I haven’t shared anything for quite a while. While going through my archive, I came across the 8 Channel 24A triac animation card that I had prepared six months ago. Clearly, I had forgotten about it. After a brief review of the project files, I decided to share it with you.
I originally designed this card for use in an amusement park, and so far, there have been no complaints about its performance. It has been functioning smoothly without any issues.
In this circuit, I utilized the BTA24 600BW triac, which, according to the Triac data catalog, can handle up to 25A and 600V. I employed the MOC3020 Triac driver with an optical isolator to drive the triacs. The processor used in this setup is the Pic16F628A.
Initially, the animation variety was limited due to specific requests. However, today, I updated the software and added a few more animations, which made the system more satisfying.
The circuit diagram is as follows.
Follow the given link in the below for high resolutions pictures.
There was a lot of load on my circuit. Of course, max. I measured the current. Approximately 7-8A per channel was drawn. As a result of this current BTA 24 were slightly warmed. It wasn’t excessive heat. I didn’t care.
The PCB is as follows:
The BTA24 triacs have an isolated A2 leg and body, allowing for single refrigerant connection without interference. Always apply heat conduction pastes when connecting to the cooler. Alternatively, the BTB24 can be used as a triac, but note that its A2 leg and body are connected. Hence, you must isolate the triacs from the cooler when connecting to a single refrigerant to avoid suboptimal performance. Additionally, on the PCB, especially in the load section, ensure that the high-current paths are thickened with a substantial solder layer. Otherwise, the copper traces might evaporate under high current alone.
While BTA24 triacs tend to be pricier, if you don’t require significant current, you can opt for triacs like BTA16 or BTA12. The connection legs are the same for these alternatives.
Let me give you the pictures of the circuit.
Finally, let me tell you this. Where do you always have the PCB on the circuit? They ask. I’m telling you how I do. The simple fact is that it almost goes through the same stages of printing the subprint.
I do this;
Essentially, it’s akin to creating double-decker PCBs. Initially, I press the bottom of the PCB and remove it from the acid using an iron. Then, I drill holes in the corners or appropriate parts of the PCB. For example, using 3mm holes in the corners facilitates easy installation. I don’t recommend punching holes before pressing the material.
Since the lower copper is perforated from the surface, it forms burrs where components will be placed. Even tiny burrs can cause issues when printing the component surface. So, I only create 4 alignment holes in the corners of the PCB, ensuring I clean these burrs thoroughly.
Next, I print the mirrored element on paper once more. The following steps remain consistent. I place the printout from the printer on the opposite side of the PCB. After aligning it carefully with the holes, I secure it in place, ensuring the paper doesn’t move from the sides and corners. Correct alignment here is crucial; any error can affect the outcome significantly. Attention to this detail is paramount.
Subsequently, the ironing process follows. I use medium heat and iron it for about 4-5 minutes. Once the ironing is done, I let the paper and PCB cool slightly. As the paper softens, it naturally separates from the toner, which adheres to the PCB. If you leave the PCB to dry completely, you’ll notice a white residue due to the paper sticking to the toner. To resolve this, it’s crucial to dry the PCB thoroughly and use a toothbrush without adding perhydrol to gently remove any remaining paper residue while immersed in the acid. The acid effectively dissolves the paper particles. After ensuring everything appears black, wash the PCB with water. Not letting the PCB dry completely will prevent bleaching due to paper residue.
It’s essential to consider the specific requirements of the PCB you’re working on. For some projects, overprinting might not be necessary, while for others, visual appeal might be just as vital as functionality.
By following these steps closely, the PCBs you create will be ready for use.
I’m gonna say that for now. My archive cleaning work is in progress. Soon, I will always come up with the projects I have done on the foot again.