Fixing a PWM DCC Fan Controller
Instructor
Joined: Oct 2005
Posts: 103
Likes: 0
Just because someone is uneducated doesn’t make them a fool, they’re not fools and they already understand, so speak for yourself.
The answer to that question should be pretty obvious, none of us owe you the time of day, and I’m certainly not going to again give you the opportunity to muddy the waters with your rhetoric. Your offered advice has resulted in an order of magnitude more demolished Spal controllers than my own, and it’s no coincidence that the one controller that survived was connected per the manufacturers instructions anymore than it’s a coincidence that the one controller of mine connected per your direction was destroyed. Perhaps they would be willing to waste their time with you, but I doubt it, and I certainly won’t
The explanation has already been provided, and most people, with the exception of yourself understood it. So, given you in reality have never done anything more technical than an internet search, seem to consistently give bad advice, and don’t even own one of these controllers, how does anyone here owe you an explanation for anything?
The answer to that question should be pretty obvious, none of us owe you the time of day, and I’m certainly not going to again give you the opportunity to muddy the waters with your rhetoric. Your offered advice has resulted in an order of magnitude more demolished Spal controllers than my own, and it’s no coincidence that the one controller that survived was connected per the manufacturers instructions anymore than it’s a coincidence that the one controller of mine connected per your direction was destroyed. Perhaps they would be willing to waste their time with you, but I doubt it, and I certainly won’t
Melting Slicks
Joined: Dec 2005
Posts: 2,441
Likes: 0
You might think of it like if you were to overdrive a speaker and it blows, you can't point to the fuse protecting the amp and say it should have blown to prevent this from happening. I think you may just need to chalk it up to experience.
Last edited by shafrs3; Oct 15, 2007 at 07:08 PM.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Just because someone is uneducated doesn’t make them a fool, they’re not fools and they already understand, so speak for yourself.
The answer to that question should be pretty obvious, none of us owe you the time of day, and I’m certainly not going to again give you the opportunity to muddy the waters with your rhetoric. Your offered advice has resulted in an order of magnitude more demolished Spal controllers than my own, and it’s no coincidence that the one controller that survived was connected per the manufacturers instructions anymore than it’s a coincidence that the one controller of mine connected per your direction was destroyed. Perhaps they would be willing to waste their time with you, but I doubt it, and I certainly won’t
The answer to that question should be pretty obvious, none of us owe you the time of day, and I’m certainly not going to again give you the opportunity to muddy the waters with your rhetoric. Your offered advice has resulted in an order of magnitude more demolished Spal controllers than my own, and it’s no coincidence that the one controller that survived was connected per the manufacturers instructions anymore than it’s a coincidence that the one controller of mine connected per your direction was destroyed. Perhaps they would be willing to waste their time with you, but I doubt it, and I certainly won’t
WHICH I may have to assume is that you really don't HAVE an answer, just an anicdotal sample, with NO solid engineering basis to your position....specifically as to WHIT, WHY am I rong???? untill you can esplain that, Lucy, you are off base.....
what is so fragile about PWM controllers that a bit of inductance on the input makes the thing smoke,?? given it has nothing BUT inductance on the load side??? show me the scope patterns, show me something but insults.....you simply have NOT explained what's going on.....
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
NOW you really are into a subject I know like back of my hand.....
any amp driven into clipping puts out a horrendous amount of very hi freq power, far more than any average audio signal, and as such blows tweeters quite readily.....sometimes tweeters are fused, depends on the speaker system mfgr.....the olde tyme vacuum tube daze had large transformers in the line, which along with the tubes did not allow passage of that sort of signal to destructive levels.....typically....there were exceptions, but fairly rare.....but with solid state devices.....it's an across the board problem.....
OH, BTW, many devices are protected from blowing by fuses, or better INTERNAL DESIGN....such as audio amps....first among makers to do this as part of internal design was McIntosh.....surely copied a lot by others today....
but to return to fans, and controllers, I still fail to see just why hooking closer to the alt than the bat makes any differance........
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
ANSWER THE FREEKING QUESTION......or leave with your tail between your legs......
Instructor
Joined: Oct 2005
Posts: 103
Likes: 0
have fun guys, I've got to get back to work
mr vette, try to keep yourself from drilling holes in womens tires, I realize that it's a classy move, but it's also against the law
http://forums.corvetteforum.com/show...1%2F4+inch+bit
mr vette, try to keep yourself from drilling holes in womens tires, I realize that it's a classy move, but it's also against the law
http://forums.corvetteforum.com/show...1%2F4+inch+bit
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Look in many high dollar custom built guitar tube amplifiers and you will see potting and other types of epoxys covering certain parts of the circuit board.
Dumble and TrainWreck Amplifiers, to name just a couple.
I wouldn't ask Picasso how he paints and I wouldn't expect Howard Dumble to explain his circuitry to me either (thats why he hid it) bit if he told me to hook up HIS amplifier to a 4 ohm load rather than the normal, more sensible 16 ohm load I would have took his advice as he was the creator.
If I hooked it up wrong and it fried I would only blame myself.
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Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Many many electronic builders will not divulge the components or circuitry used in their products for obvious reasons.
Look in many high dollar custom built guitar tube amplifiers and you will see potting and other types of epoxys covering certain parts of the circuit board.
Dumble and TrainWreck Amplifiers, to name just a couple.
I wouldn't ask Picasso how he paints and I wouldn't expect Howard Dumble to explain his circuitry to me either (thats why he hid it) bit if he told me to hook up HIS amplifier to a 4 ohm load rather than the normal, more sensible 16 ohm load I would have took his advice as he was the creator.
If I hooked it up wrong and it fried I would only blame myself.
Look in many high dollar custom built guitar tube amplifiers and you will see potting and other types of epoxys covering certain parts of the circuit board.
Dumble and TrainWreck Amplifiers, to name just a couple.
I wouldn't ask Picasso how he paints and I wouldn't expect Howard Dumble to explain his circuitry to me either (thats why he hid it) bit if he told me to hook up HIS amplifier to a 4 ohm load rather than the normal, more sensible 16 ohm load I would have took his advice as he was the creator.
If I hooked it up wrong and it fried I would only blame myself.
Well, actually that would be the other way around....4-16 ohm loading per above, actually.....
35? years ago I bought a Bob Carver of Phase Linear fame 700 power amp, the old A model...first one out....
it was fine at 350 watts/channel into 8 ohms.....
hated 4 ohms though....it blew up BIG TYME.....the smoke was horrendous.....but that was in '88, I tried altering the design, but a buddy made me an offer I couldn't refuse, so bought me present Mac amp, ....
Knowing Ken, I bet he still has it....
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Tube amplifier output transformers don't mind an impedance mis-match as long as the load is higher than the rated winding of the transformer.
The only side effect will be a lower overall output and possible tonal difference. But higher into lower is asking for a blown output transformer and thats what I was referring to in my previous post.
Thats all beside the point anyway as many here may not understand it and probably don't care to.
It' all about the builders design and his decision to divulge the components, circuitry or theory behind it and following their installation instructions.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Not quite, the 4X12 cabinets used were loaded with four 16 ohm speakers wired in series/parallel yielding a 16 ohm rating.
Tube amplifier output transformers don't mind an impedance mis-match as long as the load is higher than the rated winding of the transformer.
The only side effect will be a lower overall output and possible tonal difference. But higher into lower is asking for a blown output transformer and thats what I was referring to in my previous post.
Thats all beside the point anyway as many here may not understand it and probably don't care to.
It' all about the builders design and his decision to divulge the components, circuitry or theory behind it and following their installation instructions.
Tube amplifier output transformers don't mind an impedance mis-match as long as the load is higher than the rated winding of the transformer.
The only side effect will be a lower overall output and possible tonal difference. But higher into lower is asking for a blown output transformer and thats what I was referring to in my previous post.
Thats all beside the point anyway as many here may not understand it and probably don't care to.
It' all about the builders design and his decision to divulge the components, circuitry or theory behind it and following their installation instructions.
Last design without impedance taps on an output xfmr was my old '72 vette radio here.....I think??
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Burning Brakes
Joined: Feb 2006
Posts: 1,173
Likes: 5
From: Paducah Ky
I have read two threads on this subject, one where Matt tried to buy another unit and this one where he tried to get someone to fix the one he has. In neither one did he call out the vendor or bad mouth them in any way. The vendor could have refused warranty based upon improper installation but instead chose to rant on and on here on this forum. The only thing I have learned from all of this BS is that I want no dealings with Brian and his attitude
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Transients in an Automotive Environment
Here is an app note that might help some of you guys who are into self abuse. 
http://www.industrologic.com/autotransients.pdf
Cliff note for you guys that aren't
Connect your power source sensitive electronics to the battery for optimum protection against failure.
Bullshark
Oh, BTW Load Dump transients also occur on our older Automotive power systems when heavy loads are switched off without disconnecting the battery although their magnitude and duration will be lower. These transients are capable of destroying semiconductors on the first 'fault event'.
Also did you guys see the transient levels that can be present with Inductive-load switching (i.e. turning the Dual Spal dc fan motors off and on)? -300 to +80 volts.
http://www.industrologic.com/autotransients.pdf
Cliff note for you guys that aren't
Connect your power source sensitive electronics to the battery for optimum protection against failure.
Bullshark
Oh, BTW Load Dump transients also occur on our older Automotive power systems when heavy loads are switched off without disconnecting the battery although their magnitude and duration will be lower. These transients are capable of destroying semiconductors on the first 'fault event'.
Also did you guys see the transient levels that can be present with Inductive-load switching (i.e. turning the Dual Spal dc fan motors off and on)? -300 to +80 volts.
Last edited by Bullshark; Oct 15, 2007 at 11:55 PM.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Here is an app note that might help some of you guys who are into self abuse.
http://www.industrologic.com/autotransients.pdf
Cliff note for you guys that aren't
Connect your power source sensitive electronics to the battery for optimum protection against failure.
Bullshark
http://www.industrologic.com/autotransients.pdf
Cliff note for you guys that aren't
Connect your power source sensitive electronics to the battery for optimum protection against failure.
Bullshark
In "Cliff's Notes" terms, how does connecting closer to the battery suppress power fluctuations? I can see how having a suppressor of some sort in-line would have that effect, but it seems strange to get the same effect without an in-line device. I only have a lowish-grade hobbyists understand of electronics, and this whole situation is making my head spin.
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Bob,
In "Cliff's Notes" terms, how does connecting closer to the battery suppress power fluctuations? I can see how having a suppressor of some sort in-line would have that effect, but it seems strange to get the same effect without an in-line device. I only have a lowish-grade hobbyists understand of electronics, and this whole situation is making my head spin.
In "Cliff's Notes" terms, how does connecting closer to the battery suppress power fluctuations? I can see how having a suppressor of some sort in-line would have that effect, but it seems strange to get the same effect without an in-line device. I only have a lowish-grade hobbyists understand of electronics, and this whole situation is making my head spin.
Bullshark
Last edited by Bullshark; Oct 16, 2007 at 12:04 AM.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
First off get the abbreviation right PWM as in Pulse Width Modulation, can you say that? PWM controllers use a transistor switch that is cycled on/off at varying rates increasing the current to the itme being controlled. You probably had a transistor failure and from the looks of the area you circled it looks to be "potted" in epoxy. Maybe you can open the unit up and see if there is access. The transistor would be easily found at a decent electronics supply house (probably not Radio Shack.) You could have also destroyed the timing or driver circuit and that fix would be way more difficult. My recommendation: THROW IT INTO THE GARBAGE AND BUY A NEW ONE but find out if your fans are the cause of the failure before frying the next one. I put a premium on time over money on items under $100 but, I'm not you so good luck.