Sunwayman M20A problem?

Yesterday I got a Sunwayman M20A. Very nice light. I really like it. The only thing that makes me wonder is that it emits a strange humming sound when it's on low. It's not loud, actually you need to hold the light's head close to your ear to hear it clearly, but I am not sure if something like that's normal or whether that's a sign of a defect. The sound is quite high pitched and constant when the low mode is activated. The sound disappears when I switch the light to the higher modes. Unfortunately I'm not very knowledgeable about such things, so hopefully you can help me out here. Thanks in advance.

Don't worry, its quite normal. My Nitecore EX11.2 does that as do other lights I have. It's called PWM i believe - though i can't remember what that stands for!

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Sammy_boy said:

It's called PWM i believe - though i can't remember what that stands for!

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selfbuilt suggests that there's no PWM in the SWM M20A. so who can confirm this info?

the Sunawaman website doesnt tell whether the torch *does have* PWM or *does not have* PWM AFAIK.
tss.

other CPF threads:
http://www.candlepowerforums.com/vb/showthread.php?300216-Sunwayman-M20A-R5-mini-review
http://www.candlepowerforums.com/vb...-Sunwayman-M20A-Review-A-Layman-s-Perspective

It does not matter if the led is driven with PWM or constant current.
The DC to DC step up part of the driver is of switched-mode power supply type (boost).
It works at a certain frequency that might cause a sound corresponding to the frequency used.

Not normal. Definately, send it back. Have it, it's quiet.

Thanks for the posts guys. The seller told me it would be no problem to return the light. Other than the sound it's a wonderful light. To my surprise I actually prefer it to 1 AA lights.

why not return it and then get it cheaper from ch*na en directo? mwaharhahaa
just kiddin hehe *CYPM*

:devil: