It seems like a right of passage for makers that progress to surface mount work: building your own oven (or other appliance) to do reflow soldering.
The design consists of a power board and a controller.
- Each channel of the power switcher is a basic opto-isolated triac circuit
- MOC-3020 opto-isolated driver triac
- BTA-20 power triac.
- Controller monitors oven temperature and controls the heating elements
- Thermocouple measures the temperature of the oven interior
- PID controller makes oven temperature arrive at a setpoint without overshoot, undershoot or instability.
The firmware is availble in this GitHub repo:
nsayer has shared the boards on OSH Park:
This variant uses an ATMega328P controller and a MAX31855 thermocouple amplifier. It’s more expensive than the model I controller, but there’s lots of room for more features in the flash, it has connections for 3 buttons instead of just 1 and an FTDI serial port
Nick’s Tindie store offers the following kits:
- power board
- Model I controller (ATTiny84/AD8495)
- Model II controller (ATMega328P/MAX31855 variant)