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VapCap Induction Heater for Desktop and in Car Use

Discussion in 'DIY' started by Pipes, Nov 23, 2016.

  1. tuuwie

    tuuwie New Member

    Messages:
    13
    When my induction heater used to work, I had it set to position 1 with 5-6 second clicks.
     
    GreenHopper and zhong8051 like this.
  2. phattpiggie

    phattpiggie Well-Known Member Accessory Maker

    Messages:
    2,041
    @Squiby, @Summer, @Ramahs and @Blu. I'll answer your question here.
    This is the way my first Skelly was put together, it's now in the Sumac with a DC jack instead of batteries.
    I'm probably going to make a desk top one up for when I'm in the shed.
    [​IMG]
    After I've finished this Mini version off, apologies for the focus.
    [​IMG]
    All my IH's together for a bit of scale
    [​IMG]
    To get the 'log' style heater involves a reposition of the coil. This is done to keep the diameter down.
    If I was to 'log' a Skelly I would be inclined to put the heater on top of the battery sled, this means I can make an access door in the base. It also means they would end up more cone shaped.

    I'd be happier retro fitting them than sending out an enclosure and hoping that the end user could fit the heater properly.

    No idea on a price or time frame. Not having the tools or space makes them an involved build.
     
    Cl4ud3, Blu, AtomicPB and 13 others like this.
  3. Mr. Me2

    Mr. Me2 Well-Known Member

    Messages:
    2,365
    You’re on the path of our earlier conversation. Love it!!!
     
    phattpiggie likes this.
  4. MAbud

    MAbud Well-Known Member

    Messages:
    370
    @phattpiggie the second you want to retro fit a Portside Mini with a wood enclosure, you let me know!!
     
    Blu, Squiby, Mr. Me2 and 2 others like this.
  5. Ramahs

    Ramahs Fucking Combustion (mostly) Since February 2017

    Messages:
    563
    Location:
    The Internet
    I'd want something like that for home-use, so no battery sled needed. Just DC, as I'd never put batteries in it anyway.
     
    ClearBlueLou and Squiby like this.
  6. tuuwie

    tuuwie New Member

    Messages:
    13
    Hey @phattpiggie, do you change out the FET's on the ZVS Heating circuit too? If yes, which ones have you had good experiences with?

    Thanks in advance
     
  7. rz

    rz Well-Known Member

    Messages:
    177
    @tuuwie
    Look for:
    N-channel MOSFET
    Low Rds ( < 20mOhm?)
    Vds breakdown 40v at least (Lower values *may* work, 60v is even safer)
    Vgs threshold should be low, below 4v.
    Low gate capacitance.

    Look for keywords in the feature description like:
    High-speed switching
    Small gate charge
    Low drain-source on-resistance (Rds)
    Logic level (= low Vgs threshold)
    etc..
    (these may not be featured, but need to be found in the specs)

    What works best for you depends on your specific build ( IH frequency, maximum current draw, power supply voltage and how it responds to current draw)

    Below are some examples of ones that I've found to work well (and are probably over-kill in some aspects). There must be thousands/hundreds available that would work, and if you have any sort of large electronics component store in your area they're likely yo have at least one.

    https://www.mouser.com/ProductDetail/757-TK6R7P06PLRQ
    https://www.mouser.com/ProductDetail/726-IPD079N06L3G
    https://www.mouser.com/ProductDetail/863-NVD5C688NLT4G
    https://www.mouser.com/ProductDetail/512-FDD9410_F085

    So look around for what you can find that looks relevant and ask us what we think.
     
    KeroZen, AtomicPB, Pipes and 5 others like this.
  8. tuuwie

    tuuwie New Member

    Messages:
    13
    Thanks so much for linking me with this info.
    Really appreciate it.
    Will ask around and let you guys know the MOSFETs available here.

    Any chance you guys happen to have a circuit diagram for the ZVS Induction Heater? I have been looking around and haven't found any part numbers / datasheets / circuit diagrams. The ones i've found, I am not sure match the spec of the heater I have thanks to the lack of knowledge on my part. I was looking for it in case I have to take this blown one to a friend to replace the MOSFETs.

    Thanks in advance
     
  9. zhong8051

    zhong8051 Member

    Messages:
    12
    Made new one more compact :lol::lol:. I love making this :rofl:

    Click to play YouTube Video


    Fast click tips

    Click to play YouTube Video
     
  10. rz

    rz Well-Known Member

    Messages:
    177
    @tuuwie
    http://fuckcombustion.com/threads/v...top-and-in-car-use.23211/page-75#post-1220762

    http://kaizerpowerelectronics.dk/high-voltage/mazilli-zvs-flyback-driver/

    in general, google Royer oscillator / Mazilli flyback driver.

    @zhong8051 looking good. Keep up the builds ! :) The fast click in your second video is due to the shallow insertion. Since the bi-metal disc at the end of the cap (that does the clicking) is actually being induction heated itself, it heats up quickly and clicks. This does NOT indicate the actual chamber temperature. It is more likely to result in slight charring of any material touching the end of the cap, and a tip that cools down way too quickly since the rest of the tip doesnt get a chance to heat up enough. Your first video's insertion depth looks much better.

    What are you measuring there, Amps @ 120 / 220 V? Either way thats some powerful stuff. How much capacitance do you have on there? Got an oscilloscope? :)
     
    KeroZen, Paraiso, GreenHopper and 3 others like this.
  11. zhong8051

    zhong8051 Member

    Messages:
    12
    I using step down from 24voltDC to 12volt DC. The ampe meter measuring DC ampe, 4x330nF 400V. I dont have oscillos. What you want see on osc ?
     
  12. tuuwie

    tuuwie New Member

    Messages:
    13
    Wow, that was quick. Thanks so much for sharing this man. Really makes my life so much simpler.
    Will try and swap out the MOSFETs of my busted induction coil and will share the MOSFET components i am able to source here. I am sure it'll be similar to one of the ones you've linked. Thanks again. Much appreciated.
     
  13. rz

    rz Well-Known Member

    Messages:
    177
    @zhong so thats about 7.5A @ 24Vdc? ~180Watts. Assuming 90% efficiency in the step down that's still over 150W delivered to the IH. Those transistors must be getting toasty. You could try reduce capacitance. 0.33~0.66uF range should be good depending on your coil. I'd experiment a little there, maybe use 2x0.33uF in series for 0.66, then parallel with another 0.66 string to give you 0.33 (using just one of those 0.33's alone may cause too much heating in the single capacitor), or just use two in parallel for 0.66uF. Reducing capacitance will INCREASE the self oscillating frequency which will INCREASE switching losses however it will also increase both the capacitive and inductive reactance (Xl == Xc), which causes general current consumption to DECREASE. There's no need to heat up the vapcap TOOOOO quickly, which often results in burnt loads anyway. An oscilloscope will show you the frequency, which should be around 20~30kHz, and help you tune your coil/capacitance, but is not entirely necessary.

    EDIT: Corrected a backward statement about frequency behavior above.
     
    Last edited: May 30, 2018
    frankbhelger and KeroZen like this.
  14. zhong8051

    zhong8051 Member

    Messages:
    12
    Thank for your advice,
    I'm check again, measuring direct input IH, the curent is 14A
    Temperature of transistors is under 60*C I think is not too high because we using IH with shot time.

    Click to play YouTube Video
     
  15. polykoma

    polykoma New Member

    Messages:
    15
    Location:
    Berlin
    yo - but when you have a session then you maybe heat up repeatetly over lets say 3-5 minutes.

    can you simulate a "session" and monitor the transistor temp?

    regards poly
     
  16. tuuwie

    tuuwie New Member

    Messages:
    13
    Just realised I completely missed this post and I am back to report that after careful analysis, the FETs on the heater seem to have cracked and completely busted.
    I am checking for the ones you linked earlier and also for the ones @rz linked as well in the open market for a quick replacement. Hopefully the FETs are the only things I fried and the rest of the heater circuit still is intact.

    Thanks for all the help guys. You guys are awesome
     
    GreenHopper likes this.
  17. phattpiggie

    phattpiggie Well-Known Member Accessory Maker

    Messages:
    2,041
    GreenHopper, V-apE and tuuwie like this.
  18. zhong8051

    zhong8051 Member

    Messages:
    12
    after heating, temperature of FET about 55*C and it cool down fast so I think when we heating again after 1-2 mins it OK ^^

    I think you can DIY 1 heater like me and forget the module you buy on EBAY ^^
     
    Last edited by a moderator: May 31, 2018
  19. tuuwie

    tuuwie New Member

    Messages:
    13
    Good idea. Will give this a shot for sure once I get more confident about these solders.
     
  20. tuuwie

    tuuwie New Member

    Messages:
    13
    In my exploration of trying to fix my ZVS board, I have uncovered lots of info on this build.
    Full credit to everyone on this thread for helping with all the info so far.
    I'd like to share some of the videos's I've uncovered as well for people that might be interested in building their own induction heaters. Doesnt seem too complicated, but definitely needs soldering knowledge and electrical know how.

    Click to play YouTube Video


    This video is by far the best out of the lot. He's even linked a site to get the PCB's printed.
    I think this is a good alternative to buying the ZVS + MOSFET trigger boards as most of these parts should be available in the local electronic market for far cheaper.
    Good luck to everyone
     
    AtomicPB, Mulchmaker, Hogni and 2 others like this.
  21. MAbud

    MAbud Well-Known Member

    Messages:
    370
    Quick question...so I plug in my unit to charge, turn it on and wait an hour or two till the light turns green. However, every time I put the first cap under load and press the test button I only get two of the three blue lights lit up. Am I doing something wrong to not get full charge?
     
    AtomicPB likes this.
  22. Pipes

    Pipes Addicted DIY Enthusiast Accessory Maker

    Messages:
    2,076
    Location:
    Southern Ontario
    Yes, perfectly normal. It should drop at least one led when under the VC load. This is why it's good to check under load for a more accurate reading towards the lower end of charge. Other wise it will show full until the close to the end and drop off fast.
     
    Ramahs and AtomicPB like this.
  23. Joaon

    Joaon Well-Known Member

    Messages:
    259
    Location:
    France
    @Pipes, I have a question :
    My skeletor is behaving weirdly lately, in won't take into account the internal switch that is pushed when vapcap is inserted. I now have to shut it down with the main, or it will overheat.. Red led is now always on also
    Any idea? :shrug:
     
  24. Pipes

    Pipes Addicted DIY Enthusiast Accessory Maker

    Messages:
    2,076
    Location:
    Southern Ontario
    Hmm, it's about 10 months old now, does it still feel clicky when you push down the VC?
    If not, it might be stuck down and needs a good cleaning.
    Take a paper clip and straiten it out. Now use pliers to bend one end to fashion a small hook. Insert between the button and o-ring until it rests low enough to twist the hook under the o-ring and snag it out.
    Grab a couple Q-tips and clean the tube and switch post with ISO. At this point, ensure good clicky action of the switch.
    Now use the cap off a pen or marker to push the O-ring back down the tube to be just under the top of the switch.
    If this doesn't remedy, shoot me a PM as you might need a new switch tube or driver assembly pending your soldering skill level. ;)
     
    GreenHopper, DeeCee5, bossman and 5 others like this.
  25. bossman

    bossman Well-Known Member

    Messages:
    222
    My Jarhead arrived today and I love it. So civilized. Do I leave it plugged in when not in use? I mostly vape evenings.

    Thanks @Pipes!
     
    Pipes likes this.

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