Hello guys!! I am currently designing a little voltage regulator but I want it to make it really safe. Recently I burn a 30$ component in a PCB I made and I don't want it to happen again
I have made this out so far:
The
specs that I am looking for are these:
* Short circuit protected
* Reverse voltage protected
* Low heat dissipation from the regulator - See, I was using a 7805 because I need +5V. Since I am using a Kinetis KL25z for my project, it has a Voltage Input from 5v-9v so, I am planning to feed it with +9v using a 7809 and from the Kinetis there is a pin with +5v so I can feed my other componentes with that. I read that the heat comes because the regulator is not efficient, because going from 12v to 5v, there is a (5/12)*100% = 41.67% of efficiency, and the other 58.33% converts to heat. By changing to a 7809, I am getting a better efficiency: 75%, so "only" 25% goes in heat. Well that's what I think. I have not made any practical testing bydoing so.
Correct me if I am wrong! - I was also thinking on adding a
Limiter Resistance in series to the input Voltage of the regulator, so that the consumed watts, lower. So there will be less heat, but I am not sure if that's really OK.
If my system need more current, will my battery be able to give that?
* Solve random functionality by adding Capacitors - I was having some "random functionality" from the XBee S2C Pro when I turned off and on the system. I had to put a 470uF (just random value) Capacitor from V+ and GND, and it kinda solved it (Not the 100% of the times I turned it on it worked). But I know that this is not the best solution.
What is this problem about? Btw, I know that the Capacitors fix the ripples from the battery but I am not sure if this is what causes the problem.
Well, that's all atm, if you guys have any recommendations or see any problem.
Please tell me=)!Have a nice day=)!
P.D. By the way, I was thinking on adding a Zenner Diode of 8.2v more less, to the Vo, so that the Kinetis doesn't risk a lot, but I am not sure how to add it, I put a Resistance in series in the output and the Vz in parallel, is that just fine?