Recommended Posts

I will design an induction furnace of 2kw of power that will be able to reach 1000 or 1100 degrees Celsius, it will be cheap and easy to use for the user, it will be able to heat all type of metals, as long as they are small pieces, and will have the possibility of Control power. I have been reviewing and studying many home projects as well as thesis on induction furnaces and although I do not understand everything completely I think it is time to move to the experimental part.

Share this post


Link to post
Share on other sites

Mr Bond.

Welcome aboard. If you will add your general location to your profile, you may find that there are Smiths nearby who would be Very Interested in your project.

The system that you have outlined, with the capabilities that you have listed, has challenged and frustrated many who have come before you.

Welcome, and I wish you a good outcome in pursuit of induction heating.

Robert Taylor

 

Share this post


Link to post
Share on other sites
First of all I want to separate my project in several steps
power supply
Digital control
User interface
Inverter driver
Tank capacitor coil circuit
Cooling method

POWER SUPPLY is necessary a power supply that can deliver different negative and positive voltages for my analog
and digital circuits that will carry the electronic card, it is important that this source can deliver several amps,
 this power supply must have a good emi filter and If it's tucked inside a much better metal box.
The EMI filter is to eliminate noises and high frequencies that are mounted in our line socket
 since we will be working with circuits generating electrical noise the filter emi is necessary

 

In my case in my laboratory I have a switched source of an old pc but still working
 I think it is what I need since its input has an emi filter
 and is high current has several voltages and is covered in a metal case

 

Fuentes-conmutadas.jpg

On 6/21/2017 at 12:19 PM, Anachronist58 said:

Mr Bond.

Welcome aboard. If you will add your general location to your profile, you may find that there are Smiths nearby who would be Very Interested in your project.

The system that you have outlined, with the capabilities that you have listed, has challenged and frustrated many who have come before you.

Welcome, and I wish you a good outcome in pursuit of induction heating.

Robert Taylor

 

Robert, nice to meet you
I am interested in creating a debate on this project
I have faith that everything will work out
We are in touch my good friend

and yes,i will add my general location 

Share this post


Link to post
Share on other sites

Mr Bond,

Remember please that you have posted this thread in the "Critique My Work" section of the Forum.

l do believe that Members more knowledgeable than myself will soon be asking some VERY focused questions in regard to your design activities.

Please be patient and understanding with us, some of us are very old and grouchy, and do not have the decorum to always handle people gently.

Please take no offense from efficient, aggressive, scientific collaboration.

That being said, how many watts do you intend to pass through that power supply. Just to note that a typical microwave oven is rated for 1.5 kw.

Are you aware of the high current switching devices in tabletop induction cookers? They are called IGBT's (Insulated Gate Bipolar Transistor).

These are commercially available at very significant power ratings.

I may not be able to respond soon, but good luck.

Robert Taylor

Many ridiculed Elon Musk for daring to call himself a "Rocket Scientist".

Share this post


Link to post
Share on other sites
On 6/21/2017 at 1:22 PM, Anachronist58 said:

ny ridiculed Elon Musk for daring to call himself a "Rocket Scientist".

 

This switched source is only for powering the electronic cards and the inverter driver the power supply of the inverter will be another. The switched source for pc must be able to feed our analog and digital integrated none of these would consume a lot of current .... except for the driver for our inverter, then we will speak more clearly about this topic. As far as prices of switched sources in the market are from 19 to 25 $ to 450w I got mine from an old computer

Share this post


Link to post
Share on other sites

Welcome aboard James, glad to have you.

Induction heating is an old mature technology. 50-75 years mature? Guys have been making units for small scale forging and casting for decades. Using the magnetron out of an old microwave to make a jewelry scale melter has been a subject of Youtube, how to videos for quite a few years and I have a friend who built one in the 1980s and uses a version to heat billets for mokume gane.

The problems Robert refers to arise when people who don't know how they work try building their own. I hate to tell you this but reading what you've written here tells me you are pretty much at the bottom of the curve on this project.

You speak in the absolutes of a college student without the experience to know how little you really know. I'm not being insulting, we're all ignorant there is more we don't know than we do know, worse what we do know is probably mistaken on may different levels.

Right now you're just guessing, Grant Sarver bought components and said many times trying to salvage electronics was an expensive, time consuming path to failure building induction forges.

However for a college science project maybe. As a thesis? I really don't think so.

You have a LOT of good research to do before you start experimenting, just the boards are DANGEROUS.

Frosty The Lucky.

Share this post


Link to post
Share on other sites
Quote

Hi, I'm one of those old and occasionally disagreeable folk:D you know there were folk who said "" I've seen one of those horseless carriages and I think I could build one!(and this relates to induction heaters as well) the bulk of those were (with a modicum of respect ) Idiots. as I have no basis to judge you I mean no disrespect here and I'm just playing devil's advocate here.

  1. do you own/or have used extensively one of the numerous types of induction heater currently on the market ?
  2. Of those that are on the cheaper side there are many with similar pricing structures , competitive / reasonably priced yet not cheap ( there may be a reason for this.
  3. China is at the forefront of this technology as each company is required to share both failures and successes with say 100 others who in turn share with 100 more the R&D cost is relatively low compared with the rest of the world.
  4. I hope you succeed with your endeavour and I wish you all the best thereon.

Regards Ian

 

Share this post


Link to post
Share on other sites
9 minutes ago, Frosty said:

Welcome aboard James, glad to have you.

Induction heating is an old mature technology. 50-75 years mature? Guys have been making units for small scale forging and casting for decades. Using the magnetron out of an old microwave to make a jewelry scale melter has been a subject of Youtube, how to videos for quite a few years and I have a friend who built one in the 1980s and uses a version to heat billets for mokume gane.

The problems Robert refers to arise when people who don't know how they work try building their own. I hate to tell you this but reading what you've written here tells me you are pretty much at the bottom of the curve on this project.

You speak in the absolutes of a college student without the experience to know how little you really know. I'm not being insulting, we're all ignorant there is more we don't know than we do know, worse what we do know is probably mistaken on may different levels.

Right now you're just guessing, Grant Sarver bought components and said many times trying to salvage electronics was an expensive, time consuming path to failure building induction forges.

However for a college science project maybe. As a thesis? I really don't think so.

You have a LOT of good research to do before you start experimenting, just the boards are DANGEROUS.

Frosty The Lucky.

Jerry you need to follow this project. 

because some day i will need your help

13 minutes ago, ianinsa said:

 

 

Is true but we have to create our own way

please follow the project and nice to meet you

Share this post


Link to post
Share on other sites
2 hours ago, the iron dwarf said:

2kw is a bit small to be useful for forging, I have a 15kw and that is still small

i know but i can't begin with a 15kw heater  

 

 

Share this post


Link to post
Share on other sites
Digital control the head of my induction furnace .....
The induction furnace in its simplest form is a coil switched to a specific high frequency, and
 I say specifies because this frequency will depend on 4 factors
1 Working coil (tank circuit)
2 Our workpiece
3 Our capacitor (tank circuit)
4 Temperature
Of all this will depend our frequency.
Then we know that the frequency will vary by any of these four factors,
The Digital Control must generate a frequency and must always try to maintain the desired frequency so 
that the max power is transmitted to the part,
My card needs to condition signals and read data as well as generate a control in the inverter and detect signal
 out of pahse and I will design my card with microcontrollers and analog circuits and a PLL.
There are many circuits on the web that show what I am going to do and if any of them serves me I will take it into account

 

Share this post


Link to post
Share on other sites

good morning
I was working on a design with a microcontrol and a pll that I found on the web.
I did not like that the card was so big and with so many elements but it is what there is at least in this first version
Try that the feed tracks were as short as possible to the micro, I think I'm going to generate a lot of noise or harmonics when my inverter is working.

 

1459227594332.jpg

Share this post


Link to post
Share on other sites

when it comes to the why /wherefore and how wrt. electronics I'm in the dark! however I have a 50KVA(whatever that means) induction unit and the ""inverter box"" weighs about 30 kgs. and that seems to be mostly electronics I had been in touch with Grant Sarver in the early days sharing info hence my questions re "have you used one?" one board and some capacitors? if you were closer I'd suggest you come and play with this one! Maybe you should think about posting a thread asking about one near your location then visiting and trying it out? this sort of research can only be positive and hopefully will help you achieve success in your endeavour! good luck Ian

 

Share this post


Link to post
Share on other sites
3 hours ago, ianinsa said:

when it comes to the why /wherefore and how wrt. electronics I'm in the dark! however I have a 50KVA(whatever that means) induction unit and the ""inverter box"" weighs about 30 kgs. and that seems to be mostly electronics I had been in touch with Grant Sarver in the early days sharing info hence my questions re "have you used one?" one board and some capacitors? if you were closer I'd suggest you come and play with this one! Maybe you should think about posting a thread asking about one near your location then visiting and trying it out? this sort of research can only be positive and hopefully will help you achieve success in your endeavour! good luck Ian

 

Thank you my dear friend for the invitation
50KW is very powerful, could you send me photos of the manual or electric diagrams of the inverter to study it?
For now I follow with the design of my inverter one quite smaller than yours.
And with the driver that will activate the igbts

I decided to design the driver that will activate my inverter, I will start deciding which inverter I will use, I think I have in my laboratory all the elements to design a half bridge inverter, for now I will design one of half a bridge because I do not want to burn many mosfets or igbts
My driver design will be able to deliver enough power if necessary to my devices, so that they can turn on or off in a short period of time, they will also have to have different sources for each power transistor.
As I do not want to have noise or ringging problems in my gates, my driver should be as close as possible to my inverter.

and connect a good resistor to the gate.

 

Share this post


Link to post
Share on other sites

I decided to design the driver that will activate my inverter, I will start deciding which inverter I will use, I think I have in my laboratory all the elements to design a half bridge inverter, for now I will design one of half a bridge because I do not want to burn many mosfets or igbts
My driver design will be able to deliver enough power if necessary to my devices, so that they can turn on or off in a short period of time, they will also have to have different sources for each power transistor.
As I do not want to have noise or ringging problems in my gates, my driver should be as close as possible to my inverter.

and connect a good resistor to the gate.

OK

I chose to use igbts instead of MOSFET I think high currents work very well and my frequency of oven work will be low so I do not see problems
The inverter will have the configuration of half bridge that means that we will carry 2 igbts and two capacitors that I got from mouser
I have thought to use red snubber to remove any peak but until now I will not use it

 

i19.JPG

Share this post


Link to post
Share on other sites

good day
To power my inverter I will use a rectifier of 30 amp 800v this leftover but I do not see the problem,
I need to design my tank circuit, there is too much information on the web I think of designing one with small capacitors since the capacitors for induction furnaces are expensive. And my coil will use copper tube to be able to circulate water and not be damaged.
I will try to generate a resonance frequency between 80khz and 60khz ...
We'll see what happens

DSC_0231_1.JPG

Share this post


Link to post
Share on other sites

Our best induction heater was a 30kw unit made by Ameritherm. If I was going to build one I would pull up one of their electrical schematics and study it. They are a good company to work with and have a very good tech help department.

Share this post


Link to post
Share on other sites

good morning friends.
cooling system
I have seen on the web, different cooling systems that are very expensive but effective, I think I will design mine based on heatsink and fans, I need fans with high airflow and a radiator about 24 or 36 cm
A small water pump
We'll see if it works the way we want and how effective it is,
We need this water passing through our tank circuit and since we will work with water system we are also circulating through the heatsink of the inverter so that they are always in good condition.
In the event that water does not pass through the tank circuit it would heat up to self-destruct

20170626_101212.jpg

20170626_101227.jpg

20170626_101240.jpg

Share this post


Link to post
Share on other sites
23 hours ago, ThomasPowers said:

Sounds like a job for a small old swamp cooler if you are in an area with low enough humidity.

you are right haha

 

Share this post


Link to post
Share on other sites

I turned on and after several attempts and adjustments and burned igbts I could put to work the induction heater could melt small pieces of bronze copper aluminum and iron in 1 or 3 min I guess that's a long time, 80gr
I want to make a new design and design a better control, a better capacitor tank since this does not convince me for higher powers
I plan to keep the same cooling system and also keep the same half-bridge inverter, I want to change the high-frequency transformer
We'll see what happens

DSC_0233.JPG

DSC_0266.JPG

DSC_0348.JPG

DSC_0349.JPG

DSC_0234.JPG

Share this post


Link to post
Share on other sites

I have bought a special capacitor and I have also worked on a better control circuit cheaper and better, I'm still with the half bridge inverter, I have a pretty good power control and my heatsink works very well.

 

Share this post


Link to post
Share on other sites

I already have the new design ready with power control and a much better tank circuit the system has changed a lot and with notable improvements.
Out of the tank capacitor everything else is very economical
This version work with 15 amp 115 ac
And behaves very stable
I have to upload video next time

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.