12V induction heater

[ivan_mateo]

Hi everyone,

I am planing to design a induction heater. Input parameter is clear and will be 12V/12A. If I heat a 1 litre water in short timei it will be ok for me. But I not sure about input voltage, is it possible or not. If the input was from AC line, I can figure out. Can anybody give advice about it in terms of topology and related to that?

 

[pranam77]

i guess no need to reinvent the wheel. Ample schematics are available for the same. But 12v @ 12 amps will probably not powerful enough to heat a liter water in short time. I am using the same for experimental purposes. Contains just two coils, two mosfets, two 0.33mfd caps and few other passive components.

 

[dick_freebird]

I don't think you're going to induction-heat plain water.
Maybe its vessel.

You know the power "take" (12V*12A) limit imposed, so
you have an upper bound to performance (assume 100%
inverter, coupling, thermal efficiencies). Then you can do
the thermal figuring of how long to heat 1000g of water
to (100C-ambient).

It'll be a while, and that's just to -begin- boiling.

 

[schmitt trigger]

Assuming 100% efficiency, 144 watt/second are equal to 34.4 gram calories. Per online units converter.

To heat one liter of water (1000 grams) one degree Celsius, it would take 29 seconds.

In reality, when you take into account all electrical and thermal losses, it will be actually over 1 minute. Per each degree Celsius. Not fast, not fast at all.

 

[FvM]

Instead of an induction heater, you can use a regular immersion heater in a thermos bottle to achieve near to 100% efficiency. But as said, 144 watts will heat 1 liter of water rather slowly.

 

[Easy peasy]

take a look at how fast an electric jug / kettle takes to boil 1 liter of water using 230Vac, 10A - 2.3kW - 1 min perhaps ...

you are using 12 * 12 = 144 watts, so you will take 16 times longer to boil 1 liter of water - 16 minutes assuming no losses to air etc ...