1000W Portable Induction Heater

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Introduction: 1000W Portable Induction Heater

About: Electromechanical Engineer, Product Designer, Maker. I love to make prototypes and teach others in the process. I graduated from UCF and spent two years working at NASA.

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

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)

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2 People Made This Project!

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4 Questions

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

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.

Ashampoo_Snap_Friday, 11 May 2018_13h18m56s_003_.png

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

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

85 Comments

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.

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.

Can the attachment touch the load? I'm thinking of car repairs, limited space, handheld, the coil might touch the bolt or frame, etc. What would you recommend for this?

Bad design. The heatsink on the ZVS driver needs air flow to cool it - that's why it has fins. This design may work in the short term but it WILL overheat and either shutdown (if the driver has overheat protection) or die (without overheat protection). You can have electrical isolation and cooling by drilling holes in the case (or cutting one large hole and covering it with a fan grille) to allow airflow and adding a fan to keep the air moving. Size (diameter) and capacity (CFM) of the fan depend on the the power level and how long the inductive heater is used at a given power level. At a minimum, the holes for airflow need to match the physical size of the heatsink and the hole for the fan needs to match the fan's diameter. The airflow needs to be over and parallel to the fins of the heat sink.

1 reply

It's not intended to be ran for extended periods of time. It works just fine for 10-20 minutes at a time like this. Look up "Bolt Buster" and you'll see the intended purpose. It is for quickly heating siezed bolts in areas where a flame would be dangerous. As the bolt heats up, it expands and is easily removed. For this purpose, the unit is perfectly fine as it. Sure, better thermal transfer would allow longer periods of time but if you're running it on batteries that won't last too long anyway, there is no point in over engineering it.

the electronics for this is available on eBay for about $35. putting it inside a box when it needs cooling is not a clever idea. after all how will the heat sinks get air flow when they are placed inside a box?

7 replies

How about drilling some holes in the box and installing a pc fan, this would provide adequate cooling.

I had no issues running this 10-20 minutes at a time. It could just as easily be filled with oil for longer usage.

How quickly does it heat up from switching the coil on? I'm thinking about using it with a foot-pedal switch as an alternative to a propane forge, and don't want to just leave it running.

It depends on the load and how hot you need it to be. Just toggle the switch off when you're done. The device is sensitive to slow voltage rise time. If you are going to use a foot pedal, it should connect and disconnect the ZVS driver directly and have a separate switch for the power supply. That way you can leave the power supply on with a fan so the ZVS driver isn't heating up just idling.

That was the idea. The load would be a 1/2" to 1" steel bar, up to about 1200C.

20 minutes is a long time, so what were you heating? if it is a small load like the Exacto knife blade that u heated then there is almost no load. same with the snippers you showed. so what took 20 minutes to heat up? or are you counting that it was on for 20 minutes but u were putting things inside the coil and then taking them out etc... I think you exaggerating about the time. also when there is no load i.e. nothing placed inside the coil, the how much current does the circuit draw compared to some heavy load?

That was not an exacto blade, it was a much thicker steel hobby knife that draws 18 amps. I would not consider 18 amps "almost no load". Everything shown in the video was about 18 amps or more. I didn't mean full load for 20 minutes but to heat up several things within 20 minutes . I don't know why anyone would need 20 minutes full load because most items heat up much quicker than that. The coil draws about 7.1amps with nothing in the coil, but if nothing is in the coil, I shut it off. I have several videos on my channel about different uses for this ZVS driver. I have melted aluminum, made an induction solder pot, case hardened large bolts and more.

One method to isolate a non isolated variac which I used years ago to make a servicing rig for my bench was to take two identical beefy STEP DOWN transformers i had laying around and wiring them back to back low voltage to low voltage sides. The emphasis on step down is to keep some noob from connecting two microwave transformers these as many know are step up transformers and VERY dangerous. Interesting post. Thank you.

2 replies

this heater works on 12VDC to 24VDC at a high current. whats needed is a 120VAC to 24VAC transformer which can supply around 15 to 30 Amps. the low voltage side goes to his rectifier circuit

Yes i know i was just speaking to a method to isolate a variac. My post was a bit tangential.

This is really great and thanks for the explanation that goes along with everything else. You really did a fine job here, I've wanted to build one for years but really didn't quite understand what was involved. I've wanted to be able to re-sharpen and temper the edges of hacksaw blades. I wish there was a way to do it where the entire blade didn't get hot, just the edge. Thank you very much!

3 replies

yes you can heat treat just the edge. you have to shape the "coil". this time it will be a narrow long "coil". length as the blade and instead of piping, make it 14AWG stiff enameled covered copper wire.the blade must fit in the "coil" so make the width of the coil just a little more for the blade to fit in it. This way the magnetic field will be focused on the saw blade. 1 or two turns of wire. if this is not clear ask the question again and I will explain how it works.

what is the cost of a hacksaw blade?

Lowes has two-packs for $3.08

(Our problem is that I use a lot of them everyday because we cut stainless steel and even using oil it will dull several blades just making one cut.)