With the heating elements working correctly, we moved to the next step, which is to connect the fan into the system as well. The fan will be connected to the microcontroller through another SSR. It will be powered using the line power from the wall. Optimally, we want the fan to always turn on during the whole reflow process. Below is the picture of the new system after the fan is connected in: With the fan always turned on at 100%, we did the...

Today we looked up for the surface mount components that we are going to use for the testing of the oven. These components will be placed on top of a board. By spreading the solder paste (Sn63Pb37) on the board with the components and put them inside the oven, we’ll be able to see the oven’s performance and if it meets our requirements or not. Some basic surface mount components that we need are: – The 8051 micro-controller:...

Knowing that the oven’s current state would not be efficient enough for the complete reflow soldering process, we decided to figure ways to improve its overall performance. One big reason behind why it’s not really efficient enough is because even though the oven has 4 heating elements in total, its internal capacity is too big and thus it takes longer time for the oven to heat up. Therefore, by placing some large bricks into the...

We figured that the reason why the oven’s not working at 100% is due to the diode. As we explained earlier, before the power going to the heating elements it has to go through the diode which converts the AC power into DC. Using the digital multimeter, we measured that the voltage before the diode is around 117V, but after passing through the diode it drops down to only 64V. Therefore, we conclude that the diode is the main reason why the...

Today I made some basic studies about the quartz heating element that is used for our oven. The quartz electric heating elements provide medium-wave infrared energy with a fast heat up and cool down time. With element temperatures ranging from 1000 °F (537°C)  up to 2000°F (1093°C)  the elements produce infrared energy in the 2 to 3.5 micron range. Lower operating temperatures produce longer wave lengths. Quartz Infrared offers...

As we mentioned earlier, the original oven circuitry has the two upper elements connected parallel with the two lower elements. After doing some rewiring, by disconnecting all the controllers from the circuit and adding the micro-controller in, we got a circuit that look as following: There are many different ways that we can connect these heating elements together and therefore we figure that before we do any more rewiring, we should do some...