How can a Philips AC-DC transform make so much noise?

[Merciadri Luca]

Hi,

I am using a Philips HQ 8000 100-240V /D 50-60 Hz, 9W, shaver charger
and transformer. I always let it plugged in, and then, to charge the
shaver, I plug the shaver in the charger, and everything's right.

However, it makes a very irritating noise, some piercing one, even if
the shaver is not plugged. This sound is so much unbearable that I
have to disconnect it before going to bed. I know that, practically,
it is disadviced to let a transform connected to the network without
any output, but why is it making so much noise? I have dozens of other
transformers which never make such a noise.

Thanks.

 

[Jasen Betts]

On 2010-05-16, Merciadri Luca <merciadriluca@gmail.com> wrote:

Hi,

I am using a Philips HQ 8000 100-240V /D 50-60 Hz, 9W, shaver charger
and transformer. I always let it plugged in, and then, to charge the
shaver, I plug the shaver in the charger, and everything's right.

However, it makes a very irritating noise, some piercing one, even if
the shaver is not plugged. This sound is so much unbearable that I
have to disconnect it before going to bed. I know that, practically,
it is disadviced to let a transform connected to the network without
any output, but why is it making so much noise? I have dozens of other
transformers which never make such a noise.

http://en.wikipedia.org/wiki/Switched-mode_power_supply

serch for the text "acoustic noise" read the rightmost column

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[Jamie]

Merciadri Luca wrote:

Hi,

I am using a Philips HQ 8000 100-240V /D 50-60 Hz, 9W, shaver charger
and transformer. I always let it plugged in, and then, to charge the
shaver, I plug the shaver in the charger, and everything's right.

However, it makes a very irritating noise, some piercing one, even if
the shaver is not plugged. This sound is so much unbearable that I
have to disconnect it before going to bed. I know that, practically,
it is disadviced to let a transform connected to the network without
any output, but why is it making so much noise? I have dozens of other
transformers which never make such a noise.

Thanks.
It's possible that it hasn't enough load on it and is cycling on/off.

Some chargers are designed to do this if it does not detect a proper
load due to the possibility of a bad battery or doing battery detection
cycles.

And some, like I said, are just plain noisy with no load on them
because they are designed for the battery load which is much greater
than just sitting idle. Normally, there is a load in there to help this
out how ever, its been a big thing about wall adapters sucking power
while your device isn't plugged in. Vampire Wallworts is a slang name
for that. So the noise you hear could also be the detection circuit
operating and looking for a load to switch and it could be on the edge
of a trigger.

 

[Merciadri Luca]

On May 16, 12:33 pm, Jasen Betts <ja...@xnet.co.nz> wrote:

On 2010-05-16, Merciadri Luca <merciadril...@gmail.com> wrote:

Hi,

I am using a Philips HQ 8000 100-240V /D 50-60 Hz, 9W, shaver charger
and transformer. I always let it plugged in, and then, to charge the
shaver, I plug the shaver in the charger, and everything's right.

However, it makes a very irritating noise, some piercing one, even if
the shaver is not plugged. This sound is so much unbearable that I
have to disconnect it before going to bed. I know that, practically,
it is disadviced to let a transform connected to the network without
any output, but why is it making so much noise? I have dozens of other
transformers which never make such a noise.

http://en.wikipedia.org/wiki/Switched-mode_power_supply

serch for the text "acoustic noise"  read the rightmost column
Thanks. And so, I have nothing to do, do I? This is the only one which

I get such a problem with.

 

[John Fields]

On Sun, 16 May 2010 08:58:45 -0700 (PDT), Merciadri Luca
<merciadriluca@gmail.com> wrote:

On May 16, 4:45 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
  It's possible that it hasn't enough load on it and is cycling on/off.
   Some chargers are designed to do this if it does not detect a proper
load due to the possibility of a bad battery or doing battery detection
cycles.

   And some, like I said, are  just plain noisy with no load on them
because they are designed for the battery load which is much greater
than just sitting idle. Normally, there is a load in there to help this
out how ever, its been a big thing about wall adapters sucking power
while your device isn't plugged in. Vampire Wallworts is a slang name
for that. So the noise you hear could also be the detection circuit
operating and looking for a load to switch and it could be on the edge
of a trigger.
Okay, I just plugged the shaver in, and put my ear next to the
transformer, and, actually, the noise is really even more perceptible
when the saver is plugged. This doubles the noise.

---
have you contacted Philips' customer support?

 

[Merciadri Luca]

On May 16, 4:45 pm, Jamie
<jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:

  It's possible that it hasn't enough load on it and is cycling on/off.
   Some chargers are designed to do this if it does not detect a proper
load due to the possibility of a bad battery or doing battery detection
cycles.

   And some, like I said, are  just plain noisy with no load on them
because they are designed for the battery load which is much greater
than just sitting idle. Normally, there is a load in there to help this
out how ever, its been a big thing about wall adapters sucking power
while your device isn't plugged in. Vampire Wallworts is a slang name
for that. So the noise you hear could also be the detection circuit
operating and looking for a load to switch and it could be on the edge
of a trigger.
Okay, I just plugged the shaver in, and put my ear next to the

transformer, and, actually, the noise is really even more perceptible
when the saver is plugged. This doubles the noise.

 

[Merciadri Luca]

On May 16, 6:39 pm, John Fields <jfie...@austininstruments.com> wrote:

---
have you contacted Philips' customer support?
It does not look like some malfunction, simply some excessive noise,

and sure they'll tell me that this is normal.

 

[John Fields]

On Sun, 16 May 2010 10:43:26 -0700 (PDT), Merciadri Luca
<merciadriluca@gmail.com> wrote:

On May 16, 6:39 pm, John Fields <jfie...@austininstruments.com> wrote:
---
have you contacted Philips' customer support?
It does not look like some malfunction, simply some excessive noise,
and sure they'll tell me that this is normal.

---
If it's annoying to the point where it's depriving you of sleep, then
If it were me I'd let them know about it.

It's your life though... do what you like.

 

[Merciadri Luca]

On May 17, 12:05 am, John Fields <jfie...@austininstruments.com>
wrote:

If it's annoying to the point where it's depriving you of sleep, then
If it were me I'd let them know about it.
But you know, their servicing is always the same. That's the problem.

It's your life though... do what you like.
I can deactivate it, but, clearly, it is annoying.

 

[ehsjr]

Merciadri Luca wrote:

On May 17, 12:05 am, John Fields <jfie...@austininstruments.com
wrote:

If it's annoying to the point where it's depriving you of sleep, then
If it were me I'd let them know about it.

But you know, their servicing is always the same. That's the problem.

It's your life though... do what you like.

I can deactivate it, but, clearly, it is annoying.

Well, you've put in time and effort to post here. Why not
put in time and effort to contact Philips, as John mentioned?
Who knows - they might have a product recall on the thing,
or a simple fix. In any event, it couldn't hurt so you
might as well try it.

For a possible "quick fix", try putting a piece of foam
rubber or a terry cloth towel under the thing to see if
that damps the sound.

Ed

 

[Merciadri Luca]

On May 17, 5:27 pm, ehsjr <eh...@nospamverizon.net> wrote:

Merciadri Luca wrote:
On May 17, 12:05 am, John Fields <jfie...@austininstruments.com
wrote:

If it's annoying to the point where it's depriving you of sleep, then
If it were me I'd let them know about it.

But you know, their servicing is always the same. That's the problem.

It's your life though... do what you like.

I can deactivate it, but, clearly, it is annoying.

Well, you've put in time and effort to post here.  Why not
put in time and effort to contact Philips, as John mentioned?
Who knows - they might have a product recall on the thing,
or a simple fix.  In any event, it couldn't hurt so you
might as well try it.
Thanks. Done. I'll let you know.

For a possible "quick fix", try putting a piece of foam
rubber or a terry cloth towel under the thing to see if
that damps the sound.
It is on an `electrical extension' (I don't know if this is how you

call this) that I always disconnect, except when I want to charge the
shaver. The problem is that if I need it tomorrow, I cannot charge it
in my bedroom the night. Or, if I dare do this, I won't sleep(!), but
will be shaved tomorrow. Funny.

 

[Bob Masta]

On Sun, 16 May 2010 02:50:39 -0700 (PDT),
Merciadri Luca <merciadriluca@gmail.com> wrote:

Hi,

I am using a Philips HQ 8000 100-240V /D 50-60 Hz, 9W, shaver charger
and transformer. I always let it plugged in, and then, to charge the
shaver, I plug the shaver in the charger, and everything's right.

However, it makes a very irritating noise, some piercing one, even if
the shaver is not plugged. This sound is so much unbearable that I
have to disconnect it before going to bed. I know that, practically,
it is disadviced to let a transform connected to the network without
any output, but why is it making so much noise? I have dozens of other
transformers which never make such a noise.

Thanks.

Does the shaver actually plug into the charger via
electrical contacts, or is it inductively coupled?
If the latter, there are coils of wire in the
charger and shaver that form the primary and
secondary windings of a transformer. The
alternating magnetic field in the charger primary
induces a current in the shaver secondary, but
unlike a conventional transformer where the
windings are (hopefully) firmly attached to each
other and an iron core, here the shaver is
more-or-less free to move.

Try pressing pressing and holding the shaver into
the charger to see if that reduces the sound by
restricting motion. If that quiets it down, you
might rig up something like a heavy rubber band to
hold them together.

Another possibility is that the coils in the
charger and/or shaver are not securely mounted.
That would fit with the observation that you hear
sound even when the shaver is not plugged in. If
you can open the charger (disconnected from the
mains!) and get to the coil, you may be able to
anchor it with glue.

Best regards,


Bob Masta

DAQARTA v5.10
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
DaqMusic - FREE MUSIC, Forever!
(Some assembly required)
Science (and fun!) with your sound card!

 

[Merciadri Luca]

On May 18, 1:18 pm, N0S...@daqarta.com (Bob Masta) wrote:

Does the shaver actually plug into the charger via
electrical contacts, or is it inductively coupled?
If the latter, there are coils of wire in the
charger and shaver that form the primary and
secondary windings of a transformer.  The
alternating magnetic field in the charger primary
induces a current in the shaver secondary, but
unlike a conventional transformer where the
windings are (hopefully) firmly attached to each
other and an iron core, here the shaver is
more-or-less free to move.

Try pressing pressing and holding the shaver into
the charger to see if that reduces the sound by
restricting motion.  If that quiets it down, you
might rig up something like a heavy rubber band to
hold them together.

Another possibility is that the coils in the
charger and/or shaver are not securely mounted.
That would fit with the observation that you hear
sound even when the shaver is not plugged in.  If
you can open the charger (disconnected from the
mains!) and get to the coil, you may be able to
anchor it with glue.
Thanks for this answer. Actually, it is not charged by inductive

couple. There are simply two pieces of a conductive material at the
bottom of the dock, and plugging the shaver into the dock results in a
contact between the shaver and the charger, which therefore charges
it. I contacted Philips, and this is definitely not normal, they said.
I should get another one later. If I have some spare time, it is
possible for me to open the transformer, and check if everything is
right, this one being disconnected from the mains. Can I also open the
transformer? Thanks.

 

[Bob Masta]

On Tue, 18 May 2010 05:51:55 -0700 (PDT),
Merciadri Luca <merciadriluca@gmail.com> wrote:

On May 18, 1:18=A0pm, N0S...@daqarta.com (Bob Masta) wrote:
Does the shaver actually plug into the charger via
electrical contacts, or is it inductively coupled?
If the latter, there are coils of wire in the
charger and shaver that form the primary and
secondary windings of a transformer. =A0The
alternating magnetic field in the charger primary
induces a current in the shaver secondary, but
unlike a conventional transformer where the
windings are (hopefully) firmly attached to each
other and an iron core, here the shaver is
more-or-less free to move.

Try pressing pressing and holding the shaver into
the charger to see if that reduces the sound by
restricting motion. =A0If that quiets it down, you
might rig up something like a heavy rubber band to
hold them together.

Another possibility is that the coils in the
charger and/or shaver are not securely mounted.
That would fit with the observation that you hear
sound even when the shaver is not plugged in. =A0If
you can open the charger (disconnected from the
mains!) and get to the coil, you may be able to
anchor it with glue.
Thanks for this answer. Actually, it is not charged by inductive
couple. There are simply two pieces of a conductive material at the
bottom of the dock, and plugging the shaver into the dock results in a
contact between the shaver and the charger, which therefore charges
it. I contacted Philips, and this is definitely not normal, they said.
I should get another one later. If I have some spare time, it is
possible for me to open the transformer, and check if everything is
right, this one being disconnected from the mains. Can I also open the
transformer? Thanks.

Are you saying that the transformer is a separate
unit from the charger? Whichever the situation,
if the noise is coming from the unit with the
transformer, it's possible that the windings are
loose on the core, and might be fixed by a little
glue. As far as opening the case goes, many of
these are welded plastic with no convenient screws
to remove. I have had luck in the past cutting
open a wall-wart and re-glueing it later... worked
fine, but it sure looked ugly!

Best regards,



Bob Masta

DAQARTA v5.10
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, Sound Level Meter
Frequency Counter, FREE Signal Generator
Pitch Track, Pitch-to-MIDI
DaqMusic - FREE MUSIC, Forever!
(Some assembly required)
Science (and fun!) with your sound card!

 

[Merciadri Luca]

On May 19, 2:19 pm, N0S...@daqarta.com (Bob Masta) wrote:

On Tue, 18 May 2010 05:51:55 -0700 (PDT),



Merciadri Luca <merciadril...@gmail.com> wrote:
On May 18, 1:18=A0pm, N0S...@daqarta.com (Bob Masta) wrote:
Does the shaver actually plug into the charger via
electrical contacts, or is it inductively coupled?
If the latter, there are coils of wire in the
charger and shaver that form the primary and
secondary windings of a transformer. =A0The
alternating magnetic field in the charger primary
induces a current in the shaver secondary, but
unlike a conventional transformer where the
windings are (hopefully) firmly attached to each
other and an iron core, here the shaver is
more-or-less free to move.

Try pressing pressing and holding the shaver into
the charger to see if that reduces the sound by
restricting motion. =A0If that quiets it down, you
might rig up something like a heavy rubber band to
hold them together.

Another possibility is that the coils in the
charger and/or shaver are not securely mounted.
That would fit with the observation that you hear
sound even when the shaver is not plugged in. =A0If
you can open the charger (disconnected from the
mains!) and get to the coil, you may be able to
anchor it with glue.
Thanks for this answer. Actually, it is not charged by inductive
couple. There are simply two pieces of a conductive material at the
bottom of the dock, and plugging the shaver into the dock results in a
contact between the shaver and the charger, which therefore charges
it. I contacted Philips, and this is definitely not normal, they said.
I should get another one later. If I have some spare time, it is
possible for me to open the transformer, and check if everything is
right, this one being disconnected from the mains. Can I also open the
transformer? Thanks.

Are you saying that the transformer is a separate
unit from the charger?
The charger is connected to the transformer with a wire, simply. I

plug the shaver in the charger.

 Whichever the situation,
if the noise is coming from the unit with the
transformer, it's possible that the windings are
loose on the core, and might be fixed by a little
glue.  As far as opening the case goes, many of
these are welded plastic with no convenient screws
to remove.  I have had luck in the past cutting
open a wall-wart and re-glueing it later... worked
fine, but it sure looked ugly!
I'll know the problem thanks to Philips. Thanks.