Ben Heck's Home-Brew Solder Reflow Oven 2.0

Ben's fed-up with the difficulty of soldering surface-mount components by hand and builds a new reflow oven to keep in his shop. He transforms an inexpensive toaster over into a vital tool for electronics engineers and tinkerers. In this updated oven, he uses two thermal couples to ensure even heat distribution and effective reflow.

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[googlemac]

You might want to check the Thermistor circuit - the analogue sensor will always see Vcc. (I am glad to see that others can leave stuff out as well!)

[rdoetjes]

Very good tip about checking connectivity with heatsink. In tech-college during the first semester, we had to make a 240V dimmer using a triac.
When I went to get it approved, by the teacher he was like, looks great just push the triac down on the circuit board and screw it down. So I pushed it back and got a massive jolt.

My teacher looked at me as if I was a typical Hollywood actor faking it. I was like: "FUCK ME! THAT'S THE 220V!" He was like: "No way!!! If it's even on the 'hot bed' than it's on the low voltage end 12V. So I said: "Well you try it, sir!"

He said: "Do I look that stupid to you? I have the DIGITAL" (which was The Dutch component bible off the early 90s -- ironic for a typical analogue part).
He looked it up and was amazed to see that the heatsink was indeed the AC, ground (for AC it makes no difference). He made in in the spur of the moment lesson out of it. Pretty cool to be in the 5th or 6th week of your college and learn this shit the hard way. I guess that's what college is all about, learning by doing it.

[Mbts]

finally, project that only took 1 episode. its much better than having it split. i like it

[InsaneWayne]

Another really good video Ben. I particularly like the tips about proper troubleshooting, and going in reverse with one piece at a time. It sounds obvious to people who have experience with troubleshooting issues with code, circuitry, etc.; but people new to this type of stuff probably won't automatically think about it that way. Good job.

[frollard]

Something to keep in mind about that thermocouple - the temperature 'read' by the chip is the difference between the thermocouple itself and the reference built into that chip - so 'inside' the oven control area the chip might get warm which means your oven will read higher than it is - A good idea to check and make sure once the oven is hot use a thermocouple on a multimeter and verify the readings are still good.

[SirDizarm]

Thanks for the thermistor and thermocouple introduction this was just what i was needing! Thanks a million! 

[herctrap]

you are missing a resistor in the thermistor schemmatic

[robotronix-co-il]

in the thermistor you should have a resistor beforethe ptc /ntc else you will always get vcc

[tubeDude]

1) Dim control is actually Contrast control.
2) Using header is a very good idea.

[NathanGoodfellow]

This is on my todo project list!  Thanks Ben!

[tubeDude]

Ben, how about some links for the various modules for this project.
And more detail on how they are exactly connected.
--
Example: Thermal Couples & controllers. Brand and/or part # - Power Supply, etc.
Also the LCD and its controller.
--
And the Code would be nice!

[tcarney]

Another great show! Thanks! I might add, though, that I think you can get rid of the constant background music.

[mac]

Is the white board drawing of the thermistor right ... the analog sensor signal is connected directly to Vcc ... just asking ... ???

[bluerobin]

Very, very nicely done video. I really enjoyed it.

[brandonetheredge]

What did you base the reflow code off of? Or did you write the whole thing from scratch?

[Neslekkim]

instead of using two thermocouple amplifiers, and since you can read only one at the time anyway, would it be feasible to add some switch to select which of the thermocouples to read instead?, and use only one amplifier?
Or is there some requirements around the amplifier and thermocouple that it should be connected the whole time?

[crosses]

Is there a list of all the components I would need to do this build and the code for the embedded chip? Is there a step by step guide to build these? Also any toaster recommendations?

[vehasmaa]

Wish they would sell those toasters in my country. Sadly haven't found any in consumer stores...

[peterbabb]

Ben where can I get the code you used and plans for the Ben Heck's Home-Brew Solder Reflow Oven 2.0.

[tetsujin_]

So, about this thing...
The solid state relay is mounted to the wooden panel - which means practically no heat conduction away from the SSR. Is this a problem in practice? I've been gearing up to build my own reflow toaster, and one of the things that's concerned me is that all the documentation on the SSRs (plus several angry reviews) seem to indicate they dissipate some of the switched power as heat, and therefore need to either be seriously de-rated (like using a 50W SSR to control a 10W load) or else stuck on a big heatsink to dissipate that heat. With that in mind I went with a higher current rating on my SSR than I really needed when ordering parts...  How important are these concerns in practice, given that a reflow toaster like this will only be operating for a few minutes at a time, etc.?
Also, what kind of heat-up/cool-down rate did you get from this oven? Was it fast enough to fit the profile?
(And isn't it kind of irritating to have the controls and display on the side of the oven instead of the front?)