|
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
|
|
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
In Reply to: That will just radiate the noise posted by Maxamillion on February 9, 2011 at 06:16:13:
There is always some parasitic inductance associated with capacitor leads and internal wiring. This forms a tank circuit with the capacitance and very large currents can flow if the circuit environment permits the cap to ring.
Your example shows how easily paid circuit designers can cause trouble by overlooking this behavior. I'm sure in their design model, the filter caps were represented as very low impedances at all elevated frequencies.
An alternative approach would have been to provide snubbers (R-C series networks) around each of the rectifier diodes, or even to replace the rectifiers with HexFRED or similar low storage devices. It is charge storage in the rectifiers that stimulates the ringing.
You are correct that noise suppression caps connected across the AC line also result in resonant behavior, unless appropriate series resistors are provided. Such caps only suppress noise in the frequency range between their effective corner frequency and their primary resonance.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- All real capacitors have a primary resonance. - Al Sekela 14:46:54 02/09/11 (4)
- Funny Thing, Al, Those Diodes - Maxamillion 06:06:15 02/10/11 (1)
- I've seen other reports about CREE Schottky rectifiers - Al Sekela 18:51:37 02/10/11 (0)
- RE: All real capacitors have a primary resonance. - Æ 22:57:09 02/09/11 (1)
- You need to ground the shield - Maxamillion 05:48:21 02/10/11 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
