565 results about "Output transformer" patented technology

An amplifier is operable in push-pull mode, single-ended mode, or a composite mode that is an intermediate between single-ended and Push-pull modes. Moreover, at least one output device may be configured to operate using a high performance AC servo loop that functions the output device as a current source. Still further, a control input driver stage is provided that is capable of supplying sufficient AC current to overcome Miller capacitance induced roll off within the intended frequency spectrum of triode vacuum tubes. Additionally, methods are provided to substantially null or selectively introduce DC magnetic bias within the output transformer core. Still further, a solid state power supply stage provides substantial AC hum reduction during single-ended operation and simultaneously provides output voltage load regulation attributes similar to traditional vacuum tube rectifier circuits.

An efficient and flexible current-mode driver delivers power to one or more light sources in a backlight system. In one application, the current-mode driver is configured as an inverter with an input current regulator, a non-resonant polarity-switching network, and a closely-coupled output transformer. The input current regulator can output a regulated current source in a variety of programmable wave shapes. The current-mode driver may further include a rectifier circuit and a second polarity-switching network between the closely-coupled output transformer and a lamp load. In another application, the current-mode driver delivers power to a plurality of light sources in substantially one polarity by providing a regulated current to a network of time-sharing semiconductor switches coupled in series with different light sources coupled across each semiconductor switch.

In one embodiment, the present invention includes multiple gain stages to receive and amplify a differential input signal at different common mode voltages. The stages each may include a pair of linear NMOS gain transistors coupled to a primary coil of a given output transformer. One of the stages may include commonly coupled terminals coupled to a center tap of the primary coil of an output transformer of another stage, and a supply current provided to one of the stages is re-used for the other stage(s).

In case of driving a plurality of lamps with the use of a plurality of output transformers, a difference in the bright-ness of each lamp occurs by a dispersion of characteristics of the output transformers, and an object is to prevent such troubles. For this purpose, a primary side of a plurality of output transformers of a one input-plural output type are respectively connected, and illumination units are connected to the secondary side of each output transformer. All of the secondary output terminals of each output transformer are connected to the secondary output terminals of counter phase and are connected by forming a loop circuit with the connection of the output terminals in series in closed loom form. The illumination units are connected between the secondary output terminals of the output transformer and the output terminal of the other output transformer of counter phase with the output terminal.

Provided are an electrostatic transducer capable of reducing a loss in a damping resistor and realizing a flat frequency characteristic in a driving frequency band in the case of using a class-D power amplifier and an LC filter, a method of setting a circuit constant of the electrostatic transducer, an ultrasonic speaker, a display device, and a directional sound system and a driving circuit of a capacitive load . An electrostatic transducer includes: a class-D power amplifier that amplifies an input signal; and a low pass filter that has a plurality of pairs of inductors and capacitors, is connected to an output side of the class-D power amplifier, and serves to eliminate switching carrier components included in an output of the class-D power amplifier. An electrostatic load capacitor of the electrostatic transducer serving as a driving load is disposed at a capacitor, which is closest to the output side of the class-D power amplifier, of circuit elements forming the low pass filter, an electrostatic coupling capacitor and an output transformer are interposed between the electrostatic load capacitor of the electrostatic transducer and an inductor closest to the output side of the class-D power amplifier of the low pass filter, and a damping resistor is connected in series to a primary coil of the output transformer.

A resonant DC-DC converter used to drive an LED array includes a half-bridge converter configured to receive DC input power and produce a square wave voltage. A resonant tank circuit that includes an inductive element, a first resonance capacitor, and a second resonance capacitor, is coupled to the half-bridge converter to receive the square wave voltage such that a generally sinusoidal AC voltage is produced across the second resonance capacitor. An output transformer with a primary winding and one or more secondary windings, is coupled in parallel to the second resonance capacitor, and a clipping circuit is coupled to the primary winding such that the voltage across the primary winding does not substantially exceed the voltage of the DC input power. An output rectifier is coupled to the one or more secondary windings of the output transformer and is configured to produce a generally DC output voltage.