Start-up circuit for DC fan
First Claim
1. A start-up circuit for a DC (direct current) fan, comprising:
- a digital-analog converter for converting a digital control signal to an analog control signal, the digital-analog converter comprising an output terminal;
a voltage sampling device connected to the output terminal of the digital-analog converter, the voltage sampling device comprising an output terminal;
a comparator comprising two input terminals and an output terminal, one of the input terminals being connected to the output terminal of the voltage sampling device;
a switching device for controlling start-up of the DC fan, the switching device being connected to the output terminal of the comparator; and
a feedback device for adjusting a current passing through the switching device, an output signal of the switching device being inputted to the other one of the input terminals of the comparator via the feedback device.
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Accused Products
Abstract
A start-up circuit which decreases a start-up current and stabilizes running of a DC fan. The start-up circuit includes a digital-analog converter for convert a digital control signal from a control chip to an analog control signal, a voltage sampling device connected to an output terminal of the digital-analog converter, a comparator, a switching device for controlling start-up of the DC fan, and a feedback device adjusting current passing through the switching device. The comparator includes two input terminals and an output terminal. One input terminal is connected to an output terminal of the voltage sampling device. The switching device is connected to the output terminal of the comparator. An output signal of the switching device is inputted to the other input terminal of the comparator via the feedback device.
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Citations
19 Claims
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1. A start-up circuit for a DC (direct current) fan, comprising:
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a digital-analog converter for converting a digital control signal to an analog control signal, the digital-analog converter comprising an output terminal;
a voltage sampling device connected to the output terminal of the digital-analog converter, the voltage sampling device comprising an output terminal;
a comparator comprising two input terminals and an output terminal, one of the input terminals being connected to the output terminal of the voltage sampling device;
a switching device for controlling start-up of the DC fan, the switching device being connected to the output terminal of the comparator; and
a feedback device for adjusting a current passing through the switching device, an output signal of the switching device being inputted to the other one of the input terminals of the comparator via the feedback device. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A start-up circuit for a DC (direct current) fan, comprising:
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a digital-analog converter for converting a digital control signal to an analog control signal, the digital-analog converter comprising an output terminal;
a voltage sampling device connected to the output terminal of the digital-analog converter, the voltage sampling device comprising an output terminal;
a comparator comprising two input terminals and an output terminal, one of the input terminals being connected to the output terminal of the voltage sampling device;
a buffer connected between the voltage sampling device and the comparator, for preventing a large current flow at the instant of power turn-on of the start-up circuit; and
a switching device for controlling start-up of the DC fan, the switching device being connected to the output terminal of the comparator. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. A start-up circuit for a direct current (DC) fan, comprising:
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means to receive a pulse width modulation (PWM) signal and translate said PWM signal to a control signal capable of being output by said means;
a buffer electrically connecting with said means for accepting said control signal so as to be electrically chargeable within a predetermined period before further transmitting said control signal;
a switching device electrically connecting with a direct current (DC) fan so as to be capable of activating said fan; and
a voltage stabilizer electrically connected between said buffer and said switching device, said voltage stabilizer capable of accepting said control signal from said buffer and a feedback signal from said switching device so as to transmit said control signal to said switching device for controlling said switching device to activate said fan. - View Dependent Claims (19)
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Specification