Sizing a capacitor?
serpa4
about electronics. However, maybe someone here can help. I replaced
my engine driven fan on my 2007 GMC with a set of electrics fans that
are wired through a 30 amp fuse for each of the two fans. However,
the fans are messing up my water/meth injection controller. The water/
meth controller pumps a mix of water/meth into my intake manifold
based on turbo boost. When my electric fan kicks in, the controller's
reading for boost and the temperature of the exhaust on its LED
display go to zero. The display still works/lights up etc, and
displays text, but just reads zero for boost and exhaust gas
temperature (EGT). I have a mechanical turbo boost pressure gauge and
a mechanical temperature gauge for the exhaust also. These, being
mechanical, keep working fine. If the truck is making 10 lbs of boost
then the cooling fans kick in for the radiator, the boost and EGTs
drops to zero. When the fan stops, the boost and EGT readings return
from zero to whatever they should be (10 psi/800 degrees). The boost
is picked up via a plastic tube and routed to the water/meth
controller which is digital in nature. The electric fans are
controlled by a pulse width modulator to allow for a variable speed
setup. The fan controller is mounted to the radiator's metal cross
member. I have two batteries in my truck. To further isolate the
water/meth controller from interference, I completely removed the +/-
of one battery and ran both the ground and positive wire from the
water/meth controller and its injection pump to the isolated battery
for power and ground. Nothing in the water/meth controller or pump
setup touches the truck or the truck chassis and it still stops
working when the fan turns on. For more trouble shooting, I have
trapped 4 psi of air in the controller tube for trouble shooting
purposes. So, the gauge always reads 4 psi weather the truck is
running or not so I don't have to actually drive to make turbo boost.
However, the instant I connect the fan and the fan turns on, the boost
and EGT readings go to zero. Unplug the fan or turn them off, the
boost and EGT readings comes back. I'm guessing is the problem is RF
noise. How do I stop this? I don't know anything about capacitors.
However, back in my youth, the electric motors in my radio controlled
cars ran capacitors on the motors to keep from interfering with the
radios. Please don't use technical stuff like thin film or what ever,
which means nothing to me. What I'm looking for is:
Hey, put a 100 whatever capacitor between the + and - of the motor and
see if that helps. The fans are both wired to a 30 amp fuse, so I
guess the capacitor needs to be 12 v and handle up to 30 amps? Just a
guess. Thanks to anyone who can help.
Also, tonight I made a very strange discovery. The fan is multi speed.
When the fan is on low, the controller functions as stated above,
messes up the water/meth controller. HOWEVER, when the fan switches to
medium speed, the boost starts working again. Here is the funny
part..........
When the fan switches from low to medium, the MECHANICAL boost gauge
(not the one built into the water/meth controller, goes up by up to
SIX psi instantly. The turbo has veins that move to change boost and
are controlled by the truck's computer. I can hear the turbo spool
and my butt can definitely feel a slight pick up in acceleration. So,
at cruising speed of about 65mph and the turbo making about 5 psi
boost on the mechanical gauge and the fan is on low, the water/meth
controller is not working... then the fan kicks to medium, and the
controller starts working, and the mechanical boost gauge raises to 11
psi. This is a real gain in boost from the feel and from hearing the
turbo. Its not extra horse power from the water/meth since it is not
injecting AND the pump is disconnected anyway for trouble shooting.
When the fan drops to low, the water/meth controller stops reading,
and instantly the boost on the mechanical gauge drops back to 5 or
so. What do you all think? Some thing isn't right here. How can the
fan cause the boost to change unless it's also messing with the truck
computer and not just the water/meth controller? The fans have their
own temperature sender unit in the upper radiator hose and don't
interface with the factory computer in any way.
I cannot return either unit since they were installed.
Eeyore
serpa4 wrote:
> Hello. 1st post on any group.
Before you post any more, may I recommend the use of paragraphs to break up up
acres of solid text. I find it virtually unreadable.
Graham
Jamie
I would check for lack of ground straps.
it sounds like you are created a current path through the
engine block or radiator etc. the Sensors of the electronics
for the controller maybe getting nulled out.
--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5
Roger Dewhurst
"serpa4" <lorne...@comcast.net> wrote in message
news:1193695577.0...@e9g2000prf.googlegroups.com...
Run all the circuits off separate relays.
R
>
John Popelish
> Hello. 1st post on any group. Hope this works. I don't know squat
> about electronics. However, maybe someone here can help. I replaced
> my engine driven fan on my 2007 GMC with a set of electrics fans that
> are wired through a 30 amp fuse for each of the two fans. However,
> the fans are messing up my water/meth injection controller.
(snip)
> What do you all think? Some thing isn't right here. How can the
> fan cause the boost to change unless it's also messing with the truck
> computer and not just the water/meth controller? The fans have their
> own temperature sender unit in the upper radiator hose and don't
> interface with the factory computer in any way.
> I cannot return either unit since they were installed.
Either the fan brushes or the speed control (probably a
variable pulse duty cycle driver) are making radio frequency
hash that is upsetting other sensitive electronics. Either
you filter the fan wiring or you filter all the things that
are being upset. I would start with the fans.
Look for one or a few clip on split ferrite bead that can be
snapped around both fan leads (close to the fans). These
will reduce the high frequency currents that travel back
from the fan to the rest of the wiring harness and radiate
all over the place.
The ones with a hole just large enough to pass the pair of
wires will be most effective. If you can only find ones
with a much larger hole, you might be able to wrap the pair
around through the hole for a second pass.
This is what I am talking about:
http://rocky.digikey.com/WebLib/Steward/New%20photos/28A2026-0A2.jpg
If that helps but doesn't solve all problems, you can add
more beads along the wire.
It might also help to add a capacitor across each of the
motors, right at the fan, and also to add one from each
terminal to the motor frame, but that is a lot more invasive
than adding the beads, so it would be my second try.
HapticZ
but shouldnt they be placed on the supply lines going to the PWM circuit
rather than between the fan-pwm? the entire wire length is probably
radiating all sorts of splatter emf everywhere. shortened and even shielded
may help also.
or both places?
if possible, find some tech guy to alter the PWM circuit to prevent such
drastic sharp rise times in the switch circuitry itself?
"John Popelish" <jpop...@rica.net> wrote in message
news:JOCdnR8VVKeKJ7va...@comcast.com...
John Fields
<hap...@sbcglobal.net> wrote:
>agreed, inline filters are good suppressors for the pwm driving the fan,
>but shouldnt they be placed on the supply lines going to the PWM circuit
>rather than between the fan-pwm? the entire wire length is probably
>radiating all sorts of splatter emf everywhere. shortened and even shielded
>may help also.
>
>or both places?
>
>if possible, find some tech guy to alter the PWM circuit to prevent such
>drastic sharp rise times in the switch circuitry itself?
---
Please don't top post.
Even Google Groups advises against it.
From:
http://groups.google.com/support/bin/answer.py?answer=12348&topic=250
"Summarize what you're following up.
When you click "Reply" under "show options" to follow up an existing
article, Google Groups includes the full article in quotes, with the
cursor at the top of the article. Tempting though it is to just
start
typing your message, please STOP and do two things first.
Look at the quoted text and remove parts that are irrelevant.
Then, go to the BOTTOM of the article and start typing there.
Doing this makes it much easier for your readers to get through your
post. They'll have a reminder of the relevant text before your
comment, but won't have to re-read the entire article.
And if your reply appears on a site before the original article
does,
they'll get the gist of what you're talking about."
---
--
JF
serpa4
break up
I would check for lack of ground straps.
It sounds like you are created a current path through the
engine block or radiator etc. the Sensors of the electronics
for the controller maybe getting nulled out.
The engine has a ground strap to the truck fire wall. The fan
controller is grounded to the frame at a pretty good location. With
the problem still there, I tried a new ground location: water meth
controller was powered and grounded to a completely separate battery
directly and the battery was not grounded to the truck.
Should I try a different place? Currently, since completely isolating
the power and ground via a completely separate battery for the water/
meth did not work I have moved the fan controller ground, water/meth
ground, and controller ground back to the radiator mount which is
reported by truck owners as a very good place to ground to.
Run all the circuits off separate relays.
There are no relays that I know of in the system. The water/meth
controller is powered from a key on location for power. It was
powered directly off a completely (second) separate battery. Neither
location had any effect. The fan system doesn't have any relays that
I know of. I believe the controller itself has the switching
mechanism in it.
It might also help to add a capacitor across each of the
motors, right at the fan, and also to add one from each
terminal to the motor frame, but that is a lot more invasive
than adding the beads, so it would be my second try.
I'll try those magnet things. Any chance radio shack or some local
store will carry them or should I order off the internet?
Also, what size and type capacitors should I get? I have no idea.
HapticZ
"John Fields" <jfi...@austininstruments.com> wrote in message
news:vloei31rjsrn3n9d2...@4ax.com...
John Popelish
> using "reply to group", how does that constitute "top post"?
Typing your words above those you are replying to is top
posting.
HapticZ
the msg and then start typing? that will just wear me right out!
or should i set the option to "not include original message"?
"John Popelish" <jpop...@rica.net> wrote in message
news:S6SdnQIyBsHrcLra...@comcast.com...
John Popelish
> so i have to manually move my default cursor all the way to the bottom of
> the msg and then start typing? that will just wear me right out!
>
> or should i set the option to "not include original message"?
You are supposed to review the quoted text and clip out any
parts that is not needed to remind others what you are
replying to, before you post. It is customary to add in
(snip) or 8< (scissors symbol) if you clip the last poster.
Then, you either insert your words directly below lines that
you are reacting to, or post your entire message at the
bottom. This is the standard for Usenet and just good
manners. Remember, this is not an email reply to one person
who knows what they have already said, but an archived post
that is part of a conversation presented to the entire
world, for anyone to join in. Normal capitalization,
spelling and punctuation are also appreciated. It is hard
enough to interpret many posts, without also having to
decode slang and abbreviations. This is not a cell phone
text message.
You are certainly free to do whatever you like, but if you
can't be bothered to think about the effort it takes others
to understand what you write, don't be surprised if many
kill file you and never see anything else you ever post.
Bye bye.
John Popelish
Eeyore
HapticZ wrote:
> so i have to manually move my default cursor all the way to the bottom of
> the msg and then start typing? that will just wear me right out!
Oh dear. Poor baby !
Graham
Suzy
replying to)
"HapticZ" <hap...@sbcglobal.net> wrote in message
news:58SVi.2111$%13....@newssvr22.news.prodigy.net...
Suzy
Well explained John. But there is another point. If you are replying
protesting at foul language or nasty posting (a regular perpetrator of which
appears here occasionally) be careful not to requote his foulness as others
may have kill filed to avoid his nastiness!
John Fields
<hap...@sbcglobal.net> wrote:
>using "reply to group", how does that constitute "top post"?
---
You seem to miss the point, which is that top posting is generally
frowned on when replying to a USENET post, for many reasons.
You do know the difference between top posting, bottom posting and
inline posting, don't you?
Peruse:
http://www.google.com/search?hl=en&q=top+posting
--
JF
John Fields
---
Suzy,
Even though you may find it repugnant to read what you perceive as
"foul language" or "nasty posting", I find it even more repugnant
that you would have others censor others' posts in order to comply
with what your delicate sensibilities dictate is 'proper' behavior.
This is, after all, USENET, arguably the last bastion of truly free
speech on the planet, so if you want to play here and not be
perpetually offended by some of the other players, I suggest you
grow thicker skin. :-)
--
JF
HapticZ
HapticZ
me to death............
John Popelish
> protocol, rigid social levels, strict grammatix, and so forth. just bores
> me to death............
Evidently, not yet.
John Fields
---
One can only hope...
--
JF
John Fields
<hap...@sbcglobal.net> wrote:
---
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
Suzy
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...
John Fields
>
>"John Fields" <jfi...@austininstruments.com> wrote in message
>news:l58hi397hoh1l60jf...@4ax.com...
>> Suzy,
>>
>> Even though you may find it repugnant to read what you perceive as
>> "foul language" or "nasty posting", I find it even more repugnant
>> that you would have others censor others' posts in order to comply
>> with what your delicate sensibilities dictate is 'proper' behavior.
>>
>> This is, after all, USENET, arguably the last bastion of truly free
>> speech on the planet, so if you want to play here and not be
>> perpetually offended by some of the other players, I suggest you
>> grow thicker skin. :-)
>>
>>
>> --
>> JF
>
>Fair point, though I disagree.
---
So you think that you should be the arbiter of what's fit to post
and what isn't and that your guidelines should be rigorously adhered
to?
Would you also assess penalties to violators of "Suzy's rules of
order"? ;)
---
>There are only two regular posters on the
>entire Usenet whom I would describe as thoroughly nasty, to a pathological
>level.
---
Your naiveté astounds me!
Just for two, [groups] have you never visited alt.kooks or soc.men?
---
>(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.
---
Misery loves company? ;)
---
>My skin is pretty thick too...
---
If you're upset to the point where you want to silence them or
modify their behavior because of what you consider to be an
affrontery to _your_ good taste, even when you're not being targeted
by their rancor, then I suggest your skin is still pretty thin and
you either learn to silence them / change their behavior with
incontrovertible arguments or linger in a hot brine bath for some
time.
--
JF
Suzy
Yes, well I suppose I meant in those newsgroups I frequent!
John Fields
---
Aren't you sure?
--
JF
Nobody
>> so i have to manually move my default cursor all the way to the bottom of
>> the msg and then start typing? that will just wear me right out!
>>
>> or should i set the option to "not include original message"?
>
> You are supposed to review the quoted text and clip out any
> parts that is not needed to remind others what you are
> replying to, before you post.
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").
Nobody
>>Well explained John. But there is another point. If you are replying
>>protesting at foul language or nasty posting (a regular perpetrator of which
>>appears here occasionally) be careful not to requote his foulness as others
>>may have kill filed to avoid his nastiness!
>
> ---
> Suzy,
>
> Even though you may find it repugnant to read what you perceive as
> "foul language" or "nasty posting", I find it even more repugnant
> that you would have others censor others' posts in order to comply
> with what your delicate sensibilities dictate is 'proper' behavior.
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.
serpa4
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.
1) Should I put capacitors on the fan motors? If so, what size, type,
etc.
2) What should I try next?
Thanks in advance for any help.
HapticZ
HapticZ
HapticZ
HapticZ
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.
John Fields
wrote:
>On Wed, 31 Oct 2007 10:46:13 -0500, John Fields wrote:
>
>>>Well explained John. But there is another point. If you are replying
>>>protesting at foul language or nasty posting (a regular perpetrator of which
>>>appears here occasionally) be careful not to requote his foulness as others
>>>may have kill filed to avoid his nastiness!
>>
>> ---
>> Suzy,
>>
>> Even though you may find it repugnant to read what you perceive as
>> "foul language" or "nasty posting", I find it even more repugnant
>> that you would have others censor others' posts in order to comply
>> with what your delicate sensibilities dictate is 'proper' behavior.
>
>Maybe you missed the "If you are replying protesting at ..." part?
---
Nope.
---
>Presumably someone who is protesting at a post already disagrees with the
>tone. In which case, why reproduce it verbatim?
---
In most cases, the content which is being complained about must be
left intact in order for the complaint to make sense. For example,
assume that I find your next sentence offensive, so I prune it and
reply to it:
<SNIP>
I disagree with that, and I find it offensive, so I've snipped it in
case anyone who reads this might also find your statement offensive.
Confusing, huh?
Anyone who wasn't familiar with what you'd written would have to go
back a post to find out what you'd said that was offensive (and take
the chance of being offended) just to find out what was going on,
so, just out of courtesy I'd leave all the shits, pisses, and fucks
that you'd written in my reply. :-)
---
>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.
---
I have no problem with that either, but that's not what Suzy was
asking for. What she wants is for everyone to prune what _she_
considers to be offensive material in order that if she happens to
come across a reply to a post which contained material which was
offensive to her she could read the reply without being subjected to
that material.
--
JF
John Fields
wrote:
>soon enough!
---
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
John Fields
John Fields
wrote:
>achtung! been there , done it. no more!
---
John Fields
John Popelish
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.
John Popelish
> serpa4 wrote:
>> 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.
> I need to see more details about how the fan speed control mechanism is
> wired.
(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.
Jamie
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.
--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5
serpa4
Identical.
is the fan air flow affecting anything? wire shake/air flow
elsewhere/sensors?
I've, through trouble shooting, have moved and tied down wires every
where in multiple places with no effect.
wish u were close enough, i'd come over and try to help.
Me to.
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.
No, the beads didn't help. They are about ½ inch or less from the
controller. I don't know how the controller works. Its in a sealed
metal box.
I still don't know what type or size capacitor to use. I'm clueless
on capacitors or what the actually even do.
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 ?
I don't think so. There are several wires going into the controller.
Two are heavy wires (+ and -) from the battery to power the fans I'm
guessing. There is also one other +/- that I think is the PWM
contollers power source.
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.
I don't understand why this is only on low.
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.
I'm clueless about electronics. What you said just went way over my
head.
for proper size selection, knowing the carrier frequency of the
PWM circuit helps.
I have no Idea.
This is the manufacture:
http://www.spalusa.com/