System and method for creating high powered EMC compliant power supply for industrial and military applications
The present invention is an apparatus and method for provisioning a compact power filter connection to a well-grounded connector in such a way as to include a capacitive and inductive circuit connection, extremely near the connector and filter, such that EMC compatibility is created in a space roughly 30% of traditional mechanisms and design approach to satisfy the aforementioned needs, provide the previously stated objects, include the above-listed features, and achieve the already articulated advantages. The present invention is carried out in a “post-internal ferrite bead re-radiation noise-less” manner, in a sense that ability to have noise introduced back onto a post-ferrite bead line has been greatly reduced.
1. A 1U rack system for provisioning at least 300 watts of power, which is compliant with MIL-STD 461 and DO-160 comprising:
a rack configured for containing a plurality of 1U industrial electronic components; and
a 1U industrial power supply disposed in said rack, said power supply comprising:
a shielded case;
a power output connector grounded to said case said power output connector comprising a plurality of pins;
a power provisioning line coupled to a power provisioning pin of said plurality of pins in said power output connector;
power source circuitry, completely disposed with said case, which is configured to provide at least 300 watts of power at least 20V through said power provisioning line;
a ferrite bead disposed at and about a terminal portion of said power provisioning line, where said ferrite bead is not a core of a toroidally wound inductor;
a circuit board electrically and mechanically coupled to said power output connector and directly coupled to said power provisioning line;
said circuit board containing a combination of resistive, capacitive and inductive components configured to provide electro-magnetic interference (EMI) filtering; and
said ferrite bead and said circuit board configured to operate in combination to filter high frequency noise from said power provisioning line and to reduce EMI emissions from said shielded case.
2. A system of claim 1 wherein said ferrite bead is a multi-aperture ferrite bead.
3. The system of claim 2 further comprising a plurality of fans disposed inside said case and on opposing sides of said single ferrite bead.
4. The system of claim 2 where said circuit board has an internal facing side and a connector facing side where said connector facing side is soldered directly to said power output connector.
5. The system of claim 4 wherein said power output connector is a substantially circular military power output connector, which is grounded in 360 degrees to said shielded case.
6. The system of claim 4 wherein said power provisioning line is one of a plurality of lines, all of which are coupled at said circuit board at a central location on said circuit board.
7. The system of claim 6 wherein said circuit board has a periphery region around said central location wherein said periphery region has a plurality of capacitors disposed therein.
8. The system of claim 7 wherein said circuit board is coupled to said shielded case with a low inductance path to ground.
9. The system of claim 8 wherein said low inductance path to ground comprises a bolt extending between said circuit board and said case.
10. The system of claim 9 wherein each of said plurality of lines is disposed in an aperture of said multi-aperture ferrite bead.
11. A power supply in a 1U LRU comprising:
a case, configured with shielding to reduce EMI emissions therefrom;
power supply circuitry disposed in said case and configured to deliver power;
an output connector with a shell portion which is grounded to said case;
a power provisioning line coupled to said circuitry and providing power to said output connector;
a capacitive circuit board coupled directly to said output connector and said power provisioning line;
a low inductance path from said capacitive circuit board to said case;
a ferrite bead disposed about a terminal portion of said power provisioning line, where said ferrite bead is not a core of a toroidally wound inductor; and
a low inductance path from said capacitive circuit board to said case.
12. The power supply of claim 11 wherein said ferrite bead comprises a multi-aperture ferrite bead.
13. The power supply of claim 11 wherein said ferrite bead is free of any direct physical contact with said capacitive circuit board.
14. The power supply of claim 11 wherein said ferrite bead is separated from said capacitive circuit board by a portion of said power provisioning line.
15. The power supply of claim 11 wherein said case is a 1U LRU.
16. The power supply of claim 11 wherein said capacitive circuit board has a central zone comprising a connector for coupling directly with said power provisioning line.
17. The power supply of claim 16 wherein said central zone is immediately surrounded by a zone comprising a plurality of capacitors.
18. The power supply of claim 17 wherein said central zone has an unmated connector protruding away from said capacitive circuit board and away from said output connector.
19. The power supply of claim 18 wherein said unmated connector is free of any connection to a conductor line not located within said capacitive circuit board.
20. A power supply in a 1U LRU comprising:
a 1U LRU case, configured with shielding to reduce EMI emissions therefrom;
power supply circuitry disposed in said case and configured to deliver at least 300 watts of power at least 20V;
an output connector with a shell portion which is grounded to said case;
a power provisioning line coupled to said circuitry and providing power to said output connector;
a capacitive circuit board coupled directly to said output connector and said power provisioning line;
a ferrite bead having a first aperture disposed about a terminal portion of said power provisioning line, where said ferrite bead is not a core of a toroidally wound inductor;
a low inductance path from said capacitive circuit board to said case;
wherein said ferrite bead is free of any direct physical contact with said capacitive circuit board;
wherein said ferrite bead is separated from said capacitive circuit board by a portion of said power provisioning line;
wherein said capacitive circuit board has a central zone comprising a connector for coupling directly with said power provisioning line;
wherein said central zone is immediately surrounded by a zone comprising a plurality of capacitors;
wherein said central zone has an unmated connector protruding away from said capacitive circuit board and away from said output connector; and
wherein said unmated connector is free of any connection to a conductor line not located within said capacitive circuit board.