Programmable Power Supply

[Gamboa]

I am having problems controlling the voltage and current in a B+K precision programmable power supply. Since there is no driver available, I used the basic read an write example in Labview for serial communication, just making some modifications so that I could have two sequences, one for controlling the voltage and one for the current at the same time.

The aparatus responds nice if just trying to control the voltage or the current, but it does not work in combination or it does not retain the voltage/current value when I send the current/voltage.

Actually, it responds to both instructions nicely only when the current indicator has a nonzero value. And if it is switched from a nonzero to a zero value, It makes the actual voltage read to drop to zero.

Command strings sent to the aparatus are well written in all cases (so I guess is an internal variable problem) and I already tried to flush out and clean the VISA, nothing works.

I appreciate the help; I've attached the VI.

Rodrigo Gamboa

[ASTDan]

Hello,

That is how the power supply should work. I have worked with those before. If the current is 0 the voltage will be 0 Ohms law. The power supply can control to Voltage or current. If you want to control to voltage set the current to higher than you need, and set the voltage. The power supply will output the voltage you want. The current will be a function of whatever load you have on the power supply. If you have 0 resistance on the powe supply you will have infinite current. If you have infinite resistance on the power supply you will have 0 current.

Hope that helps

Dan

[Grampa_of_Oliva_n_Eden]

QUOTE(ASTDan @ Aug 13 2007, 03:11 PM)

Hello,

That is how the power supply should work. I have worked with those before. If the current is 0 the voltage will be 0 Ohms law. The power supply can control to Voltage or current. If you want to control to voltage set the current to higher than you need, and set the voltage. The power supply will output the voltage you want. The current will be a function of whatever load you have on the power supply. If you have 0 resistance on the powe supply you will have infinite current. If you have infinite resistance on the power supply you will have 0 current.

Hope that helps

Dan

Ditto Dan's reply.

If you figure out how to break Ohm's law, let me know, I still need an Noble Prize in Physics to add to my collection.

Ben

[crelf]

QUOTE(Ben @ Aug 14 2007, 05:15 AM)

I still need an Noble Prize in Physics to add to my collection.

You have other Nobel Prizes?!? Or did you mean to spell it incorrectly?

[Grampa_of_Oliva_n_Eden]

QUOTE(crelf @ Aug 13 2007, 04:28 PM)

You have other Nobel Prizes?!? Or did you mean to spell it incorrectly?

No, I spell most things wrong.

The breaking Ohms Law idea remnded me of a wise crack one of my Material Science Proffesor hit me with when I remarked, "So all I have to do is come up with a non-condicting form of steel and I can eleimnate rust?" He said "Sure, but let me know first. I would love to win a Nobel Prize in Physiscs." I got a similar answer from a physics proffesor when I asked if anything had a negative coefficient of friction. Imagine it, set something down on a flat table and it starts to accelerate! No, on second thought, forget everything I said.

Ben

[crelf]

QUOTE(Ben @ Aug 14 2007, 06:49 AM)

...set something down on a flat table and it starts to accelerate!

"http://www.fortunecity.com/banners/interstitial.html?http://www.fortunecity.com/lavendar/poitier/135/thermo.wav' target="_blank">In this house we obey the laws of thermodynamics!"

[ASTDan]

On the subject of professor wisecracks.

Here are the 3 fundamental laws of engineering

1. If it don't work plug it in

2. If it still don't work turn it on

3. Sh*t flows downhill

[peteski]

QUOTE(ASTDan @ Aug 13 2007, 05:15 PM)

On the subject of professor wisecracks.

Here are the 3 fundamental laws of engineering

1. If it don't work plug it in

2. If it still don't work turn it on

3. Sh*t flows downhill

Isn't there another one along the lines of "if it don't fit, use a bigger hammer" ?

-Pete Liiva

[i2dx]

QUOTE(peteski @ Aug 14 2007, 12:03 AM)

Isn't there another one along the lines of "if it don't fit, use a bigger hammer" ?

-Pete Liiva

and

"if it's to small, use duct tape"

[Gamboa]

Thanks a lot!!!; you are right, it is Ohms law in action, how could I forgot :headbang: ..hehehe. Now I can move on in a tranquil fashion but aware of the time that can be lost when experimenting due to incorrect suppositions.... :worship: .

Rodrigo Gamboa