Hi all
I will explain exactly what I am intending to do.
I am building a power supply for a resistive load.
The load under consideration is a kind of nichrome fuse,of which I have to test some parameters with my equipment.
Current should be variable from 1A to 5A in steps of 1A constant.
Voltage need not matter and I would be building a CV of 15V (I feel would be sufficient)
Now I have to program a one time pulse starting at 50ms up to 500ms in steps of 50ms.
After everything is set and I press 'FIRE' or something I will switch on a MOSFET to give a path to the current through the Load.
I am unable to understand a few things here though.
I primarily will set current with a fixed resistor bank and using a short circuit instead of load.
e.g. For 3A=15v/5E so would use a smaller R at say 4.5E to get a higher current. 15V/4.5E=3.33A (considering unknown load)
After this is set,I input value of pulse at say 50ms.
After this,I put the load on O/p and press 'FIRE'.
Now during this 50ms time I should limit the current w/o any overshoot at 3A by using some kind of variable resistor.
If the Load value is 5E then current will come down to 1.5A,which the circuit should compensate by either increasing the voltage or by a constant current source.
If I use a transistor as a variable resistor,wont the error correction take some finite time?which will not be permissible.
I hope I am clear enough..
Thanks and please get back with your valuable suggestions!!!
I will explain exactly what I am intending to do.
I am building a power supply for a resistive load.
The load under consideration is a kind of nichrome fuse,of which I have to test some parameters with my equipment.
Current should be variable from 1A to 5A in steps of 1A constant.
Voltage need not matter and I would be building a CV of 15V (I feel would be sufficient)
Now I have to program a one time pulse starting at 50ms up to 500ms in steps of 50ms.
After everything is set and I press 'FIRE' or something I will switch on a MOSFET to give a path to the current through the Load.
I am unable to understand a few things here though.
I primarily will set current with a fixed resistor bank and using a short circuit instead of load.
e.g. For 3A=15v/5E so would use a smaller R at say 4.5E to get a higher current. 15V/4.5E=3.33A (considering unknown load)
After this is set,I input value of pulse at say 50ms.
After this,I put the load on O/p and press 'FIRE'.
Now during this 50ms time I should limit the current w/o any overshoot at 3A by using some kind of variable resistor.
If the Load value is 5E then current will come down to 1.5A,which the circuit should compensate by either increasing the voltage or by a constant current source.
If I use a transistor as a variable resistor,wont the error correction take some finite time?which will not be permissible.
I hope I am clear enough..
Thanks and please get back with your valuable suggestions!!!