1000W Portable Induction Heater

by Proto G

200K756120

Intro: 1000W Portable Induction Heater

Hey guys, this is my portable induction heater that can be powered either with batteries or connected to a power supply. You can use this to heat metals well above 1500 degrees Fahrenheit. I have made different attachments for cooking, releasing seized bolts, a solder pot attachment, and more. Take it camping or just use it around the shop to heat up different materials.

STEP 1: What You'll Need

1. ZVS Driver

2. 6"x6"x4" Electrical Junction Box

3. Three 4S LiPo batteries

4. Heavy Duty 6 AWG Wire for output

5. Heavy Duty Toggle Switch

6. Binder Clip

7. 20A Input Power Cord

8. Thick walled heat shrink tubing

9. Large Strip Terminal Block for attachements

10. LiPo Battery Charger

STEP 2: Cut Four Blocks of Plastic.

STEP 3: Press in Threaded Brass Inserts With a Soldering Iron.

STEP 4: Attach Standoffs From the Opposite Side of the Blocks.

STEP 5: Attach the Standoff Blocks to the ZVS Driver.

STEP 6: Glue the ZVS Driver Into the Base of the Enclosure.

STEP 7: Drill Holes for the Cable Glands, the Switch, and the Binder Clips.

STEP 8: Bend Out the Binder Clips and Drill a Hole in the Center.

STEP 9: Final Assembly

After feeding the cables into the cable glands, tighten them to the enclosure. Use screws and nuts to attach the binder clips and velcro to attach the batteries. Use a few layers of heat shrink tubing to your output cable to make the area for gripping more rigid. Use the terminal strip block to attach your coil to the hand wand.

STEP 10: Taking It a Step Further.

After you have finished assembling the battery powered version, there are a few thing you can do to upgrade your unit. You can make an adapter that will allow you to use a high power 24VDC-48VDC power supply.

If you choose to go the power supply route, you must use two different switches to improve the reliability. One switch to turn on the power supply and another switch to apply power to the induction heater. The power supply should be turned on first and then you can turn on the power to the induction heater. The reason is that most cheap switching power supply don't reach their rated voltage quick enough to kickstart the oscillation of the circuit. This causes both of the MOSFETs to latch up and catch fire. The same will happen if your supply or batteries drop below 12V under full load.

Do not turn the unit on with something in the coil as this can also damage the unit.

You can also design different attachments for different uses. I've salvaged a coil from an induction cooktop as well as made my own cooktop coil. In addition to that, I've made an induction solder pot.

STEP 11:

That's it guys! Let me know if you have any questions or comment.

Please vote for me if you liked this instructable or found it useful!

Until next time,

Anthony(Proto G)

97 Comments

ve6cmm 7 years ago

Thank you for your response.

I haven't seen your previous projects, and I would think that many others that have seen this project and not the others might just follow your example.

I have variacs, and none of mine are isolated. I don't think the typical hobbiest would have one like yours, as they are quite expensive. Stating that these things should be isolated from line voltage should have been mentioned. There are liability issues that you may not be able to shrug off. My comment stands - THE PROJECT SHOULD BE ISOLATED FROM THE AC MAINS.

Thanks for the information about the batteries. I did not realize that they could pack such a punch. I'll have to look into those for some projects of mine.

I mentioned the cooling simply because the suppliers on EBAY mention that it should be done. It makes sense to me as well. It's simple to do, and may prevent the copper tubing from melting. After a few minutes of heating, I can see that the copper could become quite hot and possibly melt. It has been stressed simply by winding it, and that can make it weaker.

I have designed many items for communications, instrumentation, electrical, and industrial applications. I can see from the instrumentation in your shop that you know what you are doing, for you, but the idea when designing something potentially deadly, and this is by UL, CSA, and CE standards, you need to design it for the less technically informed.

I like the project, don't get me wrong, and I am going to build one. Even though I will most likely be the only one that may use it, I am still going to make it safe for anyone to use. We all make mistakes, especially when we are trying to do something quickly.

Oh, I have seen short pieces of wire go up in smoke, even though they can carry large currents for short periods of time without heating up too much. In this case, you aren't even fused, so if your mosfets shorted out for some reason, that little piece of wire would flame out in 1/2 second. I guess you call that a fuse?????

ve6cmm 7 years ago

All I am trying to say is a lot of the people on Instructables do not have the knowledge or experience that you and I do, and that needs to be taken into consideration. I have never seen any of your Instructables until this one showed up in my inbox today. It has solved a problem that I run into once in a while when working in my shop. I'd often thought of building a system like this, and your project has saved me a lot of time.

However, I am sure that others have seen this that don't have our experience and are going to try to build it. You might want to mention the safety aspects of your projects so you can CYA.

The project is great. I know I am going to use it. How long it will be running for, I am not sure. But these things can be used for bending steel pipe, copper pipe, aluminum pipe into very nicely curved pieces, and maybe even square tubing. I build a lot of prototype electronics, and often have to come up with something unique. That's what I am hoping to be able to do with this. I may end up having to build a much larger system to do some projects, but this is a very good start.

Thank you for the kick in the butt and the inspiration to build this.

Also, have you tried changing the frequency of operation? I know some of the really big systems have a variable frequency so that they can get higher efficiency with different materials.

Proto G 7 years ago

I didn't even write about my power supply in this instructuable so there was no need to even mention it. I intentionally left the power supply out as this is a tutorial how to make the portable battery power unit. As far as pipe bending, a steel pipe will work fine but you definitely will need to insulate the coil with fiberglass sleeving to prevent it from shorting out. Copper and aluminum will heat up but much slower than steel but you can build a fixture that has a steel or graphite sleeve that the pipe can slide through to speed up the heating. Industrial units are much better than this because you can adjust the frequency. This unit is self oscillating so the frequency will change depending on what you place in the coil. As the parts you place inside get larger, the inductance will raise, thereby decreasing the resonant frequency of the LC tank. Nice talking with you!

MatthewM176 2 years ago

Hey,

I'm a mechanical engineer and I'm building this with a power supply so i don't have to recharge batteries every use. I know some of the dangers of doing it this way. It would be really helpful if i could get some info on how exactly you built the power supply. I ordered the same capacitors and different but higher rated rectifier. At this point, i need to know the inductance of your toroids. I think from there i know how to hook the rest of it up with no issues. If you could message me directly on here, that would be amazing.

willtoolman 7 years ago

"so if your mosfets shorted out for some reason, that little piece of
wire would flame out in 1/2 second. I guess you call that a fuse?????" -from ve6smm

Fusible links, car manufactures use them, why can't everyone else?

When using AC mains in anything fuses/circuit breakers should be used on the device designed i agree, even if only used by you the designer unless you have really good fire insurance and or life insurance. Just couldn't help commenting on the fact that this practice is used in other things. use a smaller section of wire that is rated to barely passes enough current for normal operation so any over current burns it up and breaks the circuit. Troubleshooting nightmare on cars. and even i do not even agree on the practice from a safety standpoint. And i am a person that does not believe in safety as propagandized by the sue happy want-a-be mama boy society we live in now.

hope this was nice and constructive enough for this forum but sometimes we get splinters and scratches and we just need to suck it up buttercups

ve6cmm 7 years ago

Hi willtoolman,

Yes, fusible links are used in cars, and they do protect circuitry, and they are designed for it. It's also low voltage, which does not arc for any great distance. A piece of wire isn't designed as a fusible link. I guess you have never seen the results of a wire being over stressed by much more power than it has been designed for. First, you smell some hot plastic, then you see flames. Turning off the power does not help. My neighbor had his whole dash in his Chevy truck go up in smoke because Chevy ran the wiring loom so tightly across a piece of steel supporting the dash that it cut through, shorting 28 wires out, and they burnt back over a foot. This is apparently good fusable link application! It worked wonderfully. Chevy could sell another $1000 wiring loom! Exactly what they want - protect their income.

If it was no big deal, like you suggest, maybe we don't need fuses at all? I could be wrong about that, but I don't mind spending an extra buck or two to do it right.

I guess doing things properly and safely isn't a big concern for some. I have bypassed protection circuitry and fuses in my own equipment when testing, or if it is in a "one off", short term piece of equipment, but I would never suggest not fusing a piece of line powered equipment in an Instructable.

Proto G explained why he did it, this was an extension to one of his earlier projects, which I had not seen. I have been a member of Instructables for years and never saw his previous posts. I looked back through his many Instructables and found even more info on this project. The one using a 300VDC PWM supply was very good, and the heating element WAS isolated from the line and appropriately protected.

It seems bot the and I know better as to how to appropriately protect equipment. Many newcomers and backyard mechanics may not. Going super cheap is NEVER a good idea.

Proto G 7 years ago

It absolutely should be isolated like mine is if you are powering it off a power supply. My variac is fused and is where my unit will be used most of the time. I don't have the need to use the battery too often but it's nice to have. The MOSFETs would fail way before that wire ever got even close to hot but the fuse is a nice addition if you want to give your circuit added protection. The copper will never even get close to melting if you just put fiberglass sleeving over the coil or insulate the crucible like I did when I melted aluminum in an older video of mine. Even without the fiberglass sleeve it would be impossible to melt the copper from radiated heat with only 1000W. Again, the cooling is to protect the circuit, NOT the coil. Cooling is only necessary if you are going to use it for very long periods of time. What is your intended use?

raszpel 3 years ago

That you for you project I am stuck living in a nursing home, I have been thinking on building a small inductive burner to heat about 450ml of liquid to use in my room. I am some what new to inductive heating, I am used to working with resistance heating projects. How many amp did you need to send to your ZVS induction heater to get the burner to heat water or maybe lightly fry meat. If I were to use a small approximately 800 watt inductance burner coil how many amps or what size ZVS unit do you think I would need. I do not want to over build this so I can contain most of it safely and neatly. Do you think a 300 watt ZVS would heat your induction burner coil. I would appreciate anyone's feedback or input.

vaibhav tripathi 4 years ago

Can i get the deatils of the components and the circuit diagram of the heater ???

vanran218 4 years ago

with the right safety precautions can i melt lead in this?

hardlec 5 years ago

How big of a battery would be needed to melt an aluminum can? Or a dozen cans (cut up?)
I want to fill some fire ant colonies with molted aluminum.

JimE91 6 years ago

I have a 30 amp rectifier for electroplating. Would that work as a power source for this? Maximum voltage on the dial is 30 volts.

Technicsau 5 years ago

Yes that would work well,specialy if it is a transformer based unit with a large capacitor in it! The smoother the better.

NARENDRA LAAD 5 years ago

I have to make a project to red hot mild steel about 900 to 1100 degree celsius can u give me the circuit diagram and the specification of components

tlxthai 5 years ago

I want to make a small boiler that will be used in a car. I think your pancake coil will work the best. The boiler should be permanently positioned on top of the coil. Can I put a switch on the coil or does the coil need to be connected when the unit is powered up? If the coil and the boiler have to be seperated this will make it much more complicated.

Kind regards,

Mike

DavidW785 5 years ago

https://www.pinterest.com.au/pin/733875701753944757/. Hi can you please tell me what power supply i would use with this style of induction unit? As in the way it is shown to do it with the microwave bits it does not tell you what power supply i should use with it. Hope you can help me out on this one.

inswlkes 6 years ago

Hey Proto G...Thanks so much for your induction videos. I built a version of this with the ZVS driver that SainSmart sells off their website. I also am using the Mean Well power supply. I've got some strange voltage and current readings I was hoping you might be willing to comment on. When I turn on the power supply on its putting out ~39v (I have it turned down). As soon as I switch on the ZVS driver, the voltage drops to ~2.5v and the current spikes to ~27A. Nothing is inside the coil. I'd appreciate your feedback. Thanks.

richardk1985 6 years ago

Can a 12v car battery be used as a supply?

itsmescotty 6 years ago

I've got an induction stovetop that didn't work when I got it (NEW) so they sent out a guy that didn't know anything about them and he had to 'Phone home" for instructions. They had him to some voltage checks and one was incorrect so they sent me a new power board. I removed the old one and noticed both boards (one for the left two burners and one for the right two burners) were setup as MASTER. Supposed to be one master and a slave. Put the jumper where it was supposed to be for the slave board and it fired right up. So the new board was a freebee and I want to use it as an induction heater. One 'burner' is 5700 watts and the other is 4500 watts. Board is powered by 240VAC.
My question is: What determines the number of turns and what size should the coil be?
Scotty
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