EMI -- IMPORTANT - READ THIS

[resago]

I have a pond master mag drive model 5.
I have been having problems with unreal tournament not running good at resolutions over 1024x768x32. I have a geforce 3 asus 8200 deluxe, so I knew something was wrong. I also had notice a flickering of my monitor seemingly at the same pulse rate as the sound from my pump.

I finally decided to try something. I had an old power supply lying around. I took the screws out of the PS and took the U-channel top and placed it over my pump in my computer case.

result-
monitor flicker is much less noticable and now UT runs at 1600x1200x32

I may try wrapping the pump in aluminum foil to further try to reduce the EMI.

[Joe]

EMI is a bitch.

RFI is also a pain, if you use Cold Cathode inveterters, or Neons (which have internal inverters), it can create enough RFI in your case to screw with DD5 thermal probes! I have seen a 4Deg C difference in the probes reading between the Neons on and off.

[resago]

I think the EMI was screwing with my system clock which destroys the entire systems performance.

I suppose someone needs to make a modified shielded pump specifically for computers.
Mr. Huck?

say like a mag drive 3 or ehiem 1250 with custom metal shell with ground strap.

[LiquidCool]

Will that be cash or charge?

Seriously, tell me what you want... My email and site is in the sig... ICQ is 95735580

[hielko]

The eheim 1250 pump is shielded by default .

[bdunosk]

Someone else was talking about EMI with their Danner pump that was a Pondmaster. He took it back and got something else, that was also a Danner Magdrive 3 (I believe) but it had no EMI interference. I could have sworn it was this forum, too - I guess Pondmaster, though it's almost the exact same thing as the regular Magdrive, creates a lot more EMI?

[hmorgoth]

On behalf of all i know i would like to say the thoughts of many in the UK are with those famileys who lost loved ones on the 11th. and hope the culprets are caught and what little justice that can be done for such a terrable crime can be done!!___________________________________________

I have used TWO Mag drive pumps And both cause my screen to flicker at over a foot in distance! need to get some lead!!!! :-)

[LiquidCool]

From what I have heard the pondmasters have more EMI than the normal magdrive models. Since it is a PONDmaster it is supposed to be outside so it has less sheilding.

The normal aquarium pump models have more sheilding because they are inside...

[redleader]

Yeah inside pumps like my Eheim produce very little external magnetic field. I can hold it in physical contact with my TV and there is no distortion at all. Pretty nice for a 317GPH pump.

[resago]

I just hate the thought of draining my system and having to refill it.

I run an inline system and its a bitch to fill. takes like 3 straight hours, I usually throw Tremors into the DVD player while doing it. I probably know every line of Tremors I and II.

[LiquidCool]

You need to buy some new DVDs, or at least to DL some new ones...

[resago]

Tremors is a classic.

[Kevin]

When putting a subwoofer next to a CRT, the CRT monitor gets all crazy looking. What kind of effect is that?

[Butcher]

That would be EMI - the magnetic field from the sub woofer speaker coil and fixed magnets causes the electron beam in the crt to bend toward it which causes picture and colour distortion.
It happens with all speakers though speakers for computers are normally shielded.

[Nordic]

Kevin, a tip:
EMI = "ElectroMagnetic Interference"

And what is that subwoofer of yours? It's an electrodynamic loudspeaker that is based on the principle of electromagnetic induction. Okay so we have induction but what makes the voice coil move? A big powerful permanent magnet.

[resago]

ok, check out my Uber 31337 shielding job.

[resago]

not sure that it made much difference, but now my pump looks like a baked potato with hoses shoved into it.

[Sanjuro]

Hmm.. would that help? I know that aluminum doesn't have magnetic properties... the EMI would most likely just emit right through.

[Butcher]

magnetism isn't the issue as something ferrous would just become magnetised by the EMI which would be worse. Nickel is the normal shielding material, you can get nickel paints designed for painting inside boxes for shielding

[WaterPog]

just tell anyone who asks that you modified one of those "potato clocks" to power your computer.....

[iceheart]

Get an EHEIM, mine doesn't interfere with the screen even when I press it flat to the glass.

[resago]

I'd be willing to pay $30 + shipping for a wrap-around metal/nickel shield with snap on or screw on front and back plate for my pump, and as I understand it, it would fit any danner mag drive pump.

I've already laid down the cash for this pondmaster, so if I can get a good shield for around $35 I'll be happy.

space around my pump is serverly limited, so the shield would really have to hug the pump in most of its dimensions.

Micheal, blade, any takers?

[Strafe]

Yikes! RFI from a cold cathode, I hadn't thought about that! Is it just the inverter that does that? Can it be shielded?

[redleader]

Al won't help. Its reluctance is about the same as air IIRC. So its not really useful. As for Iron, I disagree. It would become magnetised itself, but it would also draw much many more flux lines into it from the surounding air. At least thats how I understand it from working on a coilgun.

I asked an engineer (designs PC power supplies for a living) about this, he recommended permalloy from the McMaster catalog.

[Butcher]

I have my neon inverter off cos of the really annoying 4KHz whine it puts out not the RFI, maybe some shielding and noise proofing is needed