A reflow oven I built during my Sophmore summer as an Undergraduate at Virginia Tech to surface mount SMD components onto PCBs. The oven uses a solid-state relay to regulate the temperature of the oven and fiberglass insulation to reduce the thermal loss. The whole system is controlled by an STM32F103C8 development board controlling the solid-state relays duty cycle via pulse-width-modulation allowing the system to follow a reflow profile. The heating elements were wired in a 2P2S configuration and I set a hard cap for the solid-state relay at around a 40% duty cycle – this could probably be raised to increase performance, but a 30% duty cycle met my needs and didn't melt the housing of the oven.