use variable-frequency power sources for supplying power to a load. The system and method use phase detection in order to automatically and substantially equalize the currents supplied to a load by each of the variable-frequency power sources, and to cancel a ripple component of the input current drawn by the system. First and second power sources supply power to the load. The power sources have a similar relationship between their respective variable switching frequencies and the power that they supply to the load. First and second switching frequencies of, respectively, the first and second power sources are locked to one another using phase detection to substantially equalize the power supplied to the load by each power source. The system and method are advantageously utilized to provide a power factor correction front-end for a switch-mode power supply. Power sources with non-linear and/or inverse relationships between power supplied and switching frequency can be used.

Abstract: 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 from a terminal A to a terminal K when the voltage at terminal A is higher than the voltage at terminal K and to interrupt current from terminal K to terminal A when the voltage at terminal K is higher than the voltage at terminal A. The switch terminal (source or drain) that is typically connected to the higher voltage of two voltage terminals is instead connected to the lower voltage of the two voltage terminals.