Looking for some Insight - Page 1
Forum section: electronics / beginners

author: Food4MyBrain
author_rank: Newbie
timestamp: May 17, 2019, 09:05:37 pm
content: Hello,What would be the best power supply and potentiometer to use to control the speed of this PC fan?https://noctua.at/en/nf-a14-industrialppc-3000-pwm/specificationI was doing some research online and came across this formula to calculate the ohm rating for the POT. Keep comming up with 30 ohm which doesn't sound right...https://fearless-assassins.com/topic/36138-making-your-own-computer-fan-controller/Any help is greatly appreciated.

author: windsmurf
author_rank: Frequent Contributor
timestamp: May 17, 2019, 11:21:58 pm
content: Sounds right if you assume your fan minimum voltage is 5v. Not sure if that fan you chose require 5v pullup on PWM to work.

author: james_s
author_rank: Super Contributor
timestamp: May 18, 2019, 12:56:03 am
content: Using a potentiometer to directly control the speed of a fan is far from ideal. Why not use a variable power supply, or make a little regulator with a LM317, or one of the numerous dirt cheap buck regulator modules from China, or a PWM fan speed control? Everything you need is available off the shelf for a few dollars.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 18, 2019, 11:59:29 am
content: Quote from: windsmurf on May 17, 2019, 11:21:58 pmThat's a good point. 5v was an assumption. I will have to reach out to Noctua's support department for that information. Thanks for the input windsmurf.Quote from: james_s on May 18, 2019, 12:56:03 amAppreciate the input james_s. I'm a noob master when it comes too electronics. That was the plan at first to get a variable power supply. I was looking at the Mean Well RS 15-12 Enclosed switching power supply. It looks like a promising power supply but, does it have too much current and wattage for the fan. Also the voltage adjustment is minimal 10.8v - 13.2v.https://www.meanwell.com/webapp/product/search.aspx?prod=RS-15

author: madires
author_rank: Super Contributor
timestamp: May 18, 2019, 12:41:35 pm
content: That fan has a connector for 4-wire PWM and is designed for 12V at 0.55A max. To control the speed you might buy something likehttps://noctua.at/en/na-fc1.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 18, 2019, 02:12:25 pm
content: Quote from: madires on May 18, 2019, 12:41:35 pmI feel like a tard. Nice find madires. I was all over that site and didn't see that. The fan is being used for a DIY project so it needs to be powered by a power supply. Is there anyway to do that? And would the Mean Well RS 15-12 power the NA-FC1? It looks like you need 12v and 5v hooked up to it. If that's the case... how would you achieve that? use a resistor on a 12v leg from power supply to drop the voltage?Edit : I think i might be looking at it wrong... The NA-FC1 is powered with 12V on the input and spits out 12v and 5v on the output?pin-configurationhttps://noctua.at/en/sip_productfaqnew/productfaq/view/id/215If you look at the pin-configuration theirs also a RPM speed signal pin. Does that pin have to be used?

author: madires
author_rank: Super Contributor
timestamp: May 18, 2019, 03:37:13 pm
content: You need only a 12V PSU. The MeanWell RS-15-12 should be fine. Yes, the PWM controller creates the 5V PWM signal for the fan (presumably it has a 5V regulator integrated). The RPM signal can be ignored.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 18, 2019, 06:40:17 pm
content: Quote from: madires on May 18, 2019, 03:37:13 pmOk, cool. Thanks alot for your help madires

author: james_s
author_rank: Super Contributor
timestamp: May 18, 2019, 07:00:31 pm
content: You could also use a salvaged "wall wart" type power supply. 12V is a common type, I find them at garage sales and junk stores, they are often orphaned from discarded electronic gear.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 18, 2019, 07:11:50 pm
content: Quote from: james_s on May 18, 2019, 07:00:31 pmIs this what your talking about? The fan is 550 ma so this one should be good right?https://www.kr4.us/wall-adapter-power-supply-12vdc-600ma.html?gclid=Cj0KCQjw2v7mBRC1ARIsAAiw34-zlz47No5jIRxcVnZyIbqTN0NRLgz8L71_moFedcgzU4d9Cxal6iUaAuyEEALw_wcB

author: james_s
author_rank: Super Contributor
timestamp: May 18, 2019, 07:18:53 pm
content: That ought to work. Do you not already have something like that laying around? I have a whole box full of random wall warts, but then I tend to always save that sort of thing whenever I discard broken or obsolete gear.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 18, 2019, 07:42:20 pm
content: Quote from: james_s on May 18, 2019, 07:18:53 pmNo I don't have one laying around. Im a "minimalist" if that's a word. I don't like clutter. I only keep what I use.hum... so let me ask you this... The mean well RS 15-12 looks like its capable of powering two fans but it only has one output. Could you have two sets of wires running off the + and two sets of wires running off the - of the power supply to power two NA-FC1's and fans?Thanks for your time james_s.

author: james_s
author_rank: Super Contributor
timestamp: May 18, 2019, 07:44:08 pm
content: Sure, you can parallel as much as you want from any power supply, so long as the total current drawn by the loads does not exceed what the power supply is rated to deliver.

author: Old Printer
author_rank: Frequent Contributor
timestamp: May 19, 2019, 04:30:01 am
content: Quote from: Food4MyBrain on May 18, 2019, 07:42:20 pmMinimalist Translates to "Makes a lot of trips to hardware store for every little project". My wife and I argue about it constantly. I buy a bunch of extra nuts and bolts and screws more than I need for a particular project. When it's done she wants me to return the leftovers, I want to keep them in my stash for that next inevitable project. So I don't waste two hours making a trip to Home Depot. I strip everything I can even remotely justify a future need or use. They call us scrounges , I take it as a compliment.

author: james_s
author_rank: Super Contributor
timestamp: May 19, 2019, 06:02:18 am
content: I probably tend to save too much stuff but it certainly comes in handy. Numerous times I've needed one thing or another and have found exactly what I needed in my stash and saved a lot of time which is one of the most valuable commodities there is. I really hate having to go to the store or place an order every time I want to build or fix something. I recently also got a significant sum of money for some NOS components that I had rescued from disposal years ago, I had no idea they were worth so much, I cringe at the thought of all the valuable parts other companies throw out just because someone sees them as clutter and doesn't recognize the value.Can't stand minimalism, a friend of mine is like that and his house feels completely sterile, it's like hanging out in a furniture store showroom or the waiting room at the doctor's office. Nothing to do, nothing interesting to look at or play with.

author: Brumby
author_rank: Unknown
timestamp: May 19, 2019, 06:02:53 am
content: Quote from: Old Printer on May 19, 2019, 04:30:01 amNot constantly, but my wife and I had this "conversation" at regular intervals. One day, however, the hinge on the freezer door broke and I was dutifully called in to fix it. Then three miraculous events occurred within the next half hour... #1. I looked at the broken hinge and recognised a piece of scrap metal I had might be just the thing. #2. I walked straight into the garage and grabbed the box which should have contained it - and it was there! #3. I had to make one bend (at exactly the right spot) for it to fit and work properly - and I did!The result was a repaired hinge in half an hour. From that day to this, I have never had that "conversation" again.

author: james_s
author_rank: Super Contributor
timestamp: May 19, 2019, 06:11:54 am
content: Quote from: Brumby on May 19, 2019, 06:02:53 amI had a very similar experience. She brought home the control pendant for the dental Xray machine at work, the exposure button had broken and they had a half dozen exams scheduled the next day that they would have to cancel and reschedule if the machine couldn't be fixed in time. I went out to the garage and dug through my boxes of scrap boards on the shelf and found an exact replacement for the tactile button in the pendant. Pulled it off that board, installed it and put it back together, saved the day. She never again has questioned the value of keeping boxes of scrap PCBs.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 19, 2019, 11:33:28 am
content: Quote from: james_s on May 19, 2019, 06:02:18 amTo each is own. Different life styles mate. My profession I'm always moving from job to job. It's a pain to carry a lot of stuff around with me hoping one day I'll use something. Just to kinda give you an Idea I'm working in the Bahamas on a small island 65 miles due East of Miami. There is nothing here. Anyway appreciate everybody's help.

author: Old Printer
author_rank: Frequent Contributor
timestamp: May 19, 2019, 02:33:25 pm
content: Quote from: Food4MyBrain on May 19, 2019, 11:33:28 am"Minimalist by necessity" gets a pass, kind of like pleading guilty with an explanation in traffic court.

author: Food4MyBrain
author_rank: Newbie
timestamp: May 19, 2019, 03:06:19 pm
content: Quote from: Old Printer on May 19, 2019, 02:33:25 pmBack to your cave troll