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Variable Voltage for logs using a PC fan controller - A work in progress

Discussion in 'Vapor Related Equipment' started by z9, Feb 19, 2014.

  1. z9

    z9 Well-Known Member

    Messages:
    712
    I've wanted to power a 12V log through my PC for a long time; I don't currently have a variable voltage power supply so I finally had the motivation to look into using my desktop for power.

    Powering my log from my desktop is convenient for me seeing as my computer desk doubles as my vape station and is always on during the day. I can't leave my log at 12 volts all day and I'm too impatient to wait for it to heat up. Why not just buy a real vvps you might ask... because that would be too easy.

    I used an old fan and old fan speed controller. I cut off the 3 pin connector from the fan and I cut the tattoo connector (for lack of a better term) off of the power cord and used a wire nuts to connect the cables, I then hooked everything up and powered on my PC. Instant variable voltage... the vape performs just like it should at 12 volts. I hope to increase the max voltage on the rail powering the fan controller with a simple mod. It used to be common for people to step down their voltage for case fans to 7 volts by modifying the +5v rail, I plan on modifying -5v rail to bring the max voltage up to about 17 volts. I know this isn't great for my PSU but hey I wouldn't mind upgrading to a new fully modular one anyways if this one dies.

    Yes it is crude and the picture sucks, but I have all of 3 minutes invested in this so far. I will use a crimped connection and heat shrink in the future, so please don't tell me the wire nuts are unsafe... I know they are. If it isn't completely apparent, I have very limited knowledge concerning electronics.

    [​IMG]

    I mainly did this to decrease heat up times but I hope to use my PC as a primary source of power in the future. Sadly I wont have time to mess with this for another week or so. This mounts in a PCI slot, the back of my PC is more accessible for me. If I can get this to work out I'm going to get a new case and a 5.25" drive bay controller.

    Has anyone else attempted something similar? Comments/Suggestions? Better ways to go about this? Any insight is greatly appreciated.
     
    Last edited: Feb 19, 2014
    vakedcow likes this.
  2. CentiZen

    CentiZen Evil Genius in Training Accessory Maker

    Messages:
    1,722
    Location:
    America's Hat
    Haha, man, you just echoed the exact thoughts that ran through my head when I delved into log vape power supplies. I'm really interested to see where this goes from here.

    I am a little confused on where you are drawing your power from, though. Is this fan speed controller plugged into a molex plug or one of the motherboard fan power headers? Or is it through one of those fancy PCI fan controllers?

    Also, how many fans is this controller rated to handle? I'd be a little worried about overloading it long term since a case fan usually consumes around 3W as opposed to the 8W or so that is consumed by a log vape @ 12v before any losses introduced by conversion.

    Also, do you have a voltage display on this? These little voltmeters are inexpensive and accurate, they would be a great addition so you don't have to use the multimeter every time you want to check your voltage. Keeps your vape safe too, exposing it to 17v would probably do some damage to it.

    Anyways keep us updated, I think this is a really cool and creative idea.
     
    deadheadbill and z9 like this.
  3. Tweak

    Tweak T\/\/34|<

    Messages:
    1,381
    Interesting ideas.

    Got me into digging about using PWM to control voltage.

    How cool would it be to remote into your PC and pre-heat your vaporizer.
     
    z9 likes this.
  4. z9

    z9 Well-Known Member

    Messages:
    712
    This was a shitty fan controller when I purchased it, I have no idea what its rated at. Its set up to handle 3 fans, but I used to power five fans from the controller when I was into water cooling and its still kicking (obviously). Its currently powered from a molex plug, but I have the option to use a 3 pin motherboard header. I only had the vape hooked up to the controller while testing.

    Thanks for the link; I bet I could even mount the meter to the pci slot next to the controller! As of now monitoring the voltage isn't a big deal because it can't go over 12 volts but once I figure out how to increase the voltage that voltmeter will be invaluable to me. I don't see myself ever wanting to go over 14 volts with my UD.

    I think it'll be easier to bring the max voltage to 24 volts but then I'll lose a lot of my adjustment I need in the 10-14 volt range and I risk destroying my log if I bump the voltage or something.

    I thought about using PWM but I don't have the knowledge to delve into this. I can adjust the fan speeds from the OS using the Asus suite, of course this only works for PWM fans connected to the mobo headers. Somebody with the right programming knowledge could probably do something really cool with this idea though.

    My balls aren't quite large enough to connect something to my motherboard that I rigged up; I can get a PSU at Best Buy any time but a mobo... not so much.
     
    Last edited: Feb 20, 2014
  5. VoltageKeeper

    VoltageKeeper Well-Known Member Accessory Maker

    Messages:
    75
    I actually did the very same thing before I designed the VK - I used a computer fan controller I had laying around. The only issue was that it really couldn't go much above whatever voltage you fed it. I ended up opening up a computer power supply and adjusting the trimmers inside to bump it up to something like 13-14v on the 12v line, and then the fan controller had a wider usable range. It was a 4-port fan controller, so it could technically control 4 vaporizers at once, although one of the ports was burned out, so only 3 actually worked! The unit I used was the vantec nexus - specs state it can do 18w off each channel, which is more than enough for most log vapes.
     
    Last edited: Mar 4, 2014
    z9 likes this.
  6. z9

    z9 Well-Known Member

    Messages:
    712
    I was planning on doing the same thing but I don't want to mess with my desktop until my laptop is back up and running.

    Here's my idea for variable voltage without modifying my power supply or lines.

    Use a molex adapter to power a step up converter with a display such as this and set the max voltage at 15 volts or so
    [​IMG]

    I'll power the fan controller from this converter so the max voltage going to the controller is 15 volts or so. Then I'm going to use an automotive voltmeter like this to measure the output voltage from the controller to the log, it may not be as cheap or accurate as the one @CentiZen linked but it'll look so much better and should be very easy to mount on my pc since it has bolts on the back.

    [​IMG]

    So I should be able to adjust the dial on the fan controller and see the output voltage change on the gauge as I'm doing so.

    Is there anything I'm missing here?
     
    Last edited: Mar 4, 2014
  7. VoltageKeeper

    VoltageKeeper Well-Known Member Accessory Maker

    Messages:
    75
    Ah, when I did the power supply / fan controller thing - I was using a spare power supply that was not inside a computer - so I didn't have to worry about messing with my computer or anything like that!

    If you're considering a board like that, you might as well use the boards that I'm using in the VK, and I'm pretty sure CentiZen's now using the same ones in his VVPS as well. They're SEPIC-based and go up OR down, which is nice. So you can put in 12v from your PC and get out anything from 0-30v off this thing. You wire a molex directly into this and you wouldn't even need the fan controller at all anymore. Attach a voltmeter, and you've basically got yourself a primitive VK or VVPS. It's actually cheaper than the unit you listed above as well:

    http://www.ebay.com/itm/Auto-DC-DC-...196?pt=LH_DefaultDomain_0&hash=item4ad09f102c


    Haha, so now the secret's out, anyone can build their own modular power supply! Though that was always the case really, the true time and labor is spent in drilling and assembling the cases, mounting the displays, wiring the switches/pots, etc, and if you're willing to do that labor yourself you can definitely make something highly functional for pretty cheap.

    I could totally see making something primitive with a female molex and a knob that mounts into a PCI slot. That would be kind of neat actually. Although if you're going to mount a big LCD readout, another option would be to put a knob on it with a big length of wire - then you could just mount the knob on the front of the case or something rather than having to reach behind your computer to the slot on the back. Just some ideas anyway.
     
    z9 likes this.
  8. z9

    z9 Well-Known Member

    Messages:
    712
    Thanks for the info and link! I landed on that particular converter because the display would make it easy to set and monitor the max voltage output going to the controller; that way I can alter the voltage without opening my case. Funny thing is I've been looking at finding a knob to mount in a pci slot or hose cutout to replace the fan controller altogether but I'm not sure what exactly I need to do this.

    My PC is actually set up so that the back is nearest to me so for now this will be most convenient, I do have plans to downsize my case in the future and I'll probably have the front facing me once i do, I'll look at 5.25" bay mounting options at that point.

    I would never try to create an enclosed device like the VK or minivvps for the reasons you mentioned, plus my handiwork would never compare to the build quality of an vvps made by you or centizen. It would be easier and most likely cheaper for me to buy a prebuilt unit than to design my own, not to mention I don't know what the hell I'm doing.

    Most vape and desktop owners don't need/want to do this so I think you guys are safe ;)

    Thanks again
     
  9. VoltageKeeper

    VoltageKeeper Well-Known Member Accessory Maker

    Messages:
    75
    You basically would need to wire in a potentiometer to replace the small trimmer that's already on the circuit board. It does require you to de-solder that trimmer and solder some wires in place. A 5k multi-turn pot would probably be the easiest option since it should put you in the 0-15v range.
     

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