Problem Using a DC Power Supply

Have you got a load connected? If not no current will flow. Try connecting a

12v light bulb of around 10 to 20W. Set the output voltage to 12V and the current limit to max. The bulb should draw around 800mA(10W) or 1.6A (20W). Then you can wind the current limit down to see what happens. Note that setting a lower current limit than the bulb draws will reduce the output voltage. That's how they limit the current.

Note that you should probably treat the current knob as a safety device to limit the power in the even of a fault in the load eg When hooking up a new circuit you have built for the first time. It also protects the output of the power supply if you accidentally short circuit the output.

It's not allways possible operate a bench power supply in "current limit mode" continuously as some power supplies can overheat. Read the instructions for your model. Some models are ok with this.

CWatters inscribed thus:

I have one! That is exactly how it works. Current limiting is great for testing small thermister's using self heating.

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Best Regards:
                      Baron.

Hi, Frank. Great question. The easiest way to adjust current limit for the two 0-32V supplies is to turn the current limit adjust all the way down, short the output terminals, then adjust the current dial up to the desired maximum current. You can then use the power supply in voltage mode, and be secure that output current will be limited in the event something goes wrong or the load becomes excessive.

Note that this does not work for the 5V supply, which has a fixed 5A current limit.

Good luck Chris

Are you sure you're really cut out for this electronics lark ?

Just a quick test.

What do volts times amps make ?

Graham

THe current setting is only the max load, you need a load on it first. Most likely you do not have a function where it shows you the set point. the display you have is simply a current monitor not a current set point display. Most likely the control is near the average spread range for example. Lets assume your supply is a 10 amp unit.. set the control at 50% should yield you a 5 amp max load before it clips back. etc... You may have an option to allow you to see the set point which how ever, if so? It should force you to do something else to the controls so that you can see the set point? Like push on the knob etc... other than that, I think it's like most others. Start low, and if you don't get enough current, just bring it up.

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"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
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A lot of unwanted miss fits?

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"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
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Whatn do you mean. missfits? if you have nothing useful to contibute.........

To set the current limit, set the current to minimum, and the voltage to near minimum. Short the output terminals and turn the current up to the desired reading. (Don't let the supply in this condition for long, as it generally produces quite a lot of internal heat.)

Then remove the load short and set the desired voltage reading. Now the supply will deliver the set voltage unless the load tries to pass more than the set current, at which point, the voltage will be reduces to something below the set voltage that holds the current at the set current.

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A man with no sense of humor? or did I get the gender wrong?

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"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
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Are you cut out for this electronics lark?

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Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Supply

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Why, whats your gender, hermaphrodite I suspect. If you understand, then you know what you can go do to yourself don't you LOL

the current meter only shows what is being drawn from the supply... you can vary the volts but if nothing is drawing any curernt, then it will show 0... put a car side-light bulb across the terminals and vary the voltage - the resistance of the bulb is constant so the current goes up and down proportional to the voltage - you might like to google "ohm's law" and "kirchoff's law" coz they will explain everything everyone has said here.

Supply

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Such a sophisticated mentality you have there. Almost sounds like my wife and she knows everything!.

--
"I'm never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5