DIY Adjustable Constant Load (Current & Power)

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About: Awesome Electronics Tutorials, Projects and How To´s

Intro: DIY Adjustable Constant Load (Current & Power)

In this project I will show you how I combined an Arduino Nano, a current sensor, an LCD, a rotary encoder and a couple of other complementary components in order to create an adjustable constant load. It features a constant current and power mode and can handle a maximum of 30V and 20A if your heatsink design can handle it. Let's get started!

Step 1: Watch the Video!

The video gives you all the information you need to make your own adjustable constant load. During the next steps though, I will present you some additional information.

Step 2: Order the Components!

Step 3: Create the Circuit!

Here you can find the schematic as well as pictures of my finished circuit. Feel free to use it as a reference for your own circuit.

Step 4: Upload the Code!

Here you can download the code for the project. Upload it to the Arduino Nano through the Arduino IDE

Also make sure to download/include this library:

https://github.com/fdebrabander/Arduino-LiquidCrys...

Step 5: Finish the Project!

All that is left to do is mounting all the components inside your enclosure.

Step 6: Success!

You did it! You just created your own adjustable constant load!

Feel free to check out my YouTube channel for more awesome projects: http://www.youtube.com/user/greatscottlab

You can also follow me on Facebook, Twitter and Google+ for news about upcoming projects and behind the scenes information:

https://twitter.com/GreatScottLab

https://www.facebook.com/greatscottlab

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    14 Discussions

    0
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    Yonatan24d8men

    Answer 17 days ago

    If you need a large heat sink, look for a stereo player, they tend to have pretty big heat sinks! Also some desktop computer CPU coolers.

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    kpatel18

    25 days ago

    If i use Logic Level MOSFET ? Do i still Need Mosfet Driver ?

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    sk8nfooldavorin.perkovic

    Reply 6 weeks ago

    Yes - Vcc is red and GND is black. That's not what I asked. Where are the binding posts in the schematic?

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    JohnC430

    6 weeks ago

    I have seen several Electronic loads like this one on YTube. one guy has gone up to 100 Amps. This one is actually building an MPPT controller along with the load which I think is very innovative.

    1
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    bsh0544

    Tip 6 weeks ago

    I recommend moving the fuse to be as close to the Vcc input. That way if the fuse ever blows your whole circuit, including the heatsink accessible outside the case, is pulled to ground instead of Vcc.

    There are also products to electrically insulate a TO220 or similar package from its attached heatsink, to help in these sorts of situations. There is a small compromise in thermal conduction but IMO it's worth it to not have a power connection to an external heatsink.

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    davorin.perkovic

    6 weeks ago

    I think, you have to change the code like this:
    ...

    ...

    if (curcurrent < current) {

    OCR1A++;

    }

    else if (curcurrent > current) {

    OCR1A--;

    }

    // else if curcurrent == current)

    // Do nothing !!!!

    ...

    ...

    if (curpower < power) {

    OCR1A++;

    }

    else if (curpower > power){

    OCR1A--;

    }

    // else if curpower == power)

    // Do nothing !!!!

    0
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    sbelectrics

    7 weeks ago

    A nice modern take on a constant current load I built with a 2N3055, a comparator and a potentiometer many years ago. With all that space inside the case and the built-in ventilation slots, wouldn't it have been tidier and safer to put the heat-sink inside? (The heat-sink can reach well over 100'C in operation.)

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    fmarquis

    7 weeks ago

    Love the project and enjoyed the video. I know this is not a coding Instructable but I think a lot of people would benefit from at least some comments in the code. I was mainly interested in the workings of the menus and rotary encoder and I would say it is not intuitive! Keep up with the nice projects!

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    JanvierD

    7 weeks ago

    Is it possible to change the Rotary Encoder to push buttons? If so, can you make a version with push buttons please? Thx !!!!!

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    carlos66ba

    7 weeks ago

    Nice setup. May I suggest the following: add a temperature sensor next to the MOSFET so it can shut it down if it gets too hot (can be read by the arduino easily).