Picked the “beasty” up this morning – I wish all eBay transactions were that smooth. It’s a great size for what I need so after no time at all I decided to test it.
The oven is set to the maximum temperature (280ºC) – I won’t be going that high but that’s the setting that I’ll use with the PID controller, when I put that together. Here are a couple more views:
The thermocouple is stuck to a bit of prototyping board with some kapton tape. I’m really glad I waited for an unused oven – it would be pretty horrible using one with stuck on burnt lard all over the place!
I hooked up an Arduino Uno for testing with the thermocouple being connected to an AD595 thermocouple amplifier. There’s a 16×2 LCD display to show what’s happening and the Arduino also logs time and temperature data to the serial port. Here are the results:
I switched the oven off once the temperature reached 250ºC and also opened the door. This all looks ok to me – it’s not bad for a 600W oven, probably due to the small volume and the 2 heating elements that are used. It looks like it will be able to match the typical SMT soldering profile fairly well.
So, I need to bung in a solid-state relay, bypass the mechanical timer (if possible, no big deal if I have to still use it) and then use Brett Beauregard’s PID library for Arduino.
So, out come the screwdrivers and over goes the oven…
So, that’s the end of that idea until the security bits I just ordered turn up – Tuesday, allegedy.
I guess I can think about putting the controller circuit together and figuring out some kind of housing for it. The housing part is always the hardest for me, even on rare occasions where I actually have the right tools then I’m still just too ham-fisted to put anything decent together. Wonder what I’ll manage this time 🙁