Passive common mode filter and method for operating a passive common mode filter
AssigneeInternational Rectifier Corporation
InventorBrian Pelly
Life of this patent
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Abstract
An electromagnetic interference filter for filtering common mode current in an inverter device, the filter comprising: an inductor coupled in a least one power supply line to the inverter device; the inverter device having a ground return line, a capacitor coupled between the inductor and the ground return line; and a controlled switch coupled in series with the capacitor between the inductor and ground return line, and a control unit controlled in accordance with commutations in said inverter device whereby said switch is turned on when common mode current is drawn by said inverter device and turned off when common mode current ceases substantially to be drawn by said inverter device.
Claims26
An electromagnetic interference filter for filtering common mode current in an inverter device, the filter comprising:
- an inductor coupled in a least one power supply line to the inverter device;
- the inverter device having a ground return line;
- a capacitor coupled between the inductor and the ground return line;
- and
- a controlled switch coupled in series with the capacitor between the inductor and ground return line;
- and
- a control unit controlled in accordance with commutations in said inverter device whereby said switch is turned on when common mode current is drawn by said inverter device and turned off when common mode current ceases substantially to be drawn by said inverter device.
A method of filtering electromagnetic interference due to common mode current in an inverter device, the method comprising:
- switching common mode current pulses in a supply line including an inductor to the inverter device through a capacitor coupled between the supply line and a ground return line for the inverter device only when common mode current is drawn by the inverter device.
Dependencies are inferred from the claim text.