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Author Topic: Fan controller  (Read 8983 times)

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ketske

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Re: Fan controller
« Reply #15 on: June 20, 2012, 20:51:07 PM »
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 ?
« Last Edit: June 20, 2012, 22:36:30 PM by ketske »

kam

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Re: Fan controller
« Reply #16 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.

ketske

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Re: Fan controller
« Reply #17 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 !
« Last Edit: June 21, 2012, 23:12:54 PM by ketske »

kam

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Re: Fan controller
« Reply #18 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.

ketske

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Re: Fan controller
« Reply #19 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?
« Last Edit: June 23, 2012, 18:52:37 PM by ketske »

kam

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Re: Fan controller
« Reply #20 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

ketske

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Re: Fan controller
« Reply #21 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*
« Last Edit: June 23, 2012, 19:58:25 PM by ketske »

kam

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Re: Fan controller
« Reply #22 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.

ketske

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Re: Fan controller
« Reply #23 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
« Last Edit: June 24, 2012, 11:17:39 AM by ketske »

kam

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Re: Fan controller
« Reply #24 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.

ketske

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Re: Fan controller
« Reply #25 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.

kam

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Re: Fan controller
« Reply #26 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...

ketske

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Re: Fan controller
« Reply #27 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!

kam

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Re: Fan controller
« Reply #28 on: June 24, 2012, 14:42:54 PM »
It will smooth the input voltage. By the way, how do you power the circuit??

ketske

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Re: Fan controller
« Reply #29 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!