Hey Guys, this is a awesome thread, I'm thinking of building NE556 based controller, the thing is my System has a bunch of 3 wire Fans also, I just need to know if I can Drive a FET using the PWM signal and control a 3 wire fan, AFAIK PWM fans has a FET internally to do the same thing right? any help would be much appreciated.
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FEATURED Building PWM Controller for 4 wires PWM fan
- Thread starter Brutal-Force
- Start date
- Joined
- Oct 17, 2011
- Location
- Orange County, CA
The PWM pin is an input to the motor driver IC. In a primitive implementation it might just be AND-ed into the bridge driver logic but given that most fans spin at 20% when the PWM signal is low it's more complicated than that.
Tip31c will do just fine, search my name. I made a easy thread on it
Hey Thanks so much Amora, So it happens to be I have some TIP31C's in my junk box, will read your thread too
Hey Thanks so much Amora, So it happens to be I have some TIP31C's in my junk box, will read your thread too
Just a warning, make your 555 circuit frequency modulating friendly. Some fans make wining and/or growling noises if you choose the wrong frequency. In my experience the pwm freq that comes off my mobo seems to satisfy most fans I've tried.
Also be weary of the amperage your trying to pull through a single transistor, they get pretty hot when the amps are +1.3a
OK so should I make the Dual 555 based one or the Single 555 based controller ?, I was thinking of Building this
It's the same thing on this thread I think, As for the heating issues, I might use a Small heatsink on the Transistor, also the fans I'm controlling don't suck up a lot of Amps (Stock fans of a Corsair H80, I hate it's three step fan controller and the fans are non PWM :/) the rest of the fans are Scythe Slipstream PWM's
Use the dual stand alone 555 w/ comparator circuit. I allows for a fixed frequency when compared to the 556. Who's frequency and duty cycle are latched. Ie when I changed the potentiometer both the freq and duty cycle change. Alough I have this 556 driving my mcp35x, when used to pwm fans, it create growling whining off all sorts from the motor.
- Joined
- Apr 4, 2011
i believe it's on the few first page (sorry I've lost my bookmark, and I've already downloaded the schematic
), just look for the 2x NE555 + LM311 schematichello,
I'm tryin' to share you the noise problem the I've got with the Sanyo SG.
the vid was made by a friend o' mine, but the noise profile are very similar with mine.
here's for the 2-98% version:
and here's with the 0-100% version (using NE556 + LM311, instead of 2x NE555... and an additional Inverted Schmitt Trigger to set the output to the non inverted signal)
@nothor
were these noise profile are similar with yours, especially on the 0-100% version?
@bing
did you use the 16kHz frequency as suggested by Sanyo Datasheet on the kickstart video?
your fan was incredibly silent on the vid
on the vid, I can only see 3 IC on your bread board, is there anyhow to set the output of the 0-100% with the kickstart circuit to outputing the non inverted signal,
since mine the kickstart circuit only work with the inverted output (without extra IST)
- Joined
- Aug 10, 2010
- Location
- Sunshine State
i believe it's on the few first page (sorry I've lost my bookmark, and I've already downloaded the schematic
It's on page 2 of the thread. Post 25 to be more exact.
Here
Thanks guys, I'd been scanning through quickly looking for images, missed the links. I know it's utterly unrelated to the thread topic, but I've discovered an SMD LED car foglamp (120 LEDs, costs ~$AUS5) that run at 2.5W(!) on 12V is more than bright enough to use as a desklamp, so needs a little dimming (nice power saving too).
FWIW this's a version of the same kind of thing, using a 556 instead, and driving a FET for arbitrary loads. An IRF531 is good for 20A.
FWIW this's a version of the same kind of thing, using a 556 instead, and driving a FET for arbitrary loads. An IRF531 is good for 20A.
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@bing
did you use the 16kHz frequency as suggested by Sanyo Datasheet on the kickstart video?
your fan was incredibly silent on the vid
on the vid, I can only see 3 IC on your bread board, is there anyhow to set the output of the 0-100% with the kickstart circuit to outputing the non inverted signal,
since mine the kickstart circuit only work with the inverted output (without extra IST)
Yes, in that video, the freq was 16 Khz, yeah, noise is quite nice at low speed.
The board I used was the 0-100% version with 3 ICs, yeah, its not that clear in the video.
Actually I was planning to use the nicely buillt gift that one that you sent me, but it was "robbed" by my friend when visiting my place.
- Joined
- Apr 4, 2011
Yes, in that video, the freq was 16 Khz, yeah, noise is quite nice at low speed.
The board I used was the 0-100% version with 3 ICs, yeah, its not that clear in the video.
Actually I was planning to use the nicely buillt gift that one that you sent me, but it was "robbed" by my friend when visiting my place.
thanks for clarifying this
sorry to hear bout the incident
but, the one that I sent you was the 2-98% version, and it's really making that annoying noise from the SG at low speed, even when the frequency was set @16kHz
let's build something better for our precious SG then
- Joined
- Jul 4, 2012
Yes, in that video, the freq was 16 Khz, yeah, noise is quite nice at low speed.
The board I used was the 0-100% version with 3 ICs, yeah, its not that clear in the video.
Actually I was planning to use the nicely buillt gift that one that you sent me, but it was "robbed" by my friend when visiting my place.
Do you happen to have a drawing of that setup available? Currently I have the dual 555 circuit setup with reverse Schmidt buffer (from here) on my breadboard and my 260 cfm San ace 12v 4a is of its way in the mail. I'm curious as to what I have to change to be able to run from 0-100 at 16khz as you are doing.
Thanks so much for the information!
- Joined
- Jul 4, 2012
I appreciate the input, but if the sensor circuit in the fan is tuned for 16000 pulses per second, then sending a signal over that will still appear to work correctly to the human eye. The dilemma begins to arise in that the a 25000 pulse per second signal being perceived at 16000 pulses per second will create an unnoticeable irregularity in the on and off switching that may or may not introduce excessive wear on the motor. Perhaps I'm wrong, but I'm neurotic enough to want to get it perfect.
