Arc4 current noise

[weisar]

Last night, I heared my arc4 has current noise when set to level 1. And then i tried other levels. There's no current noise between 2 to 6 level, but has little noise between 7 to 12, and no noise between 13 to 16.
What is this matter? Dose it harm to anything?

weisar.

 

[Gransee]

Yes, that is normal. The volume and frequency will change with temp, battery type, level selected, etc. Most of the time it is not audible. This is what is called "inductor sing" and is a result of the windings in the inductor vibrating. Again, this is normal and does not indicate any problem or damage.

Peter

 

[daloosh]

Thanks Peter for the succint explanation, I was wondering the same thing, as on level 1, it is noticeable. Also, I've noticed in my LSH-P the noise does vary depending on the battery I use.

daloosh

 

[stefx]

So you can hear the regulation working. Maybe Arc should offer a tuning fork for '10% remaining' frequency.

Stef

 

[Ty_Bower]

Is the inductor potted in epoxy? I don't know much about electronics, but I'd think a little dab would be enough to keep it silent.

 

[Gransee]

Yes, it is potted in epoxy. But at these power levels the epoxy only dampens some of the noise. /ubbthreads/images/graemlins/smile.gif

The flyback in a tv or your laptop power "brick" are also usually potted.

Peter

 

[Willmore]

I think the term is 'magnetorestriction'. It's the property of a substance to change size under magnetic flux. Most ferous metals do it to some extent. The Navy uses strongly magnetorestrictive materials for their sonar transducers. The amount of force that they can provide is critical when your vibrating element (speaker cone, so to speak) is being crushed by a few hundred meters of sea water.

 

[weisar]

Peter,

good to hear the confirm statement that the current noice is normal and does not indicate any problem or damage.

Thanks for the explanation.

 

[Archvile]

As a side note, my Surefire L4 also has a little "hiss" to it. I assume that this is what Peter is talking about with the Arc4. Normal operating circumstance.

 

[Gransee]

Depends where the hiss is coming from. /ubbthreads/images/graemlins/smile.gif The L4 switch hisses sometimes because the contacts are eating themselves.

Peter

 

[paulr]

I noticed my Arc4 making noise when the battery was getting low. I changed out the battery and the noise stopped.

 

[PeLu]

It is not a bug, it'a a feature:
So they even have an acoustic low battery warning!

 

[this_is_nascar]

... I can name that Arc4 in 3-notes. (I'm obviously showing my age).

 

[SilverFox]

Hello Ray,

I get it...

Another old fart.

Tom

 

[Archvile]

Pete,
The hiss sounds like it's coming from the LED module itself. It's a real faint hissing sound. I have to put it right against my ear to hear it. I just assume it's normal operating procedure.