Switching Mode power supply incorporating power line filter
First Claim
1. A power supply device, comprising a rectifier for converting an alternating current power supplied by an alternating current power source into a rectified direct current power;
- a power transformer coupled to the rectifier for inputting the rectified direct current power from a primary winding and inducing a rectified power to a secondary winding through the primary winding;
a switch unit connected in series with the primary winding for converting the direct current power supplied to the primary winding into alternating current power by on/off operations; and
a power line filter including a current-limiting device for reducing a differential mode noise appearing between a live supply line and a neutral line from the alternating current power source.
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Accused Products
Abstract
There is disclosed a switching mode power supply with a reduced EMI effect, comprising a rectifier for converting an AC power supplied by an AC power source into a rectified DC power, a transformer coupled to the rectifier for inputting the DC power from a primary winding and inducing a rectified power to a secondary winding through the primary winding, a switch unit connected in series with the primary winding for converting the DC power supplied to the primary winding into AC power by on/off operations, an output voltage feedback control circuit for providing pulses to drive the switch unit by controlling a switching duty cycle of the switching unit, and a power line filter including a unidirectional current-limiting device such as a diode for reducing differential mode noise appearing between a live supply line and a neutral line from the alternating current power source.
15 Citations
9 Claims
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1. A power supply device, comprising
a rectifier for converting an alternating current power supplied by an alternating current power source into a rectified direct current power; -
a power transformer coupled to the rectifier for inputting the rectified direct current power from a primary winding and inducing a rectified power to a secondary winding through the primary winding;
a switch unit connected in series with the primary winding for converting the direct current power supplied to the primary winding into alternating current power by on/off operations; and
a power line filter including a current-limiting device for reducing a differential mode noise appearing between a live supply line and a neutral line from the alternating current power source. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A power supply device, comprising
a rectifier for converting an alternating current power supplied by an alternating current power source into a rectified direct current power; -
a transformer coupled to the rectifier for inputting the rectified direct current power from a primary winding and inducing a rectified power to a secondary winding through the primary winding;
a switch unit connected in series with the primary winding for converting the direct current power supplied to the primary winding into alternating current power by on/off operations;
an output circuit coupled to the secondary winding for providing an output voltage for a load;
an output voltage feedback control circuit coupled to the power transformer and the switch unit for maintaining the output voltage at a predetermined value by regulating a switching duty cycle of the switch unit; and
a power line filter including a unidirectional current-limiting device for reducing a differential mode noise appearing between a live supply line and a neutral line extending from the alternating current power source. - View Dependent Claims (8, 9)
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Specification