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General Category => Your projects => Topic started by: ketske on June 12, 2012, 23:06:01 PM

Title: Fan controller
Post by: ketske on June 12, 2012, 23:06:01 PM
Hello there!

My name is kenneth.
I am fascinated by electronics.
Im a beginner and i wanna learn more from you experts!

I have a project , my ps3 had ylod, i fluxed and flowed my console , succes.
Now i want to build a simple way like the rotary 4 way switch with resistors like the video.

Well my ps3 fan is 12vDC 1.76A= (6.78Ohms)
I wanna do it just like the one in the video .
Where do i start with the selection of resistors?

Last idea, can i make one with a potentiometer btw?

Your help is very appreciated!
Title: Re: Fan controller
Post by: kam on June 12, 2012, 23:07:29 PM
hello kenneth,
for which video with rotary encoder you speak about?
Title: Re: Fan controller
Post by: ketske on June 12, 2012, 23:09:51 PM
Wow that was fast attention , thank you! ( poor english =_=)
well this:  http://www.youtube.com/watch?v=fRWn9uwPiUY&feature=related
Title: Re: Fan controller
Post by: kam on June 12, 2012, 23:16:45 PM
Ok i see. Question: are you absolutely sure about the 1.76A? Do you mean 1.76 Watts? Because 1.76A at 12V means 21 watts fan...is it really THAT powerful?

Well, the bad news are that if your fan is 20 watts, you cannot simply dissipate power on some resistors. The power is too high. The good news are that you can always use a very simply PWM controller with a 555 timer and a few simple components. In that case, you will have a potentiometer. Here is one circuit:

http://www.pcbheaven.com/circuitpages/High_Frequency_PWM_Fan_Controller/
Title: Re: Fan controller
Post by: ketske on June 12, 2012, 23:23:13 PM
Yes , take a look at this :-)
http://www.youtube.com/watch?v=EYN9kc1R-94
skip to 1:36

Oh alright
Thanks for the information

if i have questions i will get back to you , thank you very much!
Title: Re: Fan controller
Post by: ketske on June 12, 2012, 23:24:41 PM
but what resistors and etc do i need actually? for to run this 21watts?
Title: Re: Fan controller
Post by: kam on June 13, 2012, 08:26:40 AM
You will follow the schematic "What about the 3-wire and the 2-wire fans?". The material list is underneath.
Title: Re: Fan controller
Post by: ketske on June 13, 2012, 17:39:51 PM
Is this material list compatible with the 1.76A(21w) fan ?
Or is there a limit on this ?
So yes how can i calculate this?

thank!s
Title: Re: Fan controller
Post by: kam on June 13, 2012, 20:48:26 PM
Q1 is IRF520 which can stand 9Amps.. so you wont have a problem
Title: Re: Fan controller
Post by: ketske on June 15, 2012, 20:18:02 PM
After some search work, i can buy a timer and diodes
but i cant find thos annywhere .


R1   Resistor 1 KOhm 1/4 Watt 5% Carbon Film   
R2   1 KOhm potentiometer
R3   Resistor 4.7 KOhm 1/4 Watt 5% Carbon Film   
Capacitors
C1   0.1 uF ceramic capacitor  <- and is this 16 volts ?
C2   1 uF 16 Volts electrolytic capacitor

Someone else can find them?

Dutch(holland) site's are  aprecciated

thank you!
Title: Re: Fan controller
Post by: kam on June 17, 2012, 17:27:22 PM
www.futurlec.com
Title: Re: Fan controller
Post by: ketske on June 17, 2012, 22:54:40 PM
Thanks alot kam!
Title: Re: Fan controller
Post by: kam on June 17, 2012, 23:46:09 PM
you're welcome! 8)
Title: Re: Fan controller
Post by: ketske on June 20, 2012, 20:02:56 PM
ok ive got al components and soldered in place , now i can't read it so good the 3 wire draw.
can someone help me out?

which pin of the timer is  for sample: RST?

can someone explain it a little bit simpler?

thanks!

and what are the zero volts connections about?
Title: Re: Fan controller
Post by: kam on June 20, 2012, 20:24:34 PM
Sampling? What sampling? The 555 timer does not get sampling from the fan
Title: Re: Fan controller
Post by: ketske on June 20, 2012, 20:51:07 PM
http://imageshack.us/photo/my-images/840/highfrequencypwmfancont.png/ (http://imageshack.us/photo/my-images/840/highfrequencypwmfancont.png/)

now, all my solderings are done, ive got it but.. .
Where does the 12v arrows to? just to the supply? and also the zero volts signs?
where do i connect it ?
Title: Re: Fan controller
Post by: kam on June 21, 2012, 08:10:19 AM
the 12v with the arrows pointing up, goes to the supply 12V. The 0V goes to the supply 0V. The connector on the top-right goes to the fan - 12V and 0V. The 3rd wire (yellow-tach) is not used.
Title: Re: Fan controller
Post by: ketske on June 21, 2012, 19:29:47 PM
Alright i soldered eveything together , but no luck with starting it , the fan wont turn .
Can it be a bad resistor?

I measured the 1 kohms resistors and 1 of them only measures 0.521 kohms and the other 1.005 kohms.
Could that be the fault?

thanks !
Title: Re: Fan controller
Post by: kam on June 23, 2012, 14:25:39 PM
most common mistake that people make with this circuit is the diodes, they connect them wrong. Verify twice that you've soldered them correctly.
A bad resistor in terms of 50% error would not cause the circuit to stop, only to malfunction. So this is not the problem. Make also sure that the mosfet is not dead already. Beware with mosfets, they are sensitive to heat during soldering and to static electricity from your body.
Title: Re: Fan controller
Post by: ketske on June 23, 2012, 18:33:20 PM
most common mistake that people make with this circuit is the diodes, they connect them wrong. Verify twice that you've soldered them correctly.
A bad resistor in terms of 50% error would not cause the circuit to stop, only to malfunction. So this is not the problem. Make also sure that the mosfet is not dead already. Beware with mosfets, they are sensitive to heat during soldering and to static electricity from your body.

IT WORKS!

Thanks kam , you are a HERO! Like a boss !

btw one thing, when i turn the pot it gives an anoyying sharp tweety sound, i tought this diagram would prevent this or am i wrong?

* they didn't had anny mosfet irf520, so they gave me a 530*

the fan has brown grey and black, so i put the grey (tach) on the brown 12v line and that worked, i gonna test it with only the grey, because with the brown it will start but not turn .

with grey it won't turn

i was thinking, would i add an other electrolytic capacitor?
Title: Re: Fan controller
Post by: kam on June 23, 2012, 19:33:25 PM
Yes you are right, it should not make any noise. This means that either you have ultra-sonic hearing capabilities like superman, or the 555 oscillates bellow 18KHz. I put my money on the second...
To increase the frequency, either use a smaller potentiometer or a smaller capacitor for C1. Tell me the values you use for R2-R3-R4 and C1
Title: Re: Fan controller
Post by: ketske on June 23, 2012, 19:54:08 PM
Yes you are right, it should not make any noise. This means that either you have ultra-sonic hearing capabilities like superman, or the 555 oscillates bellow 18KHz. I put my money on the second...
To increase the frequency, either use a smaller potentiometer or a smaller capacitor for C1. Tell me the values you use for R2-R3-R4 and C1
C1   0.1 uF ceramic capacitor
R2   1 KOhm potentiometer
R3   Resistor 1 KOhm 1/4 Watt 5% Carbon Film   
R4   Resistor 330 Ohm 1/4 Watt 5% Carbon Film

so you wanna say that i may need to ad another capacitor beside the one i already have  or pot on the circuit?

*maybe this help to think what it should be , when i turn te pot to full resistance the fan goes off*
Title: Re: Fan controller
Post by: kam on June 23, 2012, 20:50:02 PM
ok, you can increase the frequency by replacing the cap with a smaller one. A 47nF would do the job.
Title: Re: Fan controller
Post by: ketske on June 23, 2012, 22:53:52 PM
ok, you can increase the frequency by replacing the cap with a smaller one. A 47nF would do the job.

ok, and i think this circuit increases the fan until 45 %?

how can i increase the speed? until lets say : 75?

Or am i wrong?
Because the fan at full turn of the pot , isn't working at i guess not more than 60%?

because of the watts? then this means i need to add as wel an ceramic for the cycle to get running in low neutral cooling and an electrolytic(higher in place?) to get higher speed?


am i right?

my pwm construction
http://www.youtube.com/watch?v=c80YRj3_-Iw&feature=youtu.be
Title: Re: Fan controller
Post by: kam on June 24, 2012, 11:04:53 AM
If the fan does not go to full speed, then there is something going wrong with R4. Is it connected to the right position? This resistor is used to set the minimum speed. Try this: bridge the resistor R4 with crocodile clips and try again. If the speed goes up to 100%, then the resistor is connected on the wrong side.
Title: Re: Fan controller
Post by: ketske on June 24, 2012, 12:46:34 PM
If the fan does not go to full speed, then there is something going wrong with R4. Is it connected to the right position? This resistor is used to set the minimum speed. Try this: bridge the resistor R4 with crocodile clips and try again. If the speed goes up to 100%, then the resistor is connected on the wrong side.
I switched the connections on the r4 and i bridged it , but no succes actually, when i turn the pot to 1/4 less resistance (to almost ful turn of 3/4th) the fan goes off
it goes back on to the 60% about half the way .
so i think its maybe the r4 itself?
or maybe somewhere wrong connected.
i think its the 555 or the electrolytic cap.
Title: Re: Fan controller
Post by: kam on June 24, 2012, 13:04:00 PM
The electrolytic cap C2 is only to smooth the voltage and absorb any ripples. It has nothing to do with the operation of the fan. 
To ensure that 555 operates correct, remove R3 completely, and replace R4 with a wire...
Title: Re: Fan controller
Post by: ketske on June 24, 2012, 13:55:54 PM
The electrolytic cap C2 is only to smooth the voltage and absorb any ripples. It has nothing to do with the operation of the fan. 
To ensure that 555 operates correct, remove R3 completely, and replace R4 with a wire...
this will smoothly set the fan to 100%? or the mossfet because a high input impedance is needed?
correct me if im wrong.
but i gonna test your suggest soon.

thanks!
Title: Re: Fan controller
Post by: kam on June 24, 2012, 14:42:54 PM
It will smooth the input voltage. By the way, how do you power the circuit??
Title: Re: Fan controller
Post by: ketske on June 24, 2012, 20:10:34 PM
It will smooth the input voltage. By the way, how do you power the circuit??
12v connected on the psu from the PS3 with the zero line to the fan molex to where it used to sit so ..
btw tomorrow i gonna check the circuit again on maybe a fault connected part .

thanks!
Title: Re: Fan controller
Post by: kam on June 25, 2012, 11:56:04 AM
if the supply has ripples due to the switching of the mosfet, then yes, you will be needing a larger capacitor indeed.
Title: Re: Fan controller
Post by: ketske on June 25, 2012, 12:19:43 PM
if the supply has ripples due to the switching of the mosfet, then yes, you will be needing a larger capacitor indeed.
Allright, and a ceramic capacitor?
So an higher 47nF ceramic and  how can i calculate this to get the correct electrolytic cap ?


Title: Re: Fan controller
Post by: kam on June 25, 2012, 16:02:56 PM
for the electrolytic, in case that you have ripples, it is ok to use one 1uF and one 1000uF... Typical values.
Title: Re: Fan controller
Post by: ketske on June 25, 2012, 17:11:30 PM
for the electrolytic, in case that you have ripples, it is ok to use one 1uF and one 1000uF... Typical values.

i think this is running good but only i cnat get the full speed and what you said the ripples.
so with these2 changed it would be fine?

besides the ps3 pwm fan
if a attach this to a 0.16a 12v fan it will start but  wont turn , i think this happens because this circuit has too much resistance?
Title: Re: Fan controller
Post by: kam on June 25, 2012, 20:10:50 PM
hmmmm why don't you post some photos to have a look?

The circuit has minimum resistance. This mosfet has much less than 1 ohm turn-on resistance.
Title: Re: Fan controller
Post by: kam on June 25, 2012, 22:42:25 PM
from what i can see, both diodes point to the same direction. If this is true, then this is the problem. Doublecheck the diodes, this is the most common mistake that people do with this circuit.
The mosfet is very had to kill unless you wire it wrong.

I suggest you (always) prototype your circuits on breadboard, this way you cave the chance to 1. select the final part values and 2. get to see if the circuit fits your needs

It is impossible to see what is wrong with these pictures...  Get a breadboard and try this again. It will eventually work.
Title: Re: Fan controller
Post by: ketske on June 26, 2012, 12:40:15 PM
allright ive got it work now , but i think a wire get off and the mossfet's drain or gate gets a lil spark.
so i tested the mossfet with gate and source on the ground and 12 on the drain , when it lets 12v trough the gate or source, its broken , right?
so i mount it back and i cant get control it just spins 100%
and i tested the 555 like u said and the fan spins smooth to 100%
Title: Re: Fan controller
Post by: kam on June 26, 2012, 15:20:17 PM
the mosfet probably has waved bye bye.... What was the problem? the diodes?
Title: Re: Fan controller
Post by: ketske on June 26, 2012, 15:35:56 PM
the mosfet probably has waved bye bye.... What was the problem? the diodes?
mmm no a lil wire loosed i guess , lill crappy tho, but now ive done a lill homework and i did this succesfully
next im gonna do some more serach work to bring a simple a pot on it so , like this diagram on pcb.

with this im happy for now ..

Kam i very appreciated your attention, i hope i am wasn't too anoyying to you :-p!
And until next time!

keep up the good work! :-)

kenneth
Title: Re: Fan controller
Post by: kam on June 27, 2012, 18:18:37 PM
looking forward to see your next project mate ;)