Build An Induction Heater And Become A Metalsmith

April 8, 2012 by 84 Comments

If you’ve ever wanted to forge, cast, or smelt metal, this project is right up your alley. It’s a 30 kVA induction heater built by [bwang] over on Instructables. It gets hot enough to melt and forge steel, iron, and aluminum.

An induction heater operates by surrounding the object to be heated with a coil carrying high frequency AC current. Basically, the entire setup acts like a huge transformer with a shorted secondary. To get these currents into a workpiece, [bwang] used a TL494 PWM controller as an oscillator. The output of the TL494 is filtered and amplified a few times to generate a huge amount of AC current.

Larger versions of [bwang]’s induction heater are found in foundries and forges all across the land; even though this small version sucks down 50 A out of a dryer or stove outlet, induction heating is very efficient. We’re actually wondering why we don’t see many home blacksmiths using induction heating, so we’ll leave that for our readers to discuss in the comments.

[sessions] reminded us of this induction heater from a few years ago. A little smaller, but still usable.

A Simple Induction Heater

October 27, 2011 by 23 Comments

For those of you not familiar, an induction heater is a device capable of heating something up very rapidly using a changing magnetic field. [RMC Cybernetics] decided to build one and was nice enough to write up the project for the Internet’s learning and amusement. A full explanation as well as a schematic and build instructions are provided on their website.

This heater works using a principle involved in most transformers. When there is a change in the magnetic field near a conductive object, a current will be induced in it and it will generate heat. Interestingly enough, while transformers are designed to minimize this heat, an induction heater instead aims to maximize this heat in whatever object is placed within the coils.

[RMC] Has provided a video of how to build the heater as well as it in action after the break! Skip to to 1:42 to see the heating in action. Or watch the whole thing to see how it’s built.

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Update: Custom Cellphone Induction Charging

August 1, 2010 by 12 Comments

This is a custom back plate with induction charging circuitry that [Derek Hughes] build for his HTC HD2 cellphone. When we checked in with him last week he showed us how to add an inductive charger without voiding the warranty but it wasn’t very pretty because the stock back plate blocked the inductive field and couldn’t be used. The solution he came up with will work with any device if you want to put some time into the build.

He took two different aftermarket cases; one fits his cellphone and the other is a BlackBerry case meant for housing a credit card. After cutting a hole in the back of the cellphone case he epoxied the credit card holder in place, smoothed the seam with Bondo, and repainted. Not only does the charger fit in the credit card case, but there’s still room for a credit card. [Derek] also measured the magnetic fields around the circuitry and found they will not damage the magnetic strip on that American Express Black you’ve been keeping on you. In the video after the break he mentions the last step in finishing this case will be to locate a 90-degree USB plug as the current connector is a bit of an eyesore.

[youtube=http://www.youtube.com/watch?v=DgNOqJBSKmQ]

Homemade Induction Generator

July 13, 2010 by 33 Comments

[youtube=http://www.youtube.com/watch?v=RTTgLYzfQrE]

[Tyler LaVite] tipped us off about the generator he built. He combined a 5.5 horsepower Honda motor with a 10 horsepower electric bandsaw motor. To get an induction generator to produce alternating current you must feed electricity into the system to start the magnetic flux. [Tyler’s] solution was to include a bank of capacitors totaling 230mF which charge from the motor, then release back into the system. It’s not as green as the syngas generators we’ve seen since it still uses fossil fuel, but it reuses old parts sending less to the landfill.

1000W Induction Heater

June 4, 2010 by 63 Comments

[Tim Williams] likes to heat things up with this induction heater he built. At peak it can use 1000W and as you can see in the video, that’s more than enough power to heat, burn, and melt a plethora of different objects. The case design uses a center divider to isolate switching noise from the magnetic field with the whole unit housed in aluminum because it won’t heat up from stray magnetic fields. He’s selling plans and kits in case you want one, but we just don’t know what we’d use it for.

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Induction Furnace

June 22, 2009 by 19 Comments

induction furnace

[Tim Williams] made his own induction furnace. A copper tubing coil forms the primary winding, as the material to be heated becomes the short circuited secondary. The load material is subject to high power magnetic fields operating at radio frequency. The rapidly changing field induces current flow within the material, creating a great deal of heat. The brute power required a cooling system to match. In the video below, the induction furnace can be seen melting common table salt.

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Pendulum Powered Battery

February 8, 2026 by 22 Comments

While the average person would use a standard charger to top off their phone, [Tom Stanton] is no average man. Instead, he put mind to matter with an entire pendulum battery system.

Using the inductive effects of magnets on copper coils, [Tom] found the ability to power small components. With that in mind, the only path was forward with a much larger pendulum. A simple diode rectifier and capacitors allow for a smoother voltage output. The scale of the device is still too small to power anything insane, even the phone charging test is difficult. One thing the device can do is juice up the electromagnetic launcher he put together a couple years back to hurl an RC plane into the air.

The useful applications of pendulum power storage might not be found in nationwide infrastructure, but the application on this scale is certainly a fun demonstration. [Tom] has a particular fascination with similar projects where practical application comes second to novelty. For a perfect example of this, check out his work with air powered planes!

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