ARC 4+ RF Emissions and Audible Emissions.

What kind of noises are you getting from your 4+'s? Is yours singing?!

Mine emits are variety of noises. At full power it hums quite noticeably. Around level 8 the wine is noticeable if the light is held right up to the pinna of your ear. Actually the hum at L1 is only audible in the same sense, but considerably louder.

Bringing the Arc 4+ near an AM radio with a standard ferrite bar antenna is quite a treat. Whereas the L4 and LSH-P just produce a minor hash similar to white noise, the 4+ is rich with switching noise. You can tell there's a micro onboard!

Also, the PWM is quite noticeable (to the naked eye) on L16. Especially when the light is waved around.

I have a nice photovoltaic sensor that I can hook to my board to capture these modulations to PCM (wav) format and can upload some samples for people to listen to if there is an interest. These samples would be from the actual light emission and not from a radio receiver. I have a feeling the later would be more interesting. The PV sensor has excellent attack and decay response times but the LS is relatively slow especially on decay due to the secondary phosphorescent persistence characteristic that all white LED's possess.


Cheers!

/ubbthreads/images/graemlins/ooo.gif

I wanna hear it.

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Also, the PWM is quite noticeable (to the naked eye) on L16. Especially when the light is waved around.

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i can see it better when the light is still than when it's being waved around. maybe i'm waving it the wrong way... should i point the light at my eyes or at a white wall or something when waving? /ubbthreads/images/graemlins/grin.gif

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i can see it better when the light is still than when it's being waved around. maybe i'm waving it the wrong way... should i point the light at my eyes or at a white wall or something when waving?

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Try looking at it while crunching on hard food like a fresh pretzel!

Cheers!

Look at the light at level 16 and wave it in front of your face as fast as you can without losing it. When I mean fast, like you are trying to shake apart the light. Instead of a constant line or an arc of light you will see the LED in focused dots like a string of pearls. You won't see anything just waving like your waving to someone goodbye. You got to really shake it.

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Look at the light at level 16 and wave it in front of your face as fast as you can without losing it. When I mean fast, like you are trying to shake apart the light. Instead of contant line or an arc of light you will see the LED in focused dots like a string of pearls. You won't see anything just waving like your waving to someone goodbye. You got to really shake it.

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Hey, that's a neat trick! It works, and I don't even have to shake it that hard to see it.

BTW, mine is completely silent.

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sharkeeper wrote:

Try looking at it while crunching on hard food like a fresh pretzel!

Cheers!

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What does that do?

I just listened to my Arc4+ and heard a little old lady saying, "Don't go into the light".

All I know is that everytime I point this thing out the window, little grey men with big eyes land in my yard and kill all the grass that I've worked so hard to plant. Then they have the nerve to paralize me long enough to try and steal my Arc4. Luckily, I'm always in the brightness menu when this happends, and just as they try to snatch my Arc4 with their bony little arms the Arc4 drops out of the menu and gives the error blink (high, low, high, low)! This scares the crap out of them little bug eyed buggers! I hear them in my head saying "How did he do that!? He's paralized"! Then, unable to scream because of their tiny slit for a mouth won't open far enough, they disappear leaving only stange shaped depressions in the ground and leave me with a odd pain in the rear.

Peter, what is wrong with this Arc4! I think you got the SOS signaling a bit off, or is it the RF emissions? I didn't see anything about this in the FAQ!

/ubbthreads/images/graemlins/mad.gif

Watch out for the triple-click while standing on one foot and twirling you left hand over your head.......... it activates the "full body cavity search" function.

I cant hear anything. Is it because it is actually ARC4 second? /ubbthreads/images/graemlins/smile.gif

/ubbthreads/images/graemlins/hahaha.gif /ubbthreads/images/graemlins/yellowlaugh.gif

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What does that do?

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Considerable energy is suddenly released when you crunch something hard in your mouth. Since your skull is connected quite well to your jaws, the vibrations get transferred to your eyes and the effect is like moving real fast for short excursions.

Try this while looking at a FL display on a microwave oven or VCR. You can often catch the blank (OFF) time and it appears that segments are burnt out briefly as these (any many other things in your house) are not CW driven devices.

The easiest way to view this is with a camcorder in camera mode. Adjust the shutter speed and look at the display or through the viewfinder. Have fun.

Cheers!

Inductor sing, PWM strobe and some RF emissions are normal across all models of the Arc4.


Peter

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Inductor sing, PWM strobe and some RF emissions are normal across all models of the Arc4.

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Peter, unlike the Eternalight (I have like the first one made LOL) the strobing at L16 is very, very slight. As a matter of fact, the flicker is less noticeable than a monitor running at 60Hz. Of course this depends on phosphor persistence, etc.

I guess a more valid comparison would be the common NE-2 glow lamp running at 60Hz. You can see flicker if you move or blink while looking at it out of the corner of your eye, etc.

I haven't noticed this at higher levels with my eyes.

One thing I did notice at L16 when moving the light real fast is it appears like morse. 7 flashes and a break then 7 flashes repeating.

This light is very cool. This reminds me of when I first received my Eternalight. Of course this doesn't look like I'm carrying around a pack of smokes in my pocket and is way brighter and far more durable. Kudos to (the) design work!

Cheers!

sharkeeper: i noticed that too /ubbthreads/images/graemlins/smile.gif (the rapid flashes and periodic break)

Hay, neat. Opps. Have to go -- men in white jackets coming. /ubbthreads/images/graemlins/tongue.gif

Try using your AM radio, and moving it not by the anttenna, telecoping antenna, but the ferrite bar inside. You may have to try various areas around the radio if you don't know where it is. Also, try down at the lower end of the AM band, and put it inbetween stations. Then you should be able to really hear it sing.

For some folks, it is completely overwhelming, and causing a complete loss of local stations. Think 50,000W 4 miles away.


Lets hear your ARC4, is it singing, does it purr, is it angry, does it growl, does it groan?

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For some folks, it is completely overwhelming, and causing a complete loss of local stations. Think 50,000W 4 miles away.

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If Peter sells enough of these the airlines may have to change their announcement to add ARC4 users in their statement regarding the use of electronic devices!

Cheers!

Ok here are some sounds for you to listen to.

To make this as simple as possible and easier for those not blessed with a broadband pipe, I have broken these down into individual sound files. The first group was recorded directly from an AM radio tuned low in the band in the 450 meter range. There is just some typical buzzing interference in the background.

First the ARC 4+

During this clip the light was turned on and cycled through primary, secondary and minimum brightness levels. The locator beacon is ON so when it is turned OFF you can hear the chirping of the driver. I turn it back on and get into options. Those of you familiar with these menus can probably recognise what the light is doing.

Surefire L4

This is rather quiet activity-wise but packs a wallop of a signal! This would make a good noise generator! The radio picks it up well even 1 meter away! Amazing. No switching or electronic noises however.

The ARC LSH-P

Much quieter and just a slight change in RF probably from component drift as they warm up.

The Eternalight

Obviously we expect to hear more action as this is a microprocessor controlled light. The ARC 4 emits more signal despite the aluminum case though. Eternalight owners can probably figure out what the light is doing by listening carefully as well.

Bruan Razor

Ok, it's not a flashlight but is microprocessor controlled. This is obvious!

Part 2.

The light ouput modulation.

I didn't record the Surefire or ARC LS because they don't have any superimposed modulation of the output. The ARC 4+ does and (not surprisingly) sounds strikingly similar to the RF received noises.

A simple photovoltaic converter (used for measuring power output of lasers) was connected to a board that fed the recording equipment. The output sounds noisy because the levels were limited to prevent overload on the mixer input. Normalising to 0 dB increased the noise but you can clearly hear what the light is doing.

The A/C hum in the beginning is actually from ambient light from an overhead fixture being picked up. It's a Philips Earthlight CF and the light has A/C on it. Not nearly as bad as a tar ballast driven FL or HID but you get the idea.

ARC 4+ Light Noise

You hear the locator beacon pulse. I turn the light on, cycle through primary, secondary then triple click to go to L16. Shut off light, click rapidly and let go to access through menu. You hear the cycle through SOS, TAC, FINDME, RFS. I let RFS go then err out.

As long as it NEVER sounds like this!!!

Pretty neat stuff.

Cheers!