Control eight 200mA power supplies

[GaryLT]

I need to control about eight 200mA power supplies.  Each supply should be programmable from minus 30 volts to plus 30 volts.  I need to be able to sequence the outputs (have one output go to 5V, next another output go to 8V, etc.).  The next thing I need is to output a serial data stream of about 10 bits. 

My test case would be the following:

Sequence several of the outputs to different voltages, this puts the ASIC I am testing into the mode I need. Then I need to have one of the power supplies output a serial 10 bit word to load a register inside the ASIC.

Does anybody know if this could be done with a DAQ-card?

[Wayne.C]

You could do this with a DAQ if you had power supplies that had an analog input that commanded the output voltage.  You could then use the DAQ to also monitor the voltages being applied to verify operation of the supplies.  You could even implement a closed loop control for precise control.  Closed loop might eliminate part of the calibration headaches.

For the serial part, you need to figure out how fast a supply will react to a change in commanded voltage.  If the change is not fast enough, you will need some sort of analog switch or relay to switch between 2 different supplies that you have preset to the desired levels.  This will let you turn a voltage of a variable level on and off. ( I'm assuming that you need to vary the level as part of the test. ) You will probably need LabView RealTime in either case to make sure that the timing of test sequence and serial communications are tightly controlled.

[MickeyD]

Hi Gary,

M Series DAQ cards provide a very flexible tool.  You can have Digital Input and Output, Analog Input and Analog Output.  The question is how are you going to control the Power Supplies?  Do they take digital commands, or can you input an analog voltage as centerbolt mentioned?  If you do need an analog output to control the power supply, then the standard multifunction DAQ cards will not work for you, because they only have at the most 4 analog outputs.  There are dedicated Analog output cards that could provide this functionality. 

The other idea is that you want the DAQ card to be your power supplies for you.  If that is the case then that would greatly change what you require from the card, and no single card will be able to do that for you.  Finally how does the power supply output a 10 bit serial word, is that inherent in a piece of hardware you already have, and if so how do you tell it to make that output. Please get back to me and we can probably find a solution that would work for you.

Have a great day,

Michael D
Applications Engineer
National Instruments