IGBT Driver – Out With The Old, In With The New (Year)

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IGBT Driver PCB

First off, happy New Year! I hope that everyone is doing well in 2018. The first batch of¬†IGBT Driver boards (Hybrid Driver v1.3) from PCBWay came in today, and they look great! ūüôā

IGBT Driver Old And New - PCBWay

PCBWay Manufacturer

This¬†order was my first time using PCBWay¬†and I am blown away by how seamless from end to end the entire process is! I love the technological process tracking, it’s funny, but it reminds me a bit of how some pizza places track the progress of your pizza. My order was accepted, manufactured, shipped and in my shop in no time at all!

The quality of the boards, through-hole plating, silkscreen, bottom side tinning, and everything is a definite A+. I received excellent communication and engineering cooperation from the beginning. Although there are other PCB manufacturers that I like, I am going to use these guys going forward!¬†I’d recommend¬†them for prototyping or production.

PCBWay Technological Process Tracking

Open Source Advocate

I especially like that they encourage open source projects by allowing you to share your board designs, schematics, and project details after ordering. Here is the Hybrid Driver v1.3 in PCBWay’s project sharing section. ¬†They make it easy for others to order¬†boards since all the Gerber files are already there and pre-approved. They even give a 10% back to the project creator. Check it out and take a look at there projects, there are some impressive ones. I like OpenReflow, a control board to convert a simple toaster oven into an accurate¬†reflow oven for soldering SMD components.

IGBT Driver

The new driver boards look great. I like the high gloss black solder mask and the highly visible white silkscreen over it. The slots for the IGBT gate connections turned out great. The board edges are clean and completely burr free.¬†The only mistake I’ve found is that I forgot to set the OSH logo font to vector, so it expanded a bit and overlapped the G2 silkscreen. I also tweaked a few device¬†name¬†silkscreen¬†positions to improve visibility.

IGBT Hybrid Driver v1.3

I’m waiting for the bulk orders of the¬†VLA106-15242 isolated DC to DC converters and the M57962L gate drivers. After that, I’ll stuff the boards and get them in the ReactorForge to continue refining the firmware.


IGBT Driver Stuff Board

The First Kit

I’m planning on making the IGBT Driver (Hybrid Driver v1.3) the first complete kit. Of course, it will be standalone, apart from the rest of the induction heater. I’m ok with having the major components of the induction heater available individually as well as part of the whole machine kit.

I have never made a kit like this, but I am entirely confident¬†that I can put together a great one. Still, this will give me the chance to test that confidence on a smaller scale. I’ve already established a supply¬†chain for the parts and the PCB. What’s left is ordering consumables such as antistatic shielding bags, labels, and packaging. Then,¬†of course, the written¬†plans or instructions for the kit.

ReactorForge History – A brief history lesson 01010010

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ReactorForge History

There were many before it, after it and in-betweens, but these are the milestones! This is a brief ReactorForge History lesson.

ReactorForge History

From left to right.

  • The first MOSFET version on a PCB. It worked great but didn’t couldn’t handle the power level I wanted. I ended up pushing it to failure and moving to brick IGBTs.
  • The first IGBT version on a PCB. This design is based on a CD4046 PLL and uses gate drive transformer to drive the large brick IGBTs (the ReactorForge now uses hybrid drivers). If you are into electronics and you’ve never worked with a PLL, even if just on a breadboard you should. PLL’s are very well documented, fascinating little devices. This circuit works great but its frequency operation range was limited by the external passives for the VCO (voltage controlled oscillator). Due to its reliance on these passive components, it is also affected by temperature.
  • For mainly that and a few other reasons I decided to explore a software PLL solution. After going around the usual suspects and understanding how a PLL worked I thought there must be some way to do it with a low-cost MCU, not a freaking FPGA or high power processor. Maybe some type of PWM/comparator combination I thought. I found my solution in a motor controller, or power stage controller chip made by Atmel, the PSC216,316 microcontroller. That’s what this breadboard is, the early testing for what is now a rock-solid way to find the resonant frequency (Fr) and adjust power levels by offsetting that frequency from the current Fr all while soft switching (i.e. not making heat in the wrong places and exploding electronics). This was the result of those early tests…

ReactorForge History - Current

The Future:

One more board redesign may be in order but we’ll see. I may look into reducing the size of the board down the standard Eurocard PCB size of 100mm x 160mm. Although the current size is still within the free size limit of 160mm^2 for Autodesk Eagle.

That was the¬†ReactorForge History, now let’s forge ahead to the future!