Hello everyone,
I am having trouble understanding how to do certain task. I need to regulate DC power supply based on certain values that a user will manually input. It there any way I can do that with the ``ready´´ power supply or I have to built one on my own? Also, will I be able to do it with Arduino or are there any better mp that can do that the same task? Any help will be appreciated. Thank you.
PWM your max voltage from a normal power supply (say 12V), and feed that into a large cap. (Note: This is a really clumsy way of doing this. You won't get current control.)
Or look around online. I like Mastech power supplies and you can see if they have what you need.
Thank you very much for the reply. However, my question is still unanswered. How do I hook up the variable PS to arduino (or any other mp) in order to regulate the voltage?
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Dependin on what voltages you need??
A used PSU will provide with lots of power at 12V, 5V, 3,3V and all that in minus as well. I love the old PSU for testing stuff and not so bad if you shortcircut it 
Otherwise you can use some analogWrite to some small breakboard controlling voltage, current and PWM.
You could also build something out of some transistors and some resistors and burn of some heat 
No seriusly, what do you have and what do you need??
I hope you will understand my silly and simple answer, i'll really want to help
I guess my question was not clear enough 
I have a DC power supply. I have Arduino DUE. I also have a LCD touchscreen. I want to input pressure readings via touch interface so Arduino can capture those readings and change voltage. The lower voltage we have, less pressure we have (and vice versa). So my main question is how can I use Arduino Due to control Power Supply? I hope that's clearer. Thank you
So my main question is how can I use Arduino Due to control Power Supply?
Well you said:-
I have a DC power supply
So what sort?
Post a link to the it's data sheet or schematic.
Is it designed to be controlled externally?
If not then you have a lot of work to do. I suspect it is beyond your current knowledge but I could be wrong.
here is a ready built one:-
http://www.amazon.com/Precision-1550-Switching-Supply-Charger/dp/B002BXI8PS. It's one of those. But I will definitely take a look at the one you posted. However, I can't find any information about actually controlling PS with Arduino. Is is possible to do?
However, I can't find any information about actually controlling PS with Arduino. Is is possible to do?
It is not a normal thing to do. Hacking the controls is not easy. That is why the programmable ones cost so much.
OK. But in that case how do I tell PS that I need voltage that will correspond to input pressure values? Will any programmable PS be able to get info from pressure transducers and vary voltage based on that?
No that is what the arduino is for, to take a reading, do some math and then send a command to change the output voltage. The power supply is only one component.
Perhaps if you narrowed things down to exactly what voltage
and current range you need it would be easier to build your own.
How much power are we talking about??
If it's not much, it must be able to build one yourself much cheaper...
Something were you take the input value, "convert" it to a PWM signal that is making a potentiometer go up and down, controlling the resistens and the output.
You can surely make a Donald Duck like solution with some moters? But I'm pretty sure I saw that kind of breakboard on Ebay. converting a PWM into power, from a power supply ofcause
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spycatcher2k:
Why not tell us what you are trying to make? I can't tell,is it a pressure to voltage converter, or do you want the voltage to be selected from a touch screen, or give a reading from a pressure transducer?
What I try to is the project that uses MR fluid. It uses digital power supplies to power up electromagnets that will create magnetic field strong enough so the MR fluid will be solidified. This will create a pressure in pipelines that are connected to the the cylinder with actual MR fluid. What I need to do is have an engineer to input values via touchscreen and voltage will be changed according to the desired value. For example, the user input 120 psi -> 12.1 V. I researched and ended up finding h-bridge with PWM solution. Due to the fact that load (electromagnets) are in fact inductive, it should work.
Grumpy_Mike:
No that is what the arduino is for, to take a reading, do some math and then send a command to change the output voltage. The power supply is only one component.
Perhaps if you narrowed things down to exactly what voltage
and current range you need it would be easier to build your own.
Right. That was I was thinking about. The problem I have (the major one) is how do I communicate Arduino with PS? I mean my range is not that big 0-36 V with 0-5 A (all DC).
shatun:
spycatcher2k:
Why not tell us what you are trying to make? I can't tell,is it a pressure to voltage converter, or do you want the voltage to be selected from a touch screen, or give a reading from a pressure transducer?What I try to is the project that uses MR fluid. It uses digital power supplies to power up electromagnets that will create magnetic field strong enough so the MR fluid will be solidified. This will create a pressure in pipelines that are connected to the the cylinder with actual MR fluid. What I need to do is have an engineer to input values via touchscreen and voltage will be changed according to the desired value. For example, the user input 120 psi -> 12.1 V. I researched and ended up finding h-bridge with PWM solution. Due to the fact that load (electromagnets) are in fact inductive, it should work.
This is why it's important to know the full context of a project in order to answer the question. Sometimes the answer is not what you suppose it is.
In this case, unless you want to reverse the coil voltage, you might not need a full H-bridge. You should be able to get by with a single MOSFET driver that you send a PWM signal to.
I mean my range is not that big 0-36 V with 0-5 A (all DC).
That is not an easy range, it is the lower voltage from 0 to 3V that are the most tricky.
Unless the power supply is designed to be a remote device it is hard to impossible to hack into it.
It is not clear if you want a constant current or constant voltage output but it looks like you don't need a bench power supply at all.