Seaforth
member
Joined: 27/08/02
Posts: 273
Loc: East Anglia, Great Britain
|
When a power supply (wart-ish) starts buzzing......
#590039 - 11/03/08 09:20 PM
|
|
|
|
...........is it about to:-
a) burn my house down?
b) destroy,
either immediately or over time, the equipment it is supplying with power?
c)
buzz some more, but with no actual ill effects?
It's the actual supply buzzing
- not buzzing through the speakers. External wart-esque type.
Thanks a lot
|
Jeraldo
Joined: 10/09/05
Posts: 2131
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590113 - 11/03/08 11:30 PM
|
|
|
|
I vote for C. But I'm not informed!
Toroidal transformers in mains filtering units
can make an incredible racket.
Not quite the same thing, though.
|
bingo wings
Joined: 19/04/07
Posts: 79
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590131 - 12/03/08 12:16 AM
|
|
|
|
C.
If it is bothering you, open it up and glue the transformer down (as long as
you don't mind voiding the warranty, and make sure the glue doesn't dissolve the
insulation).
|
Steve Hill
member
Joined: 07/01/03
Posts: 13140
Loc: Oxfordshire
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590173 - 12/03/08 08:15 AM
|
|
|
|
C.
If it's an issue I suppose you could put a 4-way distribution board in some
sort of home-made acoustic isolation box which you could knock up in an hour or so.
Possibly less risky than pouring glue into the transformer!
--------------------
Dynamite with a laser beam...
|
James Perrett
Joined: 10/09/01
Posts: 9645
Loc: The wilds of Hampshire
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590186 - 12/03/08 09:21 AM
|
|
|
The transformer isn't happy but there could be a few reasons for this. If a
winding has simply come loose then it isn't really a problem - just annoying. If it is an American piece of gear then chances are the transformer is slightly under
specified when working at the European 50Hz frequency. The worst problem could
be that your gear is taking more current than it should which is overloading the
transformer. In this situation it ought to be protected by a fuse but fuses don't always
blow as fast as you would expect if the current is only slightly higher than the limit. Cheers James.
-------------------- JRP Music - Audio Mastering and Restoration.
http://www.jrpmusic.net
|
Martin Walker
Watcher Of The Skies
Joined: 28/02/01
Posts: 16375
Loc: Cornwall, UK
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590342 - 12/03/08 03:11 PM
|
|
|
If a transformer is buzzing inside a piece of gear it can sometimes be improved by opening
up the case and placing a chunk of neoprene between it and the case panel to prevent the
vibration (making sure of course that the transformer in question doesn't get too hot).
This has certainly helped me in the past! Martin
-------------------- YewTreeMagic
|
Spiked Lunch
Joined: 02/04/05
Posts: 995
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590360 - 12/03/08 03:37 PM
|
|
|
Sorry to hijack the thread but what's the score (1-nil  ) if the
transformer starts buzzing after 30 minutes use? This happens in my Akai
sampler - I imagine that it's something to do with the transformer warming up. Is it
dangerous? Cheers, Mike
-------------------- my music
|
Korff
Loose Cannon (Reviews Editor)
Joined: 20/10/06
Posts: 1978
Loc: The Wrong Precinct
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590364 - 12/03/08 03:43 PM
|
|
|
|
The same thing happens to my oldskool Boss ACA. However, since the noise is purely
acoustic (ie. no interference, it's actually just the wall-wart buzzing) I've decided to
ignore the problem and hope that it goes away. I find the bury-head-in-sand technique to
be most effective.
PS Mike, I got your message — cheers for that, it looks
fine! I'll let you know when we use it.
Chris
|
Martin Walker
Watcher Of The Skies
Joined: 28/02/01
Posts: 16375
Loc: Cornwall, UK
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590465 - 12/03/08 06:37 PM
|
|
|
Many transformers produce acoustic noise in response to changes in the mains supply -
occasionally this is obvious (you'll hear noises during brownouts when your lights dim)
but mostly the cleaner the waveform the quieter the transformers, and this can often
change hour by hour.
Martin
-------------------- YewTreeMagic
|
Keith_in_AZ
Joined: 07/10/05
Posts: 100
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Seaforth]
#590478 - 12/03/08 07:09 PM
|
|
|
|
My approach to the wall wart issue is to avoid buying equipmment that uses wall warts/line
lumps.
I much prefer sturdy AC connections with interchangable line cords.
|
bingo wings
Joined: 19/04/07
Posts: 79
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Steve Hill]
#590484 - 12/03/08 07:22 PM
|
|
|
Quote Steve Hill:
Possibly less
risky than pouring glue into the transformer!
No pouring! Just a spot of superglue! 
|
Spiked Lunch
Joined: 02/04/05
Posts: 995
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Korff]
#590543 - 12/03/08 10:30 PM
|
|
|
Quote Korff:
The same thing
happens to my oldskool Boss ACA. However, since the noise is purely acoustic (ie. no
interference, it's actually just the wall-wart buzzing) I've decided to ignore the problem
and hope that it goes away. I find the bury-head-in-sand technique to be most
effective.
PS Mike, I got your message — cheers for that, it looks fine! I'll
let you know when we use it.
Chris
Cheers Chris 
--------------------
my music
|
Jeraldo
Joined: 10/09/05
Posts: 2131
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Spiked Lunch]
#590608 - 13/03/08 02:15 AM
|
|
|
|
Wouldn't hurt to try snapping on a ferrite bead on the mains leads right at the
transformer.
|
Martin Walker
Watcher Of The Skies
Joined: 28/02/01
Posts: 16375
Loc: Cornwall, UK
|
Re: When a power supply (wart-ish) starts buzzing......
[Re: Jeraldo]
#590736 - 13/03/08 12:13 PM
|
|
|
Although that will filter out any RF interference it won't do anything for the common-mode
distortion (where the same interference is present on both live and neutral wires) which
is often what causes transformers to continue buzzing after the initial switch-on surge.
For this you'll probably need a substantially engineered mains isolation transformer. Martin
-------------------- YewTreeMagic
|
Previous
Topics
Next
Threaded
Edit
Reply
Quote
