I built this oven to easily solder SMD components.
As a basis, I use a cheap mini-oven. The built-in heater was too lazy to follow the required heating curve precisely. Therefore, I removed the original heater from the oven and mounted two 1000W halogen tubes. These react very quickly to changes. The downside is that the radiated heat preferably warm dark surfaces (ICs), which is why it is very important that the heating curve is being followed.
As temperature sensor I went for the PT1000, because it is almost linear, provides highly accurate readings and is suitable for the application range 0 - 250 ° C.
I designed the control unit the way, that I can put it to the right side of the oven. This way I have a everything packed into the oven.
The ReflowPower PCB is the part of the control unit hosting the power electronics components for AC. The regulated power output is being controlled with half-wave controller via a triac circuit. This board is rated for 3680 W (16A at 230V~). Most main switches available are rated for maximal current of 10A. So I decided to put a relay on the board as a main switch for the whole device.
This board also has a 5V output for the logic circuit.
The schematic and layout files (including eagle files) can be found in the download section on this page.
The ReflowCtrl is the part of the control unit hosting the logic elements (5V DC). The microcontroller with its I/O-Ports for LEDs and buttons and the UART-Interface to communicate with the computer and the amplifier for the signal of the temperature sensor are on this board. Those components need the 5V DC power supply of the ReflowPower board.
The schematic and layout files (including eagle files) can be found in the download section on this page.