Hey Peoples...Im quite new to practical PSU design, and would really appreciate help designing :

A variable output power supply -switching - with volt range 0 - 37 v and current range 0 - 3A with polarity consideration.

The output of the PSU is meant to automatically change depending on the

specs. of the device its connected to.

Answers with circuit diagrams would be greatly appreciated.

Tnx guys.

 

You don't make sense.
A variable output voltage power supply has a regulated output voltage. Its output voltage is not "automatically" changed by its load unless the load needs more current than the current setting of the power supply.

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Uncle $crooge

 

That would indeed be one smart and useful PSU, however I don't think it's been invented yet in spite of being a desirable feature. Perhaps you have stumbled on a million dollar idea. But how to implement it

Lefty

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Measurement changes behavior

 

This is not just for one specific load, its meant to be useable with different loads of different volatage and current requirements.

Do you get where I'm coming from now?

 

Yes, we get your idea, however there is no way for the PSU to automatically 'know' what the load's proper voltage requirement is. It would just keep raising it's voltage, which would increase the current going into the load, up to the limit of the power supply or until the load device burned open.

Think of the load being a 6 volt, 1 amp lamp, the PSU would have no way to automatically know that the lamp has a maximum 6 volt limit and the PSU would just keep raising it's output voltage until the lamp burned out.

Do you get where we are coming from?

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Measurement changes behavior

 

Do you mean its user adjustable over those volts/amps or it adjusts itself automatically.??

Which

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Eric
"Good enough is Perfect"

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ericgibbs: i mean adjusts automatically.

Thing is lets assume I'm able to let my PSU know the load voltage and current requirments, how do I then adjust its output...maybe via

the IC ...as in how do i let my IC ouput voltage change, is there anything like a digital resistor u could program or control in a
way...something along those lines...

 

Its difficult to advise you without knowing what the project is?

There are digital resistors that can be set, usually by a micro-controller, BUT the settings of the digital resistor,
for different KNOWN loads would have to preprogrammed into the micro.

Tell us what you are trying to do.

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Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

Take a look at the bench power supply on Mondo electronics web site.
http://mondo-technology.com/

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

 

I feel the term 'LOAD" is related to current and it purely depends on load resistanc or inductance etc, nut not a voltage related. it is true that as the applied voltage reduces the current will reduce for the same load.

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Regards,
Sarma.

 

if load requires more I and cant have it then u get voltage drop ( short circuit) viceversa . do u want a power supply some thing like a switch mode one that gives u what u need ( computer power supply). all bench power supplys just about sense current (I )needs BUT YOU HAVE TO TELL IT BY TURNING THE KNOB . what are u using to psu for ?

 

What do you mean by polarity consideration?

It sounds like you need more experiance before attempting such a project. I advise you try something like a 1.2V to 15V LM317 supply before building something more complecated.

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