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Re: nema17 dampers

Posted: Sun Sep 06, 2015 7:01 pm
by jdacal
Thanks Ed and Tim,

There is a 12 volt input to the card from the power supply correct? Am I ok just tapping off of that and running 12volts to each fan?

Re: nema17 dampers

Posted: Sun Sep 06, 2015 9:01 pm
by ednisley
jdacal wrote:a 12 volt input to the card from the power supply
Only if you have the old 12 V heated bed. If you have a pure 24 V system, there's no +12 V supply to be found...

A "buck converter" is dirt cheap in onesie-twosie quantities delivered halfway around the planet:
http://www.ebay.com/sch/i.html?&_nkw=buck+converter

Wire it up to 24 V, twiddle the trimpot until it delivers 12 V, connect the fans, done!

That'll give you a fan that runs at full speed. PWM control of a buck supply definitely won't work, but you can turn it off and on by connecting the buck supply to whatever fan output you're using, then use PWM 0 and PWM 255 to switch the power.

However, for a dollar apiece, get three or five converters, because you might run into the same quality control issues I have:
http://softsolder.com/2015/01/07/dc-dc- ... r-qc-fail/

Image

http://softsolder.com/2013/11/11/arduin ... lder-fail/

Image

Re: nema17 dampers

Posted: Sun Sep 06, 2015 9:11 pm
by Dale Reed
Assuming that is the corner near pin 1, I can see your quality issue clearly: heck of a solder joint (or lack thereof) at pin (n-2). Not too good on the one next to that. Somebody's reflow oven needs some tuning in the temperature control area... :-(

Re: nema17 dampers

Posted: Sun Sep 06, 2015 9:47 pm
by jdacal
Thanks Ed, great tip. Will order tonight.

Re: nema17 dampers

Posted: Mon Sep 07, 2015 2:04 am
by Tim
ednisley wrote: A "buck converter" is dirt cheap in onesie-twosie quantities delivered halfway around the planet:
http://www.ebay.com/sch/i.html?&_nkw=buck+converter
Ed, you are truly a vast source of knowledge. Clearly there's no point in rigging up a bit of vectorboard with a regulator and capacitors and all that when you can get one of these already made for 90 cents. It just blows the mind. The individual components are at least $5 on Digi-key. Clearly the Chinese can get these things at bulk rates that I can't even imagine, and can assemble them and ship them back to the U.S. and still be below the price I can get the components for. When they learn to build chips the same way, I'm out of a job. . .

The page you referred to has about 50 different items on it; I suppose that one of those basic $1 boards with just an LM2596, electrolytic caps on input and output, and a potentiometer will do the job?

I love eBay's keyword-based sponsored links. You put in "buck converter" and at the bottom you get a link for "Men's Buck Naked Performance Boxers". . .

Re: nema17 dampers

Posted: Mon Sep 07, 2015 3:44 am
by jdacal
I ordered 10 pack of these from US. Don't want to wait for China, sometimes its quick sometimes it takes forever.

http://www.ebay.com/itm/10pcs-LM2596S-D ... 1e88ca6aab

Re: nema17 dampers

Posted: Mon Sep 07, 2015 4:03 am
by Tim
jdacal wrote:I ordered 10 pack of these
If you happen not to need 10 of them, send me a PM when you get them; I'll buy a couple off of you.

Re: nema17 dampers

Posted: Mon Sep 07, 2015 5:47 am
by jdacal
Tim wrote:
jdacal wrote:I ordered 10 pack of these
If you happen not to need 10 of them, send me a PM when you get them; I'll buy a couple off of you.
Sure Tim, will send you a few. I'll contact you when I get them.

Re: nema17 dampers

Posted: Mon Sep 07, 2015 4:28 pm
by ednisley
Tim wrote:no point in rigging up a bit of vectorboard
As nearly as I can tell, the Chinese electronics industry has built everything in the Sparkfun and Adafruit catalogs (Open Hardware, don'cha know), strip-mined every semiconductor App Note ever written, and reverse-engineered all commercially available products that fit on four square inches of PCB.

It's the Golden Age of hardware hacking, but only because you can start with surprisingly large building blocks of dubious provenance. After you figure out the proper keywords, it's all out there somewhere.

The part I don't understand: the as-delivered cost adds up to less than the postage to return a DOA part. There must be a massive subsidy propping up that business model, but I cannot follow the money.
a link for "Men's Buck Naked Performance Boxers"
The "you might also be interested in ..." algorithm sometimes delivers more amusement than value!

Re: nema17 dampers

Posted: Mon Sep 07, 2015 5:02 pm
by helifrek
I am ready to take the plunge, does anyone in the US have two extras they would be willing to part with?