Sizing a capacitor?

--- It's merely being polite and considerate of your readers, something you obviously feel to be unimportant or which you refuse to consider because you feel it's too much like following orders and you'll be _damned_ if you'll let that happen.

-- JF

Fair point, though I disagree. There are only two regular posters on the entire Usenet whom I would describe as thoroughly nasty, to a pathological level. (Maybe they're the same person, even :) ). I do know many many Usenet users have killfiled them/him to avoid it, and that those are somewhat miffed by seeing it quoted and so getting "through the barrier" as it were. So I'm not alone. My skin is pretty thick too...

Yes, well I suppose I meant in those newsgroups I frequent!

Yep, pruning the quoted text is also good. And often lacking in this group.

I think that some of the posters would benefit from switching to Pan; you get a warning dialog if the "message is mostly quoted text" (and also for "some lines are more than 80 columns wide" and "crossposting without setting Followup-To").

Maybe you missed the "If you are replying protesting at ..." part?

Presumably someone who is protesting at a post already disagrees with the tone. In which case, why reproduce it verbatim?

In cases where this happens, it isn't necessarily a conscious choice, but an oversight in the heat of the moment.

I see no problem in Suzy asking people to actually consider whether to quote the text verbatim, rather than doing so just because that's what you always do when you reply to someone.

Please, I need help. I just ran 12v straight to the fan and it ran on high. No problems with interference. With that out of the way, I decided to not put those magnet things on the motor wires. However, I did put them on all the wires from the water/meth controller with no luck. Its strange that the controller works fine when the fan is on high and medium, but only interferes when the fan is on low.

soon enough!

soooner

achtung! been there , done it. no more!

any improvement when run straight at 12v? whats different?

is the fan air flow affecting anything? wire shake/air flow elsewhere/sensors?

you are doing the right thing as you eleiminate each "good" condition, make sure to write it down in some form, at least to keep track of what works,& what doesnt too

wish u were close enough, i'd come over and try to help.

--- You really _should_ leave enough of the message you're replying to intact in order to let whoever reads your moronic, self-serving posts know what you're talking about.

-- JF

--- You really _should_ leave enough of the message you're replying to intact in order to let whoever reads your moronic, self-serving posts know what you're talking about.

-- JF

--- You really _should_ leave enough of the message you're replying to intact in order to let whoever reads your moronic, self-serving posts know what you're talking about.

-- JF

I need to see more details about how the fan speed control mechanism is wired. Evidently it is the speed control that is causing th noise, not the motors. The noise is probably coming from the speed controller producing fast edged pulses of 12 volts to the motors. The ferrite beads might work, but they would have to be placed near the controller to contain its noise. And it may help to put a capacitor across the 12 volt supply lines feeding the controller, so its pulses don't bleed back into the 12 volt distribution.

(snip)

(snip)

For instance, it will make a big difference in the fan wiring spreading interference if the controller has a pair of wires feeding the motors, of it it has only 1 wire feeding the motors, with the other terminal of the motors is connected to the nearest ground.

OK, I think I have it visualized as to what you're doing.

You have a PWM drive and it isn't connected directly to the terminals of the motors ? Assuming this is correct, in effect, you are radiating strong EMF waves under the hood. Adjacent wiring is becoming an R.F. receiving transformer and there for, influencing the lines of other equipment.! Especially things that have low current sensor transmission lines will mostly be whacked.

What you need to do is have the output of the PWM circuit pass through an inductor circuit with a smoothing cap on the other side.

for proper size selection, knowing the carrier frequency of the PWM circuit helps.