Discussion in 'General Electronics Chat' started by nepdeep, Sep 3, 2012.

1. ### nepdeep Thread Starter Member

Sep 14, 2011
139
0
Hi,
I am electrical engineering student. I have a project where I should build the High speed transient load step. The specificaiton is it should work on lower voltage and the transient should be fast. I dont know where and how to begin. Can you tell me what can I study befor I begin and may be the procedure to build the product.

2. ### kubeek AAC Fanatic!

Sep 20, 2005
4,687
805
How fast is fast?

3. ### nepdeep Thread Starter Member

Sep 14, 2011
139
0
as I said give me basic guidelines, then we will talk about how fast ?

4. ### kubeek AAC Fanatic!

Sep 20, 2005
4,687
805
So if I understand you correctly you want a variable load with fast transition between two load states, right? Apart from the last question, you need to say if the load is for DC or AC signal, as that also changes a lot.
From what you said so far a relay switching a resistor looks perfect.

Sep 14, 2011
139
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6. ### ramancini8 Member

Jul 18, 2012
447
119
Your reference seems to tell the story; what else do you want? Jim Williams was one of the best analog engineers in the world, and you can trust his material to be tested.

7. ### bountyhunter Well-Known Member

Sep 7, 2009
2,498
507

http://www.ti.com/lit/an/snoa507/snoa507.pdf

8. ### #12 Expert

Nov 30, 2010
16,672
7,314
Basic guidelines:
define, "fast"
define, "lower voltage"
decide if you are putting a load on an AC wave or a DC voltage level.
Now that you have posted an excellent reference, say what part of it is not sufficient for your needs.

9. ### nepdeep Thread Starter Member

Sep 14, 2011
139
0
Now I know something....
Voltage as low as 1 volts
Current as high as 10 amps..
fast....response should be stable at most 100nano seconds

one thing...i am second year electronic student...i am not clear about..what is meaning of load working on AC wave or DC voltage level...cause regulator I'm working I suppose is a DC-DC converter..thanks #12 in advance

10. ### #12 Expert

Nov 30, 2010
16,672
7,314
When your needs were completely undefined, you might have been trying to put a load on the power line voltage. That would be an AC wave.

Now that you have defined a DC voltage and want to put a load on that, the math is very different. The link in post#5, circuit 2, will stabilize in about 25 nanoseconds. You have only to change the current from 1 amp to 10 amps by using a different MOSFET.

11. ### bountyhunter Well-Known Member

Sep 7, 2009
2,498
507
The circuit I posted does a 0 - 3A load step in about 20 ns.