Self-bias emitter circuit
First Claim
1. An emitter circuit in a parametric loudspeaker for providing a bias voltage, the emitter circuit comprising:
- an emitter configured to emit ultrasonic signals;
a full-wave bridge rectifier configured to convert an alternating current (AC) carrier signal into a corresponding direct current (DC) voltage; and
a filter capacitor configured to reduce variations of the DC voltage at an output of the full-wave bridge rectifier in order to provide a DC bias voltage across the emitter, wherein the DC bias voltage is applied across the emitter without affecting carrier information used by the emitter to emit parametric information.
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Accused Products
Abstract
Self-bias emitter circuit configurations can use the amplitude of an input AC carrier signal to provide a DC bias voltage across an emitter for suitable operation. A self-bias emitter circuit can include a transductor with primary matched with an amplifier, while secondary can be matched to the emitter. Self-bias emitter circuit can also include a full-wave bridge rectifier or a center tap inductor in conjunction with two diodes to rectify the AC carrier signal into a corresponding DC voltage. This DC voltage can be subsequently filtered by a capacitor to provide a steady DC bias voltage across the emitter. Sufficiently small, decoupling capacitors can be installed at each side of the full-wave rectifier in order to decouple the DC bias voltage, while a sufficiently large capacitor can be installed between the emitter and secondary for preventing the applied DC bias voltage from flowing back to secondary.
174 Citations
18 Claims
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1. An emitter circuit in a parametric loudspeaker for providing a bias voltage, the emitter circuit comprising:
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an emitter configured to emit ultrasonic signals; a full-wave bridge rectifier configured to convert an alternating current (AC) carrier signal into a corresponding direct current (DC) voltage; and a filter capacitor configured to reduce variations of the DC voltage at an output of the full-wave bridge rectifier in order to provide a DC bias voltage across the emitter, wherein the DC bias voltage is applied across the emitter without affecting carrier information used by the emitter to emit parametric information. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An emitter circuit in a parametric loudspeaker for providing a bias voltage, comprising;
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an emitter configured to emit ultrasonic signals; a transductor including a primary winding and a secondary winding, the secondary winding including a first portion and a second portion; a full-wave bridge rectifier coupled to the second portion of the secondary winding, the full-wave bridge rectifier operable to convert an alternating current (AC) carrier signal into a corresponding direct current (DC) voltage; and a filter capacitor configured to smooth the corresponding DC voltage in order to provide a DC bias voltage across the emitter. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method for providing a bias voltage across an emitter, the method comprising:
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receiving an alternating current (AC) carrier signal at an emitter circuit, the emitter circuit including a transductor with a primary winding and a secondary winding, the emitter circuit being included in a parametric loudspeaker; converting the AC carrier signal into a corresponding direct current (DC) voltage; and reducing variations of the DC voltage to provide a DC bias voltage across the emitter included in the emitter circuit, the emitter being configured to emit ultrasonic signals. - View Dependent Claims (16, 17, 18)
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Specification