I have a 30V - 100A power supply that I want to control using a -/+ 10V NI DAQ. I want a relay between the current output of DAQ and the power supply. Please advise the specification of relay to use. I'd appreciate a comment on how to connect it also.
Sorry, i can not quite understand, what do you want to control, the voltage or the current of the power supply?
and how will be the relation between the power supply and the value of the DAQ module?
Remus Vladimir Vladimir Ghincu I have written a software to control the current output of the power supply. The DAQ is connecting the software to the Power Supply. It is a +/-10 V NI DAQ and I scale it to 100 AMPS from my code. I want to use the relay to prevent power surge which destroyed my previous NI DAQ.
Something is not OK with your design.
To control the current of the power supply you need some piece of hardware, not only some software. You should not have any source of voltage surge, which could destroy something
To prevent any power surge you should use a voltage suppressor , not a relay.
Anyhow i should see the whole design to establish the right solution
STOP !!!!
100 A is a high current, you cannot cut it so easy. Every time you cut the current , a self-inducted voltage (depending on the inductivity of the circuit), will appear (which can destroy a lot of electronic parts), if not properly clamped.
This approach ( to control the load by ON/OFF of the power supply with the help of the relay) is not the ideal choice.
On the other hand NI DAQ means : National Instruments Data Acquisition
This is an electronic module designed to measure and store digitally a signal (voltage signal) NOT to control some other module.
To correctly design the circuit , one has to know exactly the specification of the system.
It is not so simple how you think
let's say you have a series resistor of 3 ohm
The power dissipated on it is P = RxI xI = 3 x 100 x 100 = 30KW
Do you know how a resistor for 30KW looks like , how large it is and how much does it cost???
The power electronics has found other solutions for this kind of problems
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