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Topic: Programmable load (Read 15318 times) previous topic - next topic

Programmable load

Lots of interest in this at Maker Faire. Going to take it up, but something simple without the power/current supply.
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Re: Programmable load

Reply #1
i have a drawing of one i started not too long ago.

feel free to use as you see fit

Re: Programmable load

Reply #2
I am one of those people who was interested at Maker Faire. What I want to make is an Ardunio compatible programmable load that can be used to test battery capacity, power supply specifications, and I/O drive capability.

I am new to this site so I was wondering if you could explain how project are generally fun.

Thanks,

Re: Programmable load

Reply #3
have you seen the project (based on 8051) on itead .. I have one and it works great. Firmware is piece of shit but is open source so if anyone is experienced with '51 could make it better. (would be super simple to make battery capacity measurement device etc... ) they are also working on new version "overload" that looks interesting too

Re: Programmable load

Reply #4
[quote author="arhi"]have you seen the project (based on 8051) on itead .. I have one and it works great. Firmware is piece of shit but is open source so if anyone is experienced with '51 could make it better. (would be super simple to make battery capacity measurement device etc... ) they are also working on new version "overload" that looks interesting too[/quote]

i have access to the silabs debugger, this could be modified for our use.

silabs micros tend to be a little more expensive than the pics, but their base models run at 20mips and up.

i am very familiar with the pca routines that are used. i would upgrade to one with more than an 8 bit adc.

the crossbar feature is as good as the remapable pins in the pic24

Re: Programmable load

Reply #5
well I have the original dummy load and I can say it works pretty nice .. I didn't even tried to look at the source as I don't have with what to compile/burn to mcu ..

I will also order the overload, they will release source and schematic on 1st june but it is based on ATMega328 and with Arduino bootloader (and firmware is arduino sketch) so it should be super easy to modify ... They bumped it up so they can push 3A 12V .. I assume that 12bit adc is internal one on atmega but maybe they used external one too .. They are using 10W 1R resistor there .. I used those a lot for some projects, if you add cooler to them they can push waaaaaaaaaay much current then 3A if you need them to :)

Anyhow with these two products out there (especially is overload show as good as I hope) making another project that does the same is imho waste of resources (and iirc overload is not only programmable load but also current source, voltage regulator, signal generator etc etc) ... I think it would be better to finish up the pc controlled psu that we started while back :)

Re: Programmable load

Reply #6
@ahri - those loads are really cool!
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Re: Programmable load

Reply #7
i will order overload when it is available (they say on 1st) and post back the info here ... the dummy load works ok but is fairly limited (biggest limit is that I really hate 8051 :D and have not used it since 1993)

Re: Programmable load

Reply #8
@arhi Cool stuff. I am interested to hear what the testing turns up.

Re: Programmable load

Reply #9
How about using Dave's idea and replacing the 50k potentiometer with something else? Like a PWM signal (which we have to filter) or R-2R ladder DAC.

Re: Programmable load

Reply #10
@arhi I just saw the Overload are in stock. I got one to test as well and I will let everyone how it goes.

Thanks for the pointer


Re: Programmable load

Reply #12
I have no use for it, but i ordered for "just in case" as with everything else i order :P  i'm worse than a woman in a shoestore

Re: Programmable load

Reply #13
[quote author="tempmj"]I have no use for it, but i ordered for "just in case" as with everything else i order :P  i'm worse than a woman in a shoestore[/quote]

:( aren't we all

I needed a programmable load and actually the original dummy load with 8051 does exactly what I need but ordered new one just to see how it works :D

Re: Programmable load

Reply #14
Interesting design, thanks for the link.
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