psu for gadgets

[amandpm]

Any one know what people use to power up 12v dc fans for testing?
fans are 36w 12vdc (2.6a?) Digital would be nice. trying to figure out how to use these fans for the pc but want to be able to control the rpms but can't find anything like that above 20w max (fan controller).

[jonnyGURU]

How many of these 36W fans do you plan to use?

Are you using them in a PC? Sounds loud. :D

[amandpm]

How many of these 36W fans do you plan to use?

Are you using them in a PC? Sounds loud. :D

Not sure how many to use in each pc it kind of depends on if i can control the fans or if i got to run them full speed. I have like 30 of these fans and I am pretty sure there for a HP server used for the fan exhaust.
Loud ...well i just jury riged one to a DC power supply made bye micronta, set it at 12v touched the wires to the fan and it ran and was quiet but i am sure it was not getting 3amps or 36w from the Micronta (no specs its old) well I have other fans Delta, San ace but i wanted to give these a shot.
I am just wondering if a person could somehow tie together 2 lines from the sunbeam fan controller? each line handles 20w not sure about amps. Is there a way to run one fan from 2 lines off the Sunbeam controller?
Thanks

[jcgamo88]

http://www.ocforums.com/forumdisplay.php?f=128

You'll find some fan mods there at the top including a homemade fan controller.

As for hooking two fans into one line, I'm fairly certain you'd have a lose in total energy reaching each. But then again I failed Physics for not paying attention.

[amandpm]

http://www.ocforums.com/forumdisplay.php?f=128

You'll find some fan mods there at the top including a homemade fan controller.

As for hooking two fans into one line, I'm fairly certain you'd have a lose in total energy reaching each. But then again I failed Physics for not paying attention.
Thanks for the link:)
I just want to hook One fan up into 2 lines from a 4 line fan controller, the fan uses almost 3a and 36w 12dcv I was hoping some how it could be done.

[LC_STiK]

Just hook the positives on top of each other to increase amps, link positive to negative (in the correct order) to up the voltage. 0-24v adjustable fans anybody?

Otherwise, you can buy 50w rheostats at a couple of online stores.

Check sidewinder.com, xoxide, frozencpu and bestbyte for stuff.

They're only $5 apiece.

[amandpm]

Just hook the positives on top of each other to increase amps, link positive to negative (in the correct order) to up the voltage. 0-24v adjustable fans anybody?

Otherwise, you can buy 50w rheostats at a couple of online stores.

Check sidewinder.com, xoxide, frozencpu and bestbyte for stuff.

They're only $5 apiece.

Thanks for the advice I was looking at Rheostats last night on the web but not knowing much about eletricity i didn't know what ohms to get.

[LC_STiK]

I don't know that much about electricity, but isn't adjusting ohms what lets the rheostat adjust voltage. More resistance=less voltage, so when you turn the knob, that's what's really going on right?

[CBRworm]

I have a matrix orbital display/fan controller, but my experience with fans like what you are describing is that they are loud with PWM controllers - so you may be better off with a rheostat of some sort. I don't know where you would find one that wouldn't burn up with that kind of power though.

You might be better off to buy some regular computer fans and keep those for your car amp compartment or something.

As for testing outside of the computer, there are a lot of commercially available 12 volt power supplies with variable output. I have a fixed output 50 amp, and somwhat variable 35 amp that will go down to 10 and up to 15.

The best for what you are describing is a bench top power supply - they typically are adjustable from 0-30 volts with very small increments. I have one that will put out 5 amps. It would be perfect for you. I bought mine from a company locally here called Marlin P Jones, but you could look at their site and get some ideas.

http://www.mpja.com/products.asp?dept=2

[amandpm]

As for testing outside of the computer, there are a lot of commercially available 12 volt power supplies with variable output. I have a fixed output 50 amp, and somwhat variable 35 amp that will go down to 10 and up to 15.

The best for what you are describing is a bench top power supply - they typically are adjustable from 0-30 volts with very small increments. I have one that will put out 5 amps. It would be perfect for you. I bought mine from a company locally here called Marlin P Jones, but you could look at their site and get some ideas.

I just bought a used BK Precision model 1670 digital dc power supply..........One variable 0-30 VDC, 2.5 A section
One 12 VDC fixed section
One 5 VDC fixed section

Specifications


Output Voltage Main 0-30 VDC
Fixed 12VDC +- 5%
Fixed 5 VDC +-5%
Output Current Variable 0-2.5 A
Main Fixed 0-500 mA continuous
Fixed 0-500 mA continuous
Constant Voltage Operation
Voltage Regulation
Line (120 VAC +- 10%) <= 0.05% + 10 mV Main
<= 1% (A&B)
Load (0 to rated load) <= 0.05% + 10 mV
<= 1% (A&B)
Recovery Time 100us
Ripple & Noise <= 1mVrms
Temperature Coefficient <= 300 ppm 0 C
Constant Current Operation
Adjustable Current Range 5% to 100% (Main)
Current Regulation
Line (120 VAC +- 10%) <= 0.4% + 10mA
Load <= 0.4% + 10mA
Current Ripple <= 10 mA rms
Metering
Display 2 digital LCD
Voltmeter Range 0 to 12 VDC 0 to 5 VDC
Voltmeter Accuracy +- (0.5% reading + 1 digit)
Ammeter Range 0 - 2.5 A
Ammeter Accuracy +- (0.5% reading + 1 digit)
Overload Protection Current limiting, Reverse polarity, overvoltage, Short circuit
Power Requirements 108 - 132 VAC 60 Hz, 120/220/230/240/VAC, +- 10%, 50/60 Hz version available
Power Consumption 170W
Operating Temperature 0 0 to 40 0 <=75% R.H
Storage Temperature -15 0 to 70 0 C <= 85% R.H
Dimensions (HxWxD) 5.5x5.9x24'' (140x150x240 mm)
Weight 10 lbs. (4.5 kg)

For testing fans everything works good on the 12v & 5v line but i think somthing is wrong with the adjustable 0-30v 0-2.5a line OR i just don't understand how to use it right. I have two knobs one for Voltage and the other one for Current when i plug the unit in with no load anywhere on any line the digital display ready 47.7Volts and the Amp display reads 0.01 and 0.02 back and forth, now thats with both knobs midway between low and high.
Below those knobs is a "Current limited" light now it don't turn on untill the Current dial is turned counter clockwise towards Low, just almost all the way low then the Current limited light will go on, and right at that moment the Voltage drops from 47.7V to 1.2V and the Amp display goes to-0.00, Now at this point turning the Voltage knob does nothing...long story short i have a box of 80mm fans I hooked one up to the adjustable it Fried with in seconds...
At this moment i am getting another fan to try it with the Current limited light on...ok i think i got part of this power supply figured out...as long as the current limited light is on i can control the voltage & amps ..I just ran the 80mm fan up to 12.2V and 0.23A DUAAA Me lol
As soon as you turn the Current knob (which is very little) clockwise and the Current limited light goes off then at that moment the fan Fries...Problem is i have never used a "bench" power supply and I don't have a manual so i got to wing it on my own.

[CBRworm]

It sounds like maybe the supply you got is defective, the specs look like it should do what you want.

You shouldn't be getting 47 volts output no matter what the settings are.

The current limiter is working, but that is not how you should have to adjust voltage. I would usually leave the current limit knob set at the max unless yI am testing something I'm afraid might cook itself. In your case it sound like the current limiter is the only thing doing any regulation. Normally with the current limit set at the max, before you connect the fan you should be able to adjust the voltage down to 12 or so volts using the voltage adjust knob.