Induction Heater - 6" Coil vs. 1/2" bar
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- Опубліковано 26 вер 2024
- Updates on this project are being posted on the new Patreon page: / reactorforge
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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/Thi...
ReactorForge Blog: blog.reactorfor...
I really like your logic with this heater Josh. Nice
Heater's gonna heat!
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.
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.
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 UA-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.
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!
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.
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).
Wow that's one hell of A induction heater.Nice touch with the breadboard :D
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.
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.
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 .
Such a beautiful setup...
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)
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.
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.
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
@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
@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
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).
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
You could heat up a section of steam pipe with water vapour sprayed into it to make a rocket, or desalination still.
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?
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.
...and I want to see more of Your projects :)
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?
This man here is a genius!!! Take my money!!!
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.
nice workstation.
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.
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
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
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. :)
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?
why did you not show the complete setup? just to show that induction heating works?
I have a question, are you cooling the coil with water system??? and is there a heat difference between 120v to 220v power intake???
Nice heater for knife makers!
As much as I would love to make one of these, electricity scares me. Even more so after having a cousin who was an electrician get severely injured on the job. Awesome project though. Nice vid.
A heathy fear (and understanding) of electricity is good to have, but don't let it hold you back. Working with power is no different than driving in traffic, stay alert and know the rules. Thank you for the complements!
Sounds like someone screwed up a tag out / lock out procedure
Jacob Jones It's being investigated by OSHA and I can bet my life that his employer will no longer be running his business considering all the negligence going on. Although I think my cousin was somewhat aware of the risk and should have refused to do it. At the end of the day all you want to do is get done and go home to your family, I get that but things happen in the blink of an eye. It really tears me up seeing him like that. I believe it was an elevator transformer that blew up on him and caught him on fire.
Tony A That's horrible, I'm sorry for your families pain. There is alway an element of unknown when working with high energy systems, you do your best to safeguard agains possible accidents. However, no matter how well you follow safety protocols, the negligence of others can catch you off guard.
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.
what kind of schooling or books would you recommend to learn to build and experiment with induction heating?
Would make a cool looking but unsafe light fixture
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 ?
By resonant frequency, you mean the frequency to most excite the atoms in the material? I'm assuming it changes with temperature?
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
what's the purpose of the space between the bar/coil and coil on itself?
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?
Could a titanium pipe be heated the same way to heat gallium being circulated through the pipe?
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
Did you notice a drop in inductance as the iron transitioned from ferromagnetic to paramagnetic as it heated past the curie point?
Yes, you can tell when it crosses the curie point but heating doesn't slow down. In fact, it speeds up (gets easier) since the resistance of the workpiece rises with temperature.
@@ThingEngineer I understand that, it's the eddy current squared, X the resistance of the metal, that determines how much heat is induced into the workpiece, but I was curious about the change of inductance. The only way to tell, would be to put a frequency counter on the tank circuit capacitors, and look for a sudden change in frequency, as it crosses curie point. It should go up. If you put ferrite in the coil, the frequency should drop. Aluminum or copper, should cause a rise. Hot steel should take on the electrical properties of brass, or bronze. Iron is a poor conductor compared to other non ferrous metals.
@@vincentrobinette1507 I didn't answer your entire question. You asked if I noticed a drop in inductance. The short answer is yes technical, but I'm not reading it out. You could calculate the actual work piece inductance based on the current PSC2 inverter output compare register value. The PSC2 OCR is changed dynamically as the phase difference between the inverter current and the inverter voltage shifts in an attempt to keep the frequency operating at the resonant point (keeps inductive and capacitive reactance equal). Since we know the inverter frequency (because we are setting it) you would just use the series resonance circuit formula and solve for L.
@@ThingEngineer Exactly. By just measuring the frequency, it can be calculated by the value of the capacitors who's values don't change, even though the impedance changes with frequency.
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
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,
1500 watts in start and 6500 watts in high temperature.it seems you are using a LCLR matching circuit or similar .a disadvantage of this kind of topology is that the heater will pull huge current when it run at nun load situation.and you have to put a current limiter to protecting your circuit.in fact your heater power has hardly increasing with decreasing of load resistance.
Do you think induction heaters could be better than a coal/gas forge to make blades?
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)
Josh, what are you using to wrap the coils? Do you know what the destruction temp is on the material?
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.
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,
Great video. Question: Why does it draw more current when the bar gets heated ?
+Majin Snake Thanks
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!!
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
Dont heat the player, heat the game.
Melting your Ice T.
its my understanding that that iron bar would continue to heat even when submerged in water
26.6 x 800 = 21280 W.... thats a lot of wattage, but I dont need it that hot, and Im pretty sure more coils would intensify the effect per watt.... I need to research the resonant frequency of iron in relation to its temperature.... thanks for the great video bub, I've been looking for something to work with on induction, most of what I find is the typical mumbo jumbo, but this one has me on good paths
+Durchgebaut He states in the video that he is adjusting as the resonant frequency changes.....
+Durchgebaut not saying I know all about it, but the hotter it gets the less resistance there is which causes it to require higher amperage to heat it any further, that's my take on the video.....
+Durchgebaut I just started playing with ac generators and oscilloscopes in college, we wont be doing this, but Im sure I'll learn a few things that will help
+Durchgebaut my mistake yes the the resistance increases because the molecules are moving further apart.... i would say induction would work very well for on demand electric hot water.....
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
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.
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 :)
Soooo... 26A at 800V p-to-p?
You sure you got that voltage right?
Surely you're not running at 10.4KW?
Great question! The 800 Vpp measurement is across the capacitor in the tank circuit. To calculate input power what we need to look at is the input voltage and current. So 240VAC at 26A = 6,240 watts of total input power. And since it runs at a power factor near 1, the reactive power is near 0 making 6KW the true input power. (KW = KVA, look up the beer analogy for reactive power)
Extra (continuing with the beer analogy):
To get a DC voltage for the inverter, induction heaters and similar machines must rectify the incoming AC voltage. Add filtering to this rectification and you lower the power factor to a point where only about 60% of the total reactive power (KVA) is doing real work (KW). Most companies take the reactive power (KVAR) and add it to the real work power (KW) then display the reactive power or KVA as the machines total power. This number one of the measurement you often see on the front of an induction heater, in its part number, or plastered on its eBay listing. It is NOT the portion of power doing real work or heating power of the unit but the full reactive power. A good rule of thumb, if you see a 15KW induction heater on eBay you should probably calculate for a power factor of 0.6 meaning only 60% of that 15KW is doing real work. So.... 15KVA x 40% leaves 9KW after removing 6KVAR. Pretty sneaky but nothing new.
The reactor forge uses stronger components and a different type of filtering raising the power factor to around 0.96 to 0.99. This means that nearly 100% of the input power is doing real work. When the machine is running at resonance it is extremely efficient and about 95% of the power makes it into the work piece. This is pretty stinking significant especially if you compare it to heating metal with a flame. Consider for a moment how much of a fuels energy makes it into the work piece when burning it and transferring that energy through convection... Hint: you would almost invert that 95%, crazy!
TLDR;
Yes.
Yes.
No, it's running at 6.2KW.
Great answer! Thanks for the clarification. Makes sense now, and an efficiency of 95% is extremely impressive to say the least! I have heard rumors of the sneaky power tactics implemented by most companies especially when it comes to sound equipment, but now I see just how sneaky they're being.
Thanks again!
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.
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!
Wirbelströme / eddy currents
Why are home made induction heaters so slow to heat up the metal? Even the most elaborate setups are slow. I have seen them in manufacturing systems where they heat up a 1/2" steel rod almost instantly.
Wattage and focus. This is spread over a large area with a lot of thermal mass. The systems you are talkning about are liquid cooled so they can handle a lot of wattage and are focussed to rapidly heat only a small area of the bar before the rest is able to heat sink away the energy.
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.
I'd like to build one like that with a little more power to make killer knives.
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so i have a question, does induction heater only works on metals>?
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 this is awesome man can i build one to melt metal and how can i make the frequency goes up to KHZ
DEAR SIR CAN YOU SEND ME THE SCHEMATIC DIAGRAM AND PARTS LIST OF THIS VIDEO. PLEASE.......?
Any update so far? I'm very interested in this project.
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.
Why not use a graphite rod instead of an iron rod? Then enclose the induction coil in a thin sleave of titainum to cause titanium to glow white hot? You could use much lower voltage to generate heat and even better idea would be to line a insulated cylinder with nintinol thermal electric generators with the titainum sleave being positioned directly in the middle with air being forced around it to heat the air. The Nintinol thermal electric generators could then generate the volts needed to operate the electronics to operate the the induction and the electric fan to draw in air through the insulated cylinder. A space heater you can plug in to a wall socket or 12 volt plug or clip to a 12 volt battery to start it up then the space heater becomes self sustaining after Nintinol thermal electric generators kick in. Then you would have a self powering space heater you could use in a tent a camper or trailer or shelter without any fears of generating toxic fumes. 😊
I'm a welder. They use these all the time .
Yep: pre-heat, post-heat stress relief and even forge welding.
so it ends up higher wattage to get that hot, but I don't need it that hot
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
Can a think like this melt metal without it being ruined?
+Artificial Mayo If you were to use it to melt metal you could turn it upright so the melted metal doesn't drop onto your coil.
What if you put finger in?
If so could not a stand alone heater be designed using a capacitor a TEG a fan a electromagnetic pump and a heat exchange coil? Novartis
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!
good
Did you ever release the schematics? or were you still holding off on that? if you released them, where could we get the schematic? Thanks
Kenneth, I'm working on finalizing the board design and schematics for the 3rd version (the one in this video). However the schematics for the 2nd version (the one my brother has been using in his shop for over a year now) is over on the 4vh.org projects forum. Drop me an pm with your e-mail and I'll send them to you.
Josh Campbell - thanks man- really appreciate it. kwilson0122@gmail.com
Kenneth Wilson Just sent it, let me know if you don't get it. Sorry for the delay been a busy week! :)
Josh Campbell Any chance you would build one of these for sale?
I'm working on that, likely in kit form. (Maybe offering kit assembly as well.)
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.
Where would one start to read if one would like to build one of these? Im interested in it for the application of melting cast iron for casting. But someone needs to start with making stuff glowing red im guessing. =)
Hey bud, there are lots of places to start and many different methods consider. If you are serious I would recommend the book "Elements of Induction Heating: Design Control and Applications" by S. Zinn and S. Semiatin. There is some dated info obviously but it lays a strong fundamental foundation. 4hv dot org is also another good resources for some real life examples done by others. I have my first prototype on there that my brother is still using in his shop. He has some more videos of it in action ua-cam.com/video/Gr31QNQfO6E/v-deo.html at one point he had one showing us melting some steel bars down in a small crucible.
So know looked into your 4hv project, skimmed all the pictures and read upon royer, pll, zvs and all what nots and now im really just horribly confused.. *lols* i havent been able to determine the benefits of say your design what seems to be a IGBT h-bridge inverter with a PLL controller *or am i totally wrong here* from say a half-bridge igbt circuit or a zvs circuit (that seems really easy to make though).
Moronicsmurf I get where your at, there is a lot to take in especially with all the diy examples and a myriad of different methods. Educating yourself on them all will help you determine what you need or are willing to tackle based on your end goal. My first one was an IGBT h-bridge with a PLL/Micro controller setup (not counting a small ZVS many years ago). ZVS is an ok place to start for small scale testing (not to say it can't be taken to a larger scale). Although I think that learning how to manually control the resonance and working with larger drivers is a big part of what you need to scale up. My second model uses a single micro controller with no PLL or other complex analog circuitry. But unfortunately I have not had time to document it to the extent I would like to, but I do intent to. I got lazy and wrote the initial code in Bascom, I'm porting it over to C now and improving the PI(D) resonaces control loop as well as finalizing the board design.
Cool
please try wolfram tungsen test heating. hy im indonesia nice to met you
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.
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! :)
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
how did you build the heater?
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.
What's crazy is if you put your clock inside their it would still be cold.