Hacking the IKEA 2kW induction stove (updated August 13th with part 2)

[madsbarnkob]

I started up on a series of youtube videos, website articles and forum threads about hacking this Ikea product into something more useful.

All condensed information on my website: http://kaizerpowerelectronics.dk/general-electronics/hacking-ikea-2kw-induction-hob/
highvoltageforum.net thread: https://highvoltageforum.net/index.php?topic=104.0

youtube part 1 of 5:



The controller is a HIGHWAY09A. The brand name on boards and components are HIGHWAY, which is from the Chinese company Guangdong Highway Electronic Technology Co., Ltd. http://highway-global.com/

In the following table is the manufacturers own “datasheet” for the MCU found in the IKEA induction hob. Click the model number for their own page, I also corrected the spelling errors and I think it is worth mentioning that they advertise their product specifically as Imported chip with stable performance.

Model: HIGHWAY09A http://highway-global.com/product/html/?116.html
1. 16DIP package, OTP type chip
2. 16 pins with single-chip touch. Apply for all induction cookers.
3. Imported chip with stable performance
4. Program Memory:4K x16
5. Data Memory:160 x 8
6. Up to 4channels 12-bit resolution A/D converter
7. Program can not be erased and not be re-written

A few searches quickly gave me the idea that Holtek could be the true manufacturer of the microcontroller, as these are used extensively in products from China and the above specifications also pointed me in that direction.

I have spent hours browsing through the product catalogues of Holtek Semiconductor Inc. ( http://www.holtek.com.tw/ ) and the closest I ever got to find a microcontroller with all the above specifications was the HT46R51A ( http://www.holtek.com.tw/documents/10179/116711/46r51_52av130.pdf ), but the pinout does not match 100%, but very close, so far my conclusion on this IC is that its a older product or simply a custom pinout IC made specifically for Highway.

So if anyone can recognize that pinout or something like that, it would help me get closer to look at the software, if thats possible.

[mariush]

I had to fix one of these for my parents.

After a while the fan gets dirty with oils / grease / whatever same for the plastic mesh over the fan so basically the insides overheat.
On my unit the IGBT blew up after maybe 6-10 months of use and when it died it took out the viper chip with it, the offline switcher IC which produces 18v and 12v
My unit needed 18v for the custom fan and to drive the igbt and 12v for the led digits  and comparators/opamp and everything else.. and it used a 5v regulator for micro

I couldn't get it working after replacing the viper chip,something else died in the switching psu, so i just removed the tiny transformer and got a separate 30v psu board from a broken inkjet printer and then used two linear regulators to produce the required 18v and 12v. Wasted too much time waiting days to receive the replacement viper chip from other countries and didn't feel like wasting more time with it.

Really, they should just use a 15-18v AC toroidal transformer inside and a couple linear regulators and be done with it... but i guess they need the low stand-by power
So much circuit board wasted with the offline switcher when the product itself uses so much power when in use that the stand by inefficiency wouldn't matter
 

[madsbarnkob]

They chose the offline low voltage step down ICs because they are much cheaper than transformers and a transformer will also add to shipping weight, so its only a matter of keeping costs down. Even with efficiency requirements, they would find a way to use a transformer if it was cheaper

[DBecker]

Really, they should just use a 15-18v AC toroidal transformer inside and a couple linear regulators and be done with it... but i guess they need the low stand-by power
So much circuit board wasted with the offline switcher when the product itself uses so much power when in use that the stand by inefficiency wouldn't matter

I don't know anything about the low-end market, but it's obvious that single-side circuit boards are so cheap that optimizing the area doesn't matter even when they are shaving fractions of a cent elsewhere.

A heavy transformer, on the other hand, costs money everywhere, from designing physical support to stronger boxes for shipping.

Energy Star (and similar) requirements might seem absurd for a high-wattage heating appliance, but they aren't.  This appliance may well be left plugged in continuously.  A power transformer will waste significantly more power over it's life than it costs to do better.  It doesn't matter if it's in a 2KW appliance, or a clock.  A typical consumer has no hope of comparing true operational costs,

[madsbarnkob]

Hacking the IKEA 2kW induction stove, measurements (part 2)

All condensed information on my website: http://kaizerpowerelectronics.dk/general-electronics/hacking-ikea-2kw-induction-hob/
highvoltageforum.net thread: https://highvoltageforum.net/index.php?topic=104.0

youtube part 2 of 5:


Quasi-resonant inverter topology
The output power of the inverter can be controlled by a Pulse Frequency Modulation (PFM) with fixed off-time and variable on-time. The waveform of the resonant voltage changes whenever DC-LINK becomes LOW or there is any change in load impedance. The amplitude of DC-LINK (VDC) ranges from zero to maximum as the capacitor has a small capacity.

When observing the waveforms of the current and voltage in the resonant circuit, it can at first be very confusing as the measured amplitude seems to follow the trigger level, so it is actually easy to lock on to a stable signal, but that does not tell the whole story. With the horizontal time base at 10 us/div where the single switching can be observed, it is impossible to discover what the waveform actually looks like at 2 ms/div horizontal time base, here it can be seen that all power is drawn within the full-wave rectified mains 100 Hz envelope.

Pulse Frequency Modulation
Divided by the red line we have power mode 5 at the bottom and power mode 9 at the top.
It can be observed that the off-time of the purple gate drive signal is identical in both power modes, so this pulse frequency modulator operates with fixed off time.
In quasi-resonant switching, the device does not have a fixed switching frequency, which is also clear from looking at the two waveforms, due to the longer on-time at high power, the resonant frequency is lower. The microcontroller waits for one of the negative half-cycles in the collector voltage and then switches the IGBT on.

The time between IGBT turn-off and the first negative half-cycle is fixed by the resonant frequency. The time between IGBT turn-on and turn-off is set by the microcontroller.
The narrow frequency span from 22 to 25 kHz does not pose any significant problems in designing the magnetic components, but it is enough to get the resonant current to rise up the maximum power level that can be drawn from a regular mains outlet.

[taemun]

@madsbarnkob:
What happened to this project?

[GigaJoe]

It was cooked ... 

[madsbarnkob]

@madsbarnkob:
What happened to this project?

Life happened

I bought a house, moved my work shop and lab, had to do some repairs on the house etc, 2 kids, living in the fast lane, I will eventually get there  I made some videos about moving https://www.youtube.com/playlist?list=PLw4xMO1xCMSX0FJ2yfI_hAlKlWi6Lx6zG

I know exactly where the project is, its on top of my drill press. So it is not forgotten, it is just in a long queue of many interesting things I want to deal with

[taemun]

Haha, happens to the best of us.

If you end up with an abundance of spare time, I think this was an interesting project!

[TurboTom]

Convert it into the world's fastest QI charger? 

[iWei]

https://pons.blog.jp/archives/72625937.html

Although its in japanese, google translate works well

He managed to program a microcontroller(with Configurable Logic Cell that does the heavy lifting) from scratch, making a very simple induction heater based on the same topology albeit with absolutely 0 protection