I was watching a simple circuit tutorial on youtube where they built the cheap induction coil for heating small metal objects.

My question (which is probably a simple answer) is how does the powering of this circuit work? If the input voltage is 15v then i could just get a 12v 10w power supply and output dc using a few diodes and capacitors.

The video shows he was drawing 2 amps from his expensive bench supply but at 10w and 12v then i wouldn't get more than 0.833 amps.

Will the transformer just keep increasing current on the primary coil until something melts and would require some current limiting circuit?

 

hi clinton,
Please post a link to that video.
Induction heating is AC powered.
E

 

I was watching a simple circuit tutorial on youtube where they built the cheap induction coil for heating small metal objects.

My question (which is probably a simple answer) is how doea the powering of this circuit work? If th input voltage is 15v then i could just get a 12v 10w power supply and output dc using a few diodes and capacitors.

The video shows he was drawing 2 amps from his expensive bench supply but at 10w and 12v then i wouldnt get more than 0.833 amps.

Will the transformer just keep increasing current on the primary coil until something melts and would require some current limiting circuit?

You couldn't melt butter with 10W!

Look at these circuits, Induction Heating .
http://danyk.cz/index_en.html

 

hi clinton,
Please post a link to that video.
Induction heating is AC powered.
E

It was focussed around the induction coil module that he reverse constructed. Input voltage is 12v dc and the circuit creates the resonance to pit ac through the inductiin coil.

https://m.youtube.com/watch?v=_v5Hg...IwAHoECAoQAQ&usg=AOvVaw1fhiPhmqw4h6gDQzEPuZYI

 

Not everything presented on YouTube is related to reality. AND the only parts that you can see are the ones shown to the camera. Induction heating is a bit more complex and takes more power than 10 watts. At least in the real world it does.

 

It was focussed around the induction coil module that he reverse constructed. Input voltage is 12v dc and the circuit creates the resonance to pit ac through the inductiin coil.

https://m.youtube.com/watch?v=_v5Hg2zfLjs&sa=U&ved=2ahUKEwiItrvbn8reAhWNsKQKHRlgCVAQtwIwAHoECAoQAQ&usg=AOvVaw1fhiPhmqw4h6gDQzEPuZYI

clintonb sry but link is invalid! Plz just copy addy from address bar while video is playing!

 

hi clinton,
Please post a link to that video.
Induction heating is AC powered.
E

ericgibbs Just FYI L-heating circuits aren't necessarily AC powered but coil is defiantly driven by high power, high freq AC (so depending on load and app, freqs of just a few kHz to like 5 MHz). So driver is basically high pwr osc or sometimes freq agile SMPS topology

 

ericgibbs Just FYI L-heating circuits aren't necessarily AC powered but coil is defiantly driven by high power, high freq AC (so depending on load and app, freqs of just a few kHz to like 5 MHz). So driver is basically high pwr osc or sometimes freq agile SMPS topology

The heating coils are driven with higher frequency AC, but the power for the drivers may be any "whatever". But the part that does the actual inducting must be an alternating current of some frequency.

 

[

"Aleph(0), post: 1323041, member: 263438"]clintonb sry but link is invalid! Plz just copy addy from address bar while video is playing![/QUOTE]

 

[

"Aleph(0), post: 1323041, member: 263438"]clintonb sry but link is invalid! Plz just copy addy from address bar while video is playing!

[/QUOTE]

What I got was an introduction to some fantastic beasts video.
But Aleph (0) is exactly correct about what induction heating is. A high frequency varying magnetic field generates circulating currents in a conductor and that in turn causes resistive heating. The exact arrangement of any particular instance is sort of complex. So ten watts into a coil is not going to heat very much to any very warm temperature.

 

I guess you could use your music system as induction heater???

Some amplifiers output 100's of watts . I guess it's just a case of making 2 coils of the right impedance to connect where the speakers usually go , and feeding in a sine wave?

 

I guess you could use your music system as induction heater???

Some amplifiers output 100's of watts . I guess it's just a case of making 2 coils of the right impedance to connect where the speakers usually go , and feeding in a sine wave?

There is a serious consideration about using a music rated amplifier for this application, because music , no matter how loud, is not a constant 100% duty cycle. Heating with a 100% duty cycle such as a constant sine wave will heat the amplifier a lot more than music.So I would not do it for more than a very few seconds, at least until you can see how much the amplifier heats up. Also, the power supply may over heat,

 

Here is a 650w one that works.
http://kaizerpowerelectronics.dk/general-electronics/royer-induction-heater/
Max.

 

Here is a 650w one that works.
http://kaizerpowerelectronics.dk/general-electronics/royer-induction-heater/
Max.

Certainly interesting, and an example of what can be done, but nothing like a typical audio amplifier. My point being that yes, an induction heater can be simple, but no, don't use your stereo amplifier for this.

 

EDIT: @MisterBill2 Just so you know, I only left this post intact 2 avoid looking like cowardly hypocrite sweeping my snap judgments under rug! So anyhow when I read further on thread I saw my whining was totally unfounded! So I'm totally sorry for that!

The heating coils are driven with higher frequency AC, but the power for the drivers may be any "whatever". But the part that does the actual inducting must be an alternating current of some frequency.

MisterBill2 that's exactly what I just said! Since ur bothering 2 quote my text I'd definitely appreciate u showing courtesy of taking a moment 2 read it b4 making comment! So I'm sry to sound bitchy but that sort of condescending inattention is just RUDE!

 

What I got was an introduction to some fantastic beasts video.
But Aleph (0) is exactly correct about what induction heating is. A high frequency varying magnetic field generates circulating currents in a conductor and that in turn causes resistive heating. The exact arrangement of any particular instance is sort of complex. So ten watts into a coil is not going to heat very much to any very warm temperature.

MisterBill2 sry I missed quoted text (from post #10) b4 complaining abt post #8 Anyhow my tude was definitely nothing personal! It's just me having a Kentucky Fried Crow (by which I mean too impulsive) day

 

I guess you could use your music system as induction heater???

Some amplifiers output 100's of watts . I guess it's just a case of making 2 coils of the right impedance to connect where the speakers usually go , and feeding in a sine wave?

There is a serious consideration about using a music rated amplifier for this application, because music , no matter how loud, is not a constant 100% duty cycle. Heating with a 100% duty cycle such as a constant sine wave will heat the amplifier a lot more than music.So I would not do it for more than a very few seconds, at least until you can see how much the amplifier heats up. Also, the power supply may over heat,

Also problem with exciter+amplifier setup is you'll need someway of keeping it matched to Z of load (which is constantly changing with temp and geometry and like that) so that means automatic _tuner_ which is big hassle and not perfect solution anyhow cuz shifting magnetic properties of load really need changing freq for best result! So u could do that using smart AFC on exciter w/ broad-band pwr amp but way better solution is to just use pwr oscillator with load (which is coupled though coil) as part of resonant circuit!

 

MisterBill2 sry I missed quoted text (from post #10) b4 complaining abt post #8 Anyhow my tude was definitely nothing personal! It's just me having a Kentucky Fried Crow (by which I mean too impulsive) day

I did wonder about the intensity of your response, since I was certainly not trying to belittle or ridicule anybody. That is just not the way I am.

Now for induction heating, optimizing coupling and load matching for best efficiency will make it possibly MUCH more efficient, but with enough power available it is less critical to optimize the efficiency to deliver enough power.

 

Now for induction heating, optimizing coupling and load matching for best efficiency will make it possibly MUCH more efficient, but with enough power available it is less critical to optimize the efficiency to deliver enough power.

MisterBill2 that's what's perfect abt resonant pwr osc for work coil driver (like _Mazilli Royer_ which is sometimes WRONGLY called ZVS) cuz it's totally self matching and _optimal freq seeking_! So o/c other topologies work too including _freq tracking_ SMPS but I say that's impractical for apps < 20kW

I did wonder about the intensity of your response, since I was certainly not trying to belittle or ridicule anybody. That is just not the way I am

MisterBill2 if it makes any difference I didn't think u were ridiculing me. I just thought you missed point of my post cuz of skimming w/o actually reading it, so anyhow your next post proved I was wrong! So totally embarrassing part is I was guilty of exactly what I wrongly accused you of by not reading further on thread b4 drawing conclusions

 

MisterBill2 that's what's perfect abt resonant pwr osc for work coil driver (like _Mazilli Royer_ which is sometimes WRONGLY called ZVS) cuz it's totally self matching and _optimal freq seeking_! So o/c other topologies work too including _freq tracking_ SMPS but I say that's impractical for apps < 20kW


MisterBill2 if it makes any difference I didn't think u were ridiculing me. I just thought you missed point of my post cuz of skimming w/o actually reading it, so anyhow your next post proved I was wrong! So totally embarrassing part is I was guilty of exactly what I wrongly accused you of by not reading further on thread b4 drawing conclusions

OK, Aleph, and what sometimes happens at 3AM is that I miss stuff. I lost my infallibility back in 1969 and have been a human ever since. The explanation for that is only avaialble on a need-to-know basis, and nobody needs to know. So we can be friendly from now on.
The closest that I ever came to intentional induction heating was in applying for a job at an induction heating company. I had studied the technology for two days but still they hired somebody else.