PDA

View Full Version : Looking Motor driver with PWM



TC
07-17-2006, 08:07 AM
This might sound a little dumb but I need to find A motor driver for 10 ( yes ten ) 80mm cooling fans .37A each. that has PWM control. all 10 fans are hooked together. I am looking for at least 4 step control ( 0%, 25%, 75%, and full speed) it must hook up to a BS2p, and handle 12V

thanks
TC

Bruce Bates
07-17-2006, 09:29 AM
TC -

You neglected to mention whether it's AC or DC? If it's DC the Parallax HB-25 should be able to handle that with it's eyes closed http://forums.parallax.com/images/smilies/smile.gif

The Parallax Part Number for the HB-25 is 29144, and additional information can be found on their web site..

Regards,

Bruce Bates

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
<!--StartFragment -->

Lightfoot
07-17-2006, 10:06 AM
80mm PC case fans? Have a microcontroller generate pulses and a power transistor amplify them for the fans. Don't forget a flyback diode.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Well well, I'm seeing things, three of them.

-Stanley Blystone

TC
07-17-2006, 11:10 AM
Bruse,··· Sorry, They are DC brushless computer case fans. I was/am thinking about the Parallax driver. still weighing my pros and cons. One thing I cant do is keep telling the controler what speed to be at. I need just like that infomercial selling that RONCO product " SET IT AND FORGETIT". The program I am working on has other things to do.

Moe,····· I am not that grate with electronics. and as I explaned to Bruse I cant aford to waste the BS2p's time controling the fans.

thanks for the replys
TC

Bruce Bates
07-17-2006, 11:34 AM
TC-

That still doesn't disqualify the HB-25, but you may not need anything quite that sophisticated.

Regards,

Bruce Bates

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
<!--StartFragment -->

bennettdan
07-17-2006, 09:48 PM
Do need the fans to be controlled by a temp sensor of any kind or just come on at different times?

TC
07-17-2006, 11:35 PM
The fans need to be controled by the BS2p. I am reading the temp, then the stamp decides if it need to turn on the fans and at what speed. I could just use a fan controler. but the stamp is going to display the temp on a VFD display as well as primary battery voltage, secondary battery voltage, secondary charge current, amplifier temp (*2), isolator on/off, system on/off, fan speed %, and more to come. I still have been looking to find a motor controler that goes one way and that has PWM control. I could just turn the fans on or off but the fans are loud (4500 RPM each). And if I am just showing the system at low volume I dont need full speed.

Thanks

TC

bennettdan
07-18-2006, 08:56 PM
TC,
I think I have a good curcuit for you it is easy to build and cost very little. When I get home tonight I will post it on here for you. Also it will tie up the processor and has 0-100% control with 128 steps. To free up a pin for use on your fans you can take the wire from pin15 and run it directly to pin 1 on the 74HC132. Thi curcuit only uses 3 components minus the stamp and just use a mosfet big enough to handle your load.

Post Edited (bennettdan) : 7/28/2006 1:17:35 AM GMT

TC
07-20-2006, 07:04 AM
bennettdan,

Thank you for the reply. I will try that out and I will let you know how it went

bennettdan
07-21-2006, 09:44 AM
TC,
Are you building a battery charger?

TC
07-22-2006, 06:24 AM
bennettdan,

No it is to cool my amplifiers. I am working on a little project that will monitor & control·my hole audio system and display it on Parallax's VFD display in my dash board, and the stamp is going·to control it all.

TC

bennettdan
07-22-2006, 09:38 AM
Cool,
To sense your temp use a thermistor they interface with the stamp with just the RCTIME comand.

TC
07-23-2006, 09:06 AM
I am going to use two LM34's I have 5 ADC0831's (freebie), So goto use them

TC

bennettdan
07-26-2006, 01:37 AM
TC
How is the PWM curcuit going?

TC
07-26-2006, 08:19 AM
Bennettdan,

Well I could not find a cheep motor driver. So I am going to try and build my own using a LMC555, a MOSFET, a shift-register. I have not worked with electronics for about 10 years and I hope I will be able to figure it out. And if I get it worked out I will place what I found here. Or I might use a BS1. I dont know what I am doing yet. But I would like to thank everyone who tryed to help.

TC

bennettdan
07-27-2006, 03:24 AM
The curcuit I gave you is very easy to build and gives you 0-100% control with 128 steps

TC
07-27-2006, 07:12 AM
Bennettdan

I think I would be better off using your curcuit. I am just blowing up parts (been aloooong time). but I do have a few questions if you could help

1) What value did you use for the AD5220 ?

2) Would R8 & R9 change if I change the IGBT to a IRF510 MOSFET (Have one laying around)?

3) should there be a restior between the 74HC132 & 4N25?

Thank you for all of your input and help

TC

bennettdan
07-27-2006, 07:37 PM
Hey TC,
Sorry about that it is an old diagram...
1)The AD5220 is a 10K same as the one in the WAM parts kit..I but mine from Digi-Key.

2)The value for R8 and R9 should work fine for you R9 can be less if the 4n25 starts to heat up, R9 makes the mosfet or IGBT turn off faster you can use a 10k for R9 if you wish.·Also if you plan to use a mosfet instead of a IGBT change the 15v going to the 4N25 to 12V.

3)Yes their should be a resistor between the 74HC132 and the 4N25 I use a 470ohm.

Sorry about the mistakes I will modify the schematic and repost it on the original (man that was a terriable schematic).

ALSO for the C2 try using a .1 instead of the .01 this will lower your frquency and shoul work better for your fan.
D1 needs to be able to handle your current so find a 10 amp if you use the If510

the D3 and D4 can be a 914 diode if you have them ....
you wont need the stiffening caps I dont believe...and dont use 144vdc to power the fans..LOL...lower it to 12v

The entire setup should only cost a few dollars to build and heasink the mosfet...and put it behind on of your fans to keep it cool if you have room..Good Luck.

I have some code to get you started when you get it built..hit me back

Post Edited (bennettdan) : 7/27/2006 11:45:01 AM GMT

bennettdan
07-28-2006, 09:18 AM
Hey I put the updated diagram on the original post .