With a lot of people who are suddenly too cool for through hole and of course the a few generations of components that are only available in SMD packages, it’s no surprise the humble toaster oven has become one of the mainstays of electronic prototyping. You’re gonna need a controller to ramp up those temperatures, so here are two that do the job quite nicely.
[Nathan]’s Zallus Oven Controller is a bit different than other reflow controllers we’ve seen on Kickstarter. He’s offering three versions, two with different sized touch screen displays, and one that is controlled with a PC and push buttons. The display for these is beautiful, and of course you can program your own temperature profiles.
If Kickstarter isn’t your thing, [Dirk] created his own reflow controller. Like the Zallus, this has a graphical display, but its homebrew lineage means it should be simpler to maintain. It uses a K-type thermocouple, and unlike every other reflow controller we’ve ever seen, [Dirk] is actually checking the accuracy of his temperature probe.
No, reflow oven controllers aren’t new, and they aren’t very exciting. They are, however, tools to build much cooler stuff, and a great addition to any lab.
“and of course the a few generations of components that are only available in”
the a?
You can get thermal couple signal conditioning+ ADC all in a chip with the familiar serial digital output. You can even get them prebuilt on a PCB if you don’t mind the mark up. This now eliminate the off chips source of error and the accuracy is now guaranteed by the datasheet as long as you follow all the instructions and environmental conditions that it is designed for.
That should save the calibration step as long as you are happy with the accuracy from the factory. To get more accurate results, then you do the calibration. This application, even a couple of degrees off is okay as where you are measuring on the PCB can be make more a difference.
those modules are often more expensive than WHOLE multimeter with thermocouple and serial output
I use an AD7792. It’s got 3 channels. I use one for the thermocouple, one for an NTC. It also has very nice 50/60Hz filters. With a few external caps you can get very stable measurements. Less than $10 for the entire circuit.
If I had known toaster oven reflow controllers were worthy of mention here, I would have sent in a mention of “Toast-R-Reflow” – which is my take on the genre. Unlike most folks, I went with opto-isolated triacs instead of SSRs, and made a separate power switching board that I built into the oven for maximum safety. The wire that exits the oven is effectively just the LEDs in the opto-isolators. It goes to a 2×16 char LCD “backpack” board that has an ATTiny84, an AD8495 and a 1.8 volt LDO (used as an A/D reference to increase the temperature resolution. I’ve been using this solution for over a year now and sell the two parts in my Tindie store.
Hmmm. I have one of these SSR’s here. If I pulled it apart I would expect to find an opto isolator and triac and resistor for the LED.
I prefer the SSR’s as they keep mains voltage out of reach.
I’m in the middle of a similar build, but I’m getting sidetracked so I backed the Zallus. The Zallus has the SSR separate should also be possible to set it up in this manner too.
Toast-R-Reflow PCB in different versions are available! ?
these are fun projects but always overkill. i’ve been using a panasonic ir toaster to reflow for years with no problems. just turn on full power, wait for it to reflow, count to 10, then open door and turn off. zero failures in 50+ boards including .5mm spaced BGA components, etc.
Please report power, heating elements and distance and model if available.
I recently could not get paste to reflow before blowing a capacitor and browning the board (1st attempt).
How many balls on the BGA part ?
ControLeo2 Reflow oven is now up on Kickstarter
http://www.reflowcontroller.com calibrated with a NIST certified instrument and cheaper than the others !! sourcecode too and a great GUI with many many features that the others :-)