I'm new to this community and in electronics world at all. I'm happy to announce that I'm about to begin my first project ever and I would like to read your suggestions and additions to my so far research on that topic.
Let me first describe in few lines the idea of that project. All in all is that I want to heat and cool a small volume of solution around 100 to 500 microliters. Since I'm coming from a web developing background, I was though to use raspberry pi zero W, in order to create an AP (access point) which will serve a specific web page where a user will set something like that:
So as I already mentioned, I chose as the main platform for that project the raspberry pi zero W. Further, I broke down the whole project into smaller pieces.
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1 - Ramp up to 65 C and stay @ 65 for 20 min 2 - Ramp up to 95 C stay @ 95 C for 10 min 3 - Ramp down to 20 C and stop
A. HEATING STAGE
For that stage, I conclude on two different approaches.
1) Peltier element.
While searching online for a Peltier that can reach out the temps that I want, I found these two [ 1, 2 ]. Peltier is a good idea because it gives you the chance to use it for cooling too. For this to happen polarity should be changed and thus an H-bridge is needed. I found this one on eBay and it seems really widely used.
2) Heating element.
This is another way to heat up the solution. I'm not sure if this approach makes sense or not and it good to be "judged" from you. So far I found this heating element on eBay too but I really don't know if this is going to work for me. Any ideas here are welcome.
B. COOLING STAGE
Independently of using Peltier for cooling or not, I take the existence of a fan for granted.
As you can imagine, in order to keep the temperatures as stable as possible I'm going to need a temperature sensor like this or that one.
D. POWER SUPPLY
This is the last sub-problem that I figured out. The whole project I would like to be powered from only one socket/cable and not more but as you can see, for example, the Peltier elements, want about 15.5-15.7 V to work out while at the same time raspberry pi zero W wants 5V. So which is the best approach for achieving something like this? Are there any module/boards that have one power input and can split voltages into different values? How did they call?
As I already mentioned, this is my first ever project. I have a programming background but not that much in electronics. So If you think that all the above are totally wrong or that I have some mistakes/missing elements etc. please enlighten me with your knowledge. I would very thankful. Of course, if you believe that I need to change some elements please also let me know.
P.S In your answers, act like there is no budget problem.