Induction Heater - 6" Coil vs. 1/2" bar
ฝัง
- เผยแพร่เมื่อ 6 ม.ค. 2013
- Updates on this project are being posted on the new Patreon page: / reactorforge
You can also support the future of this project there as well.
Heating a 6" section of a 1/2" bar. The heater is pulling about 1500 watts when the bar is cold and about 6500 watts once it heats up. Much more efficient than my previous induction heater.
For details on how to build your own visit:
github.com/ThingEngineer/Reac...
ReactorForge Blog: blog.reactorforge.com - วิทยาศาสตร์และเทคโนโลยี
![ความรักไม่ได้น่ากลัวขนาดนั้น (TRUST ME) - LYKN [ OFFICIAL MV ]](http://i.ytimg.com/vi/9np-lAtCRpQ/mqdefault.jpg)
I really like your logic with this heater Josh. Nice
Heater's gonna heat!
Such a beautiful setup...
Also the input to the inverter is rectified, unfiltered, pulsed DC which results in a near perfect power factor on the mains side. Slightly higher apparent power output can be achieved with a large filtering capacitor (or bank) but at great cost in mains peek current draw and power factor.
I am interested in making an adjustable induction heater like yours, but I have been searching for a good, step-by-step, from the wall socket to the coil video guide on how to set one up. But I am frustrated because I haven't found a good one yet. Everything I have found so far has either been bits and pieces, or just videos of them working, or very small ones. I would love to see a full walk-through of your setup! I am subscribed, and eagerly waiting for a new video!
It's flexible fiberglass tubbing (non siliconized). It works ok for low usage testing just to avoid accidental contact with test gear and wires but being glass it melts pretty easy so it's not viable for shop usage. You would want a high temperature polymer ceramic coating for that.
Thanks for posting, - I really appreciate all your replies to the questions here.
Most people do not reply and your answers are very helpful to me as a beginner.
Just super. I look forward to building one to heat household use water. Cheers, gk.
Glad you found it helpful. Water heating is a great application for an induction heater and can be easily achieved by configuring the work coil to heat only itself.
Ediphen There is already cooling water flowing through the copper tubes you see wrapped around the steel work piece. With no modification to the machine you can remove the work piece and crank up the power resulting in rapid heating of the work coil. In a real application one would design the coil to contain the magnetic field, or remove the coil all together and re-tune the system. An understanding of the resonant tank will lead you to your answer of how to do it. And as always there is no one right answer here.
Wow that's one hell of A induction heater.Nice touch with the breadboard :D
...and I want to see more of Your projects :)
I am using an LCLR matching circuit in this setup with a step down ratio of 18:1. That high ratio did serve to limit the maximum null load to an acceptable level. However this "high gear" which resulted in built in current limiting (good) but slow heats from cold (bad) was something I wanted eliminated. I did so by lowering the matching transformer ratio to 6:1 and implementing a phase shifting current limiting scheme. I've also switched to a parallel vs series tank setup.
Nice Work
I am releasing the schematics and AVR C code under an open source license soon. I will offer parts in kit form since some of them are hard to obtain in small quantities. We'll see where it goes from there, maybe kit assembly at the least.
@Levi - You can run this on 110. In fact I have it running on 110 now while I'm rewriting the control code to optimize the PI controller and current limiting. I've even ran it off of a couple car batteries, the inverter input can be what ever you like within the limits of the switching device.
Whats the the amp draw on 110
Paint it on or dip the work coil in it. And yes protecting it from shorting out and accidental contact would be the main reason for it in a production environment. The one my brother is using now has a rather small ID coil, around 1-1/4" and he shorts it out constantly, every time he uses it. It makes me cringe when I see it happen but it can handle it just fine. I have not spent a lot of time on finding a good coating solution because it's not a priority but when I do I'll share it.
This man here is a genius!!! Take my money!!!
nice workstation.
Thanks, Josh. Protecting the coils from my old, clumsy fingers was what I hoped to do with it, Would the ceramic coating [I assume you paint it on?] protect the coils from shorting out across the work piece without affecting operation?
Thanks again! Dave
Thanks Josh, you're a star :-)
thats awesome.... how many amps to hold the temp ounce it is hot? thats 1760 watts cold.... why are we not making boilers for the home?
LCLR matching network has a gear ratio that varies with load resistance.actualy when you put a heavy
load into the workcoil the gear ratio will be highest and your current will be low.and reverse in null load. and also your resonant frequency will be change .
Wouldn't it be more accurate to state that rather than the ratio varying (which it doesn't since it's a fixed coil); it's just that the tank is being quenched, in other words the tank excitation voltage is lowered in turn lowering the current draw and thus heating capacity?
This effect is why I lowered the turn ratio on the matching xfmr, to heat larger work pieces. And you're correct the resonant frequency does change but since it is tracked by the micro processor it's not really an issue.
Nice, I think we've all seen this one. We being anyone who has spent any amount of time watching IH vids on TH-cam. What your looking at is a small block of ice with an even smaller piece of metal in the ice at the very bottom or even below the ice in the granite. When the metal heats up it melts and vaporizes a small amount of ice around it. They stop the video before the hot metal has a chance to melt the ice in the visible portion of the cube. I'll post a video reply showing the process.
To clarify power level control is achieved by varying the phase shift of the drive to one half of the bridge between 0 degrees and 180 degrees when compared to the drive of the other bridge leg. This means the power factor seen by the inverter remains good because the inverter is not detuned from the resonant frequency, therefore reactive current flow through free-wheeling diodes is minimized (higher efficiency and less heat to dissipate).
interesting, the wattage to hold that temperature is quite low I couldn't read the read out on the oscilloscope to read the output voltage.... definitely a cool video.
very good video, i brought a 1000 watt Induction Heater for Harding home made tools works good
+Artistic Diyer got it from this website here goo.gl/FS4aiu
Hello,
Can you inform about your 1000W Heater, model, price etç? Have you a video of working?
yes does work good, but you do need a good power supply capable of putting out at least 20a continuously.
or use two or four lead acid battery's in series. not got a video of it working.
Hello
I think your induction board is similar to this one you can see in this link: www.ebay.com/itm/Fine-1000W-ZVS-Low-Voltage-Induction-Heating-Board-Module-Flyback-Driver-Heater/172159923291?_trksid=p2141725.c100338.m3726&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20150313114020%26meid%3Dc5997b77be344f5e840d2cc5b9cf1133%26pid%3D100338%26rk%3D3%26rkt%3D21%26sd%3D201530953163that sending attached, isn't it? (sorry about link but I don't know how to attach an image here)
Your information about the transformer is very, very important.
I want to buy one of these boards to weld (brazing) in small pieces of mild steel. The solder melts at temperatures between 550º - 790º (1025ºF - 1450ºF).
I'm looking for a good power supply of 48 V -. 20 Amp, according to your information.
Pls let me know your opinion.
Thank you
Joao Ferreira
(Portugal)
what kind of schooling or books would you recommend to learn to build and experiment with induction heating?
hey this is awesome man can i build one to melt metal and how can i make the frequency goes up to KHZ
Question: Is the resonant frequency increasing or decreasing when it starts to heat. I am assuming an increase, as it would take more energy to heat the material hotter and hotter.
Question 2: What was the range in frequency change across the heat range visible in that video? Like, how much frequency adjustment occurred for you to hit the resonant frequency from room temp to when you tuned past the resonant frequency?
What is the largest Loop size you could make the coil before heating became impossible or the magnetic field was negligible?
(Size Ratio of Loops to object passing thru loops)
I don't know if I'm asking this right..
Well, I suppose I should of been more clear on my goals. What I'd ultimately like to use it for would be to forge aluminum and cast it. The size of the objects would be fairly decent in size, which if I'm not mistaken requires more volts and amps. The bigger the object the more current induction needs. For example, model airplane engines would be a great start.
@Jose Augusto Rodriguez Martinez: 1/4 inch OD Copper tubbing
@Picobyte: Thanks, and the breadboard is long gone now.
(Not sure why I could not reply to either of your comments. Says linked comment and there is no reply button next to the thumbs up/down. Seems to be a known issue related to the posters google plus account settings.)
Thanks Josh Campbell, it will help me a lot with my thesis project.
Jose Augusto Rodriguez Martinez Your welcome. Working on a thesis though I would expect a tougher question, but I guess it was hidden by the fiberglass sleeve. ;) Still there is a huge current alternating through that part of the circuit, a material with higher resistivity would not be acceptable. The low grade of copper tubing I'm using is not even optimal but does work. Copper alloy 101 should be used (oxygen free high conductivity). If you really want to get efficient a gold plating on the high frequency copper tank parts would result in less resistive losses to heat. In fact it's almost foolish not to do this in similar applications like ICP torches (inductively coupled plasma) where frequencies are many orders higher and thus the skin effect is exaggerated, not to mention the corrosion resistance would be far superior.
Josh Campbell I need an induction heating power supply, what do you recommend?
Owen Chase There are many factors that go into choosing an IH inverter such as application, environment, duty cycle and available input power just to name a few.
O wow
Nice video here...! what's the frequency of the induction loop..?
Thanks, the inverter can operate from 20KHz-120Kz, in this video with this tank its running at about 50-60Khz.
By resonant frequency, you mean the frequency to most excite the atoms in the material? I'm assuming it changes with temperature?
Josh, what are you using to wrap the coils? Do you know what the destruction temp is on the material?
Do you think induction heaters could be better than a coal/gas forge to make blades?
in my setup the inverter sees full sinusoidal current for a wide rang of loads without only need to track the resonance frequency(open loop) and because the linear relationship to load value ,the Efficiency always high
Great build, I'm wondering how much that celem cap cost you and what the capacitance value is? Also, where did you order from?
i will answer your questions , you can add my whatsapp +8613113688127 ,i will tell your more details,
Hi Josh.
What is the material of the coil? Is awesome and really good project.
copper , you can add my whatsapp +8613113688127 ,i will tell your more details,
Cool video, I had a few questions. So you said the "resonant frequency" changes as the material heats up. Is this referring to the AC frequency, and is there a sweet spot for energy transfer efficiency for any given material? Also, why does the inductor draw more current throughout the process? Thanks!
Una pregunta interesante y jamás se respondio
If I had that coil embedded in some type of insulation such as masonry and used as a forge, would it be okay? Or rather, would it do well embedded in the masonry material?
Hi Josh,
I am interested in buying a kit. How much do you think this will cost? $$$ is the prohibiting factor to my hobbies rn. Got the time and the will to learn. Let me know if you are still doing this! Thanks!!
in the other hand you can use other matching networks that not varies with load value. and in this setup the inverter current has a linear relationship with load value (low current in null load)actually you don't even need to track the resonance frequency .I will post a video in youtube
If during induction You use a second coils inducer , with different impulsive frequency (example a sparkler device to produce microwaves ) , You can modify the properties of material ?
I have a question, are you cooling the coil with water system??? and is there a heat difference between 120v to 220v power intake???
Great video. Question: Why does it draw more current when the bar gets heated ?
+Majin Snake Thanks
You could heat up a section of steam pipe with water vapour sprayed into it to make a rocket, or desalination still.
what's the purpose of the space between the bar/coil and coil on itself?
Could a titanium pipe be heated the same way to heat gallium being circulated through the pipe?
Josh, Great Work !! ... I see you have taken a lot of attention to detail, water cooled coil, serious cooling for your drive board. Why do you need so much circuity to create the drive wave? I see a sine wave and a square wave. I would guess the square wave is the main drive wave outside the tank circuit and the sine wave is whats generated inside the tank circuit once you have tuned it properly. I see you have at least 3 circuit modules. I assume you are able to modify each part of the drive signal including frequency. In my mind it seems it could be simpler - what creates the need for so much circuitry? I know you are doing zero crossing detection, etc.
So keeping the frequency at the resonant frequency maintains the temperature and raising the frequency above the resonant frequency raises the temperature? Wouldn't the peak temp. be at the resonant frequency?
I got a question for you. Im building a large still for turning plastic rubber and used motor into gasoline and i want to use a induction heater as a heat source. I have 2 microwave transformers and a large transformer from a forklift charger can i turn these into a heater. My boiler will be 24 to 36 inches wide and and need 800 to 1200 F thanx
There are lots of resources on DIY heaters of all types including induction. Your MOT's and forklift charger could be one building block to an induction or resistive heater (www.instructables.com/id/METAL-MELTER/), but alone cannot just be turned into an induction heater.
Thanx for the link. Thanx for your time
Cool
By this stuff do you mean the LCLR matching/tank topology? Why would you have to decrease it's value? I actually increased it a significant amount because I was blowing IGBT's due to the high dv/dt and current spikes your speaking of. Can you explain what you mean, maybe I'm misunderstanding.
yes my point was LCLR matching tank.in this topology u have to decrease the L match if u want more power , but decreasing this value cause to pass more 3rd and 5th and high freqeuncy harmunic current throw your inverter .this is harmful for solid state device (my mistake high di/dt not dv/dt).
Any update so far? I'm very interested in this project.
sure I will post video and also design precedure soon.yes I was on 4hv. just dont limit yourself to richi burrent induction heater schem.there are many other interesting schems that widly used in commercial designs
Would make a cool looking but unsafe light fixture
Neat!
so i have a question, does induction heater only works on metals>?
Hey Josh....I recently made an induction heater similar to yours...but mine is at a smaller scale...I was wondering of you could help me out with the schematics so that my circuit could work with a higher load to heat larger materials. I would appreciate if you could help me.
I sent you a message with my e-mail address, send me what you have and I'll try to make a recommendation.
Josh Campbell Please send me your email address too. I am taking this as my B.Tech final year project. I really really need some help with the schematics as I am a metallurgy student and I am finding trouble with circuits.
Please send your e-mail address
Hello I'm French and I would like to make an induction heater. I'm looking for plans and schematics for your heater but on your website reactorforge.com there is no information available. Where to find it? Thanks a lot
Verry nice
I also tried that type of ind. heater but it didnt work very vell, i got
some coupling issue, maybe I miss something about it, I would like to
buy your circuit plan if you say ok ???
I've been extremely busy but I will get it up here eventually. github.com/joshcam/ReactorForge
hey josh excellent work. You are using phase shift power control for the power regulation of your heater. I've found a IC UC3876 which is labelled as "Phase Shift Resonant Controller". If i sync the oscillator of UC3876 with the pulse output from the PLL, will i be able to regulate the power by feeding the error amp directly from current transformer output while staying locked in resonance ?
Hey Mohiuddin, thanks! It's still a working progress but come a long way from the first prototype. To answer your question, as long as the PLL is controlling the frequency of the 3876 it looks like it would work. As long as the inverter output does not shift to fast the PLL should be able to compensate (they can be a little slow). How you tie in the current sensing to the 3876 and tuning the delays would be the tricky part.
thanks a lot for the feedback josh!! i'll keep you updated as the project goes on
Let me know what you come up with. I looked at a few other resonant system chips when I was trying to get away from the PLL but couldn't find anything that gave me the low part count which is why I ended up to doing it in software. The phase shifting wasn't something I was shooting for it just came about once I realized it was possible in software.
please try wolfram tungsen test heating. hy im indonesia nice to met you
i need this to heat my room...
It won’t heat your room. It’s an inductor not a resistive element. The inductor itself is cool to the touch. All it does is create a magnetic field.
its my understanding that that iron bar would continue to heat even when submerged in water
I would also be really be interested in the AVR C that you said you were releasing under an open source agreement, if that's possible. I actually live in Shenzhen, China, so if you need anything sourcing here, please don't hesitate to ask
Top de linha 😁
Can you put some scales under the material to see if the weight changes as you activate the heater? Also, have you tried granite inside the heater to see what it does? Perhaps this is how the ancients carved the stone. Your device may "soften" the material.
When metals are heated to a certain temperature, the particles of metal fuse together with oxygen particles. These new particles of oxygen are now being weighed together WITH the mass of the metal. When particles are added, so is mass. It would take are sensitive scale but the difference should be measurable (not sure if that's what you were getting at).
I can't say I haven't tried heating up rocks yet, maybe in an outdoor crucible. Even then not sure I would want to risk exploding hot rocks and molten metal. :)
'
how how the copper pipe to become heater HOT HOT on the metal rod getting normal to low red to high bright yellow
Nice, I would defiantly like to see your setup.
A couple of the requirements I had for this was to maintain isolation on the tank side and to keep the part count/complexity down on the inverter side. I would like a more stable current relationship between loads but I have not been able to come up with one while still keeping the first two requirements. I am quite happy with the phase shifting current limiting but I'd much rather it occurred naturally. Are you on 4hv dot org?
I liked what I had viewed im building a plastic mold injection machine and have done all but wire in a heated tube to melt the media at 425 deg can you help me with a plan to do such I have a control unit thremocoupler and relay the tube I wish to heat is 1.5 id and 10 inches long I have made a ceramic type with a wound kiln element but seeing the induction coil got me thinking to better heater function over all thanks kenneth
kenneth berkley Sounds like a great application for induction heating. I'll be working on finalizing the designs and posting to GitHub soon.
Jack, yes many manufacturers make induction coils that are encased in furnace cement, ceramics or similar materials. Since the coil is water cooled there is no harm in encasing it in anything non-condcutive.
What type of impedance matching network has this sort of current/load relationship? Shoot me a message when you post the video, I'd like to see that for sure.
how current pick to pick (on the coil)? and what is the frequency
i will answer your questions , you can add my whatsapp +8613113688127 ,i will tell your more details,
my resistive hot water heater uses 4500 watts per element typically only 1 at a time... but you just heated more mass than that element in a lot less time to a lot hotter temperature... if this works when submerged, im designing and building my own water heater lol.... dont forget the TP relief valve lol
I have a Lincoln "Tombstone" stick welder. Can I just make a few coils of copper pipe, set it on AC and do anything like this?
heliarche Those output low voltage high current DC or 60Hz AC, no where near the 10's of KHz you need to set up a resonant tank not to mention no way to control the resonant frequency. You also would not want to power an inverter like that in an induction heater with low voltage high current as switching high current is harder to deal with than high voltage. The preference is high voltage low current. Best to just keep using it as a welder. ;)
Right on. Thanks Josh!
Just a question, I'm looking to build one of these, on a small scale to play with, I wanna what kind of power draw you looking at, how power does it use compared to lets say a microwave or kettle?
MorbidSpecter The average microwave draws between 1-1.5 KW. This IH's power draw can be dialed in, if you limited it to say 1.5 KW that is enough power to work on smaller items such small knives, small section of 1/4-3/8 stock, etc. It can be dialed up to draw 25 KW with robust cooling but runs best limited to about 15 KW which is more than enough to heat a few inches of a 3"+ piece of metal in a couple minutes to it's melting point.
Josh Campbell Double thumbs up bro, thanks :)
good
how did you build the heater?
what's the power consumption to run this?
Thumbs up :)
Alex
Nice heater for knife makers!
is that a hollow induction coil with water running through it for cooling?
Yes, without cooling water the work coil heats up. The heat causes the resistance of the coil to rise which causes more heating. The coil would eventually be destroyed due to thermal runaway.
LIKE! I have no knowledge of electric or electronic parts.. Please, tell me how much will costs to build something like this? Thank you in advance.
This could be a pretty dangerous project for a beginner so I would work on that part first. The raw material cost for "something like this" can vary wildly. Some throw together a working version for less than a hundred bucks, this one setting on a desk top with no case, extras, controls or display is about $4-500. Not counting supporting items like an oscilloscope, auto transformer, programers, etc... Understanding electrics and then the circuit will get you the answer to that question.
i wonder. coudl this be used to heat water ? like if a pipe was through the center and either of the hallow pipe lead into the bath tub.
Absolutely, in fact the work coil needs to be cooled by pumping water through it. You could even arrange the work coil in such a way as to cause extreme self heating and take advantage of that to heat water.
Josh Campbell awsome!
how i could make the copper heated like this iron stick in the same this cuircut?
Using the same setup, I have successfully heated copper as well. I used a smaller coil to get a higher resonant frequency and used it to braze other coils! :)
Apparently, I sell induction heaters out of this company in India... nice! (notice the image is taken from this video)
www.autocontrols.co.in/induction-billet-heater.html
I'd probably take a swing at one of these if it was 110 instead of 220. Just don't have access to breaker, etc.
After finding a how-to of sorts, the engineering doesn't look at that complicated. You just need to do the appropriate math to figure out what scale you need. The capacitors, power supply, and how many coil turns are all part of the heat + current math. rmcybernetics has some really great info on the subject!
yep, a lot of very specific parts, slamming stuff together wont work perfectly, what voltage current rating, what capacitance the cap has, determines the inductance and thus turns your coil needs to run it at max power, what coupling you need for a specific power etc
What if you put finger in?
What is the cheapest and easy way to make induction heater to heat 16 mm diameter steel bar? Thanks..
The cheapest way to make one? Start with a DIY controller using a low-cost microprocessor to generate the PWM pulses for the inverter, no display no input other than a start button. When the switch is pressed ramp down the frequency from the maximum, your inverter can handle until resonance in the tank circuit occurs. This can be determined by a variety of methods. Use the PWM signals generated by your controller to drive high-speed switches such as IGBTs or MOSFETs, this is your inverter. The inverter drives an impedance matching transformer. Make the transformer out of toroidal cores or whatever ferrite material you can get your hands on, just make sure it is a material type that can handle frequencies in the kHz range and power levels in the kW range. Make your tank out of eBay surplus high voltage & current capacitors with copper tubing to connect it all. Pump water through all of the tube to cool it. Use a pond pump or a salvaged windshield wiper pump. Be careful with water and high voltage! If you would like more detail, then ask more detailed questions. ;) I'm working on guides to explain all of this in MUCH greater depth with photos and models.
Josh Campbell thank you for your detailed explanation josh. I will be on it.
hello, you can share the project diagrams, thanks
Could you theoretically use something like this for blacksmithing, or would it be better to stick to traditional methods of heating the metal?
You could definitely use this for smithing, but a normal charcoal furnace is better for a more even heat and therefore greater steel integrity.
Hm. What is it about this method that creates uneven heat? Something to do with the design of the coil (like the spaces in between loops) or something inherent to the way the metal is heated?
Lemonschooner The way that the knife is passed through the coil causes some parts to become heated and some parts stay unheated. thus causing an uneven heating.
another disadvantage
of this stuff is that for increasing the output power you have to decrease your matching inductor value and
this is not good beacause the matching inductor supresses the current spiks of the inverter .and when you decrease. it cause this current spiks to damage your transistors(switching loss & high dv/dt)
can this thing heat water if you pass a water pipe insted a iron bar??, of curse a pipe with runing water
Yes, or you could configure the work coil to heat itself since there is already cooling water running through it.
Hello, is it safe to place your finger inside the coils?
Remove all rings and other metals items from your hand first..
The magnetic field typically has no effect on flesh and bone unless, as RT mentioned, you have a susceptor in or on your person. As a safety precaution you should still never attempt to touch or insert any body part into an energized coil. The work coil is galvanically isolated from dangerous AC mains current but the potential between turns should always be respected.
DEAR SIR CAN YOU SEND ME THE SCHEMATIC DIAGRAM AND PARTS LIST OF THIS VIDEO. PLEASE.......?
how much amps?
Dont heat the player, heat the game.
Melting your Ice T.