Patent application number | Description | Published |
20120169421 | AUDIO AMPLIFYING CIRCUIT WITH IMPROVED NOISE PERFORMANCE - An amplifying circuit includes a first circuit component configured to receive and amplify first and second input voltages to generate an output voltage. The first circuit component is formed by a first amplifier and a second amplifier. A second circuit component is configured to provide a first offset current that is associated with a first input current of the first amplifier. The first offset current compensates for variation in the first input current. A third circuit component is configured to provide a second offset current that is associated with a second input current of the second amplifier. The second offset current compensates for variation in the second input current. | 07-05-2012 |
20120268084 | BRIDGELESS POWER FACTOR CORRECTION CIRCUIT - A bridgeless PFC circuit is provided. A low-frequency bridge leg includes a first diode and a second diode connected in series; a three-port network includes a switch tube and an inductor; a lightning and surge protection bridge leg includes a third diode and a fourth diode connected in series; a capacitor is connected between terminals of the low-frequency bridge leg, and between terminals of the lightning and surge protection bridge leg; a common terminal of the first and second diodes is connected to a terminal of an AC power, and a common terminal of the third and fourth diodes is connected to the other terminal; and the three-port network has two ports with the capacitor connected therebetween, and another port connected to the common terminal of the third and fourth diodes. Thus, EMI performance and efficiency can be improved and costs of the whole circuit can be lowered. | 10-25-2012 |
20130169362 | INPUT CLAMPING STRUCTURE FOR SOUND QUALITY IMPROVEMENT IN CAR-RADIO CLASS-AB POWER AMPLIFIER DESIGN - A clamping circuit for a class AB amplifier includes a reference voltage circuit, four NPN Darlington transistors having inputs coupled to the reference voltage circuit, and outputs for providing four clamped voltages, and a split NPN Darlington transistor having an input coupled to the reference voltage circuit, and four separate outputs for providing four AC ground voltages. | 07-04-2013 |
20130188793 | EMBEDDED SPEAKER PROTECTION FOR AUTOMOTIVE AUDIO POWER AMPLIFIER - A method of operating a speaker system including a speaker coupled to an amplifier, and a dedicated digital speaker protection circuit includes turning on the amplifier in a mute mode, after a first delay period, issuing a play command to the amplifier to place the amplifier in a play mode, but without an input signal during a second delay period, and performing a speaker offset detection during the second delay period, wherein, if there is an offset, then the amplifier is forced back into the mute mode, and if there is no offset, then the amplifier is allowed to continue to operate in the play mode. The method also includes issuing a speaker protection control signal or command if an offset is detected. | 07-25-2013 |
20140266534 | TRANSFORMER - There is provided a transformer including an E shaped and two I shaped magnetic cores and a first, second and third windings, wherein: one I shaped magnetic core is located between one side and a middle legs of the E shaped magnetic core, another is located between another side and the middle legs; there is an air gap on each of the two I shaped magnetic cores or two side or bottom legs of the E shaped magnetic core, the first winding is wound on a part of the magnetic cores where the air gap exists; the second and third windings are wound on the middle leg; and the first winding is connected in parallel with the second winding to constitute a primary winding; the third winding is a secondary winding. With the transformer provided by the invention, transformer winding loss can be reduced, and transformer efficiency can be improved. | 09-18-2014 |