I NEED HELP 5V TO 10V PWM
- Thread starter Growmau5
- Start date
xX_BHMC_Xx
Well-Known Member
On a somewhat related topic, I was just looking at the tech sheet for the Arctic F8/F12 and it shows fan speed of about 450rpm at 0% pwm with 12v power. With 5v or 7v power, the graph shows 0rpm up to 10%pwm, then the fan kicks on. Does this mean the fan is never actually off with 12v power?
Yesdog
Well-Known Member
https://www.rollitup.org/t/diy-steady-state-cxb3590-build-w-raspberry-pi.934250/
Bunch of pics and some other tech details. But damn, it definitely works!
Yeah, at least the CPU fans I've seen never go completely off. I feel like its an extra safety feature so you dont fry your CPU. It's pretty nice here too, I know I can never totally turn off the fans. Plus the control lead on the 4-pin fans, if it ever goes floating (like most GPIO pins on the rpi seem to do after reboot), the fans go to 100%. So on power-un, during Linux boot and stuff (for me), it defaults to 100%. sounds like a desktop starting up lol
Bunch of pics and some other tech details. But damn, it definitely works!
Yeah, at least the CPU fans I've seen never go completely off. I feel like its an extra safety feature so you dont fry your CPU. It's pretty nice here too, I know I can never totally turn off the fans. Plus the control lead on the 4-pin fans, if it ever goes floating (like most GPIO pins on the rpi seem to do after reboot), the fans go to 100%. So on power-un, during Linux boot and stuff (for me), it defaults to 100%. sounds like a desktop starting up lol
Yesdog
Well-Known Member
so, one thing I just added here was a 100k potentiometer as the resistor that goes across (parallel) the DIM leads. I've tested it all finally, and combining PWM and resistance based dimming definitely works together as you would expect. I measured the wall wattage, and its mostly linear as expected (except below 50% and efficiency drops per the data sheet). So I can use the pot to set the max amount of dimming, at like... 8V (80kOhm, 80%) and drive the PWM to ground like normal, and at 50% PWM duty cycle, I'll get the expected 40%. I've got the one amp driver, seems it can push these things to some intense thermals- so its nice to have a physical limit incase my software goes crazy
EDIT: heh, software has been working good far. If i have the thermals set to like 30*C, and I manually crank the potentiometer up, software ends up taking it back down to about where it was before.
EDIT: heh, software has been working good far. If i have the thermals set to like 30*C, and I manually crank the potentiometer up, software ends up taking it back down to about where it was before.
xX_BHMC_Xx
Well-Known Member
That's a nice safety feature for sure. I was planning on running the StormX as a result of not knowing much about Arduino/Rpi, but the more I think about it, the more I want to go that route. Got any good resources I should check out?
Yesdog
Well-Known Member
The RPi was a good choice for me because I knew I wanted to run linux. But if you're not picky about that stuff, the arduino is definitely the way to go. They're both very capable machines for sure. But it's definitely a small linux computer- it's kind of a big jump in complexity
As far as resources, the information for both devices scatters pretty far in all directions. Really easy to google stuff.
The arduino, for the most part you have to use their language or I think... pure c? cant remember. But you don't have to deal with linux.
The rpi gives you access to a bunch of different languages, the WiringPI library is probably the #1 interface library for doing things on the pins, also available in a bunch of languages.
There's countless libraries and things for arduino too, both have tons of support on the web.
VegasWinner
Well-Known Member
try s TIP 120 MOSFET transistor
There are options to usi9ng a stormx controller for aquariums. You can build your own six channel controller or buy a six or eight channel controller from GrowGreen for less than stormx and works better too. stormx has one on/off schedule for all channels GrowGreen has six or eight on/off schedules with pwm dimming as well similar to stormx but better. GrowGreen uses both pwm dimming and on/off for each signal. just googler GrowGreen Led controller or PM me. I have been working on both arduino and RPI solutions.
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