Electronics > Projects, Designs, and Technical Stuff

ZVS Induction heater 2000W 40A 50V

<< < (5/7) > >>

CopperCone:
I wanted to build one with h bridge phase power control. This way you could use a dspic to control both phase and frequency.

This seems less parts heavy then designing a high power adjustable supply for the circuit in this thread. The only benefit i see is that it operates at the resonant frequency without tuning, but it seems to have a potential startup problem.

Is there any benefit to using dual stages vs full h bridge control with an adjustable induction heater.

However as your melt gets hot the inductance changes so the resonance frequency changes and you get power loss... So this method may be better then phase control for that reason.

I guess that you would need to add a pll tracking circuit to the mcu and have the mcu periodically sample the pll output to adjust the center frequency..

T3sl4co1l:
Back in industry, I used a single stage, full wave, frequency offset control.  Simplest power stage, but crappy to compensate.  Wanted to try phase control, but the driver and output stage didn't have the logic to support it.  Yes, you need a PLL to track resonance, or something near it in any case.  Phase shift PWM gives you effectively a variable voltage source, exactly what you need.  With the system at resonance, the amplitude response is a (single or repeated?) pole at the tank time constant, low Q and easy to compensate.

Downside is 100% switching loss and EMI.  A tri-level inverter (a half bridge with a shorting-to-zero mode) might be preferable for this reason.

Tim

j2000:
Hey Strawberry...thanks for the schematic...
Did u sell DIY kit complete?

Regards
Joel

IvanLazarov:
Hi Strawberry, thanks for sharing the schematics for your induction heater. I will try to build it myself.

Can you please advice what should be the current rating of chokes L1 and L2? If the total power is 2KW, does that mean that each choke should be rated at minimum of 20A?

What is the purpose of the additional circuit on the right hand side that you included in the latest revision the drawing?

Cheers,
Ivan

strawberry:
1/If you want do serious staff with it, then L1 L2 will be redesigned.
2/It is protection circuit idea

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod