Suppression of radiated EMI for power supplies
US4984146A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1990 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Mar 27, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/062
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention provides a means for suppressing radiated electromagnetic radiation in high current AC/DC power supplies. This radiation is the result of rectifier diode transient noise which is propagated through the electrical network of the power supply. The transient noise is propagated through the electrical and mechanical connections of the diodes to the transformer secondary. These connections have stray impedance which allows high frequency noise to be propagated through them. The stray impedances can be modulated to suppress the high frequency noise propagation without adding discrete inductor or capacitor elements to the electrical network. The modulation of the stray impedances is accomplished by adjusting the current sharing between rectifier diodes. This is accomplished by splitting the parallel connection between rectifier diodes, and making the connection of the diodes to the transformer secondary at various points along the secondary. The separate impedance of both the transformer and the individual connections will modulate the existing stray impedance to suppress the radiated electromagnetic noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.