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Looking for an electronic geek

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  1. #1

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    Looking for an electronic geek

    I am looking for someone who can help me to design a PWM controlled (Arduino) step down buck converter.
    It is not for business, so it would be nice not to cost me an arm and a leg.


  2. #2

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    Try sticking up a notice in the Elec/Comp Engineering departments at one of the universities. This is the kind of thing that 2nd and 3rd year students do. And it should be cheap.


  3. #3

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    Curiosity question : What will you use it for?
    I had no idea what it was so I googled it - now that I know what it is, I'd like to understand its real world application...


  4. #4

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    Quote Originally Posted by HowardCoombs:
    Curiosity question : What will you use it for?
    I had no idea what it was so I googled it - now that I know what it is, I'd like to understand its real world application...
    Efficient temperature control with a peltier element. Driving the voltage down is better than frequent on/offs. I do home baking and like to play with microcontrollers. So I design a temperature control for sourdough fermentaion. Everything is running smoothly already except the fact that the PWM signal is probably not good for the peltier.
    That buck converter would also be useful to control motor speeds or LED brightness..
    Last edited by hktraveller; 19-06-2014 at 10:25 AM.
    HowardCoombs, jgl and Rob2020 like this.

  5. #5

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    Quote Originally Posted by jgl:
    Try sticking up a notice in the Elec/Comp Engineering departments at one of the universities. This is the kind of thing that 2nd and 3rd year students do. And it should be cheap.
    Thanks a lot. Will do. The components are cheap and I am able to build it myself. I just can't calculate the inductor and capacitors as I always learn by doing but for this I don't want to spend ages reading. Probably much faster if someone with knowledge explains it.
    Last edited by hktraveller; 19-06-2014 at 10:30 AM.

  6. #6

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    Quote Originally Posted by hktraveller:
    Efficient temperature control with a peltier element. Driving the voltage down is better than frequent on/offs. I do home baking and like to play with microcontrollers. So I design a temperature control for sourdough fermentaion. Everything is running smoothly already except the fact that the PWM signal is probably not good for the peltier.
    That buck converter would also be useful to control motor speeds or LED brightness..
    Fabulously geeky!

    I've recently spoken to a student who's project included using a PWM controller to controller an electric motor, hence the university notice board suggestion.

    Note however that most of them are now on summer break so it might take a while to get a reply.

  7. #7

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    Quote Originally Posted by jgl:
    Fabulously geeky!

    I've recently spoken to a student who's project included using a PWM controller to controller an electric motor, hence the university notice board suggestion.

    Note however that most of them are now on summer break so it might take a while to get a reply.
    I am not all that urgent because you could probably guess that I am alredy working on this for quite a while (Even have bluetooth implemented).
    All the bucks on the market are pwm controlled. My problem is that I want to control the pwm on/off times in response of sensor readings. For that I use the Arduino which comes cheap and has many accessories and shields available, but unfortunately not this one.
    As I need about 10, I will make a pcb for it and probably offer a DIY set to the Arduino community.

  8. #8

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    @hktraveller How's your project going? Have you posted details of it online?


  9. #9

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    Quote Originally Posted by Rob2020:
    @hktraveller How's your project going? Have you posted details of it online?
    I am just now building the final version of 5 prototypes. Managed to solve it by myself which I am proud of. Of course I could have gotten it faster by asking someone.
    I found a reasonable dc/dc step down buck converter capable of 5A and managed to replace the manual potentiometer by a digital one. Because the digital poti allows only 5V at the wiper, I use small relays to switch resistors between as soon as the voltage gets higher.
    I was lucky to find the factory of the buck converter and they are willing to get me a few without the poti soldered on which saves me the desoldering.
    I will post a link to youtube as soon as it all works, as I still need to fine tune the program also.
    I believe to have it ready within 2 months.

    The project: A temperature control for heating and cooling with no more than 12V 5A.
    3 temperature sensors possible (One at the heating plate, one inside the controlled aerea and one for the ambient temperature), output current can be regulated electronically from 1.34V to 12V and switched on and off. An encoder and a push button for settings that are saved in the eProm.
    A bluetooth device sends the reading results to a serial port wireless.

    Alternatively I could have used a motor to drive the multi-turn poti, but I try to avoid mechanical parts where possible.
    Rob2020 and 100LL like this.

  10. #10

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    What is it heating or cooling?


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