Frank Zhao, an electrical engineering student at the University of Waterloo just made this cool Toaster Oven Hacked into a Reflow Soldering Oven project. If you are working on a project that has SMD components in it you will need to select a way to reflow the solder paste, there are lots of DIY methods out there and one popular method includes modifying a toaster oven into a reflow oven. The existing control circuitry of the oven is scrapped and replaced with a complex controller which closely monitors the temperature and performs specific temperature profiles to correctly heat and PCB properly.

“To control the oven’s temperature, I created my own reflow toaster oven controller circuit. This circuit uses an ATmega32U4 microcontroller to monitor the oven’s temperature using a thermocouple and AD595AQ, and then control the oven’s heating element using a solid state relay. The controller features USB logging/debugging, USB bootloading, a graphic LCD display, and 3 buttons. The firmware features tweaking for all settings, manual temperature control, manual heating element control, and automatic temperature profile control (with a nice temperature history graph display). This circuit will plug into a wall outlet, and the oven will plug into this circuit, while the solid state relay basically acts as a switch between the wall outlet and the oven’s heating element. “