Re: its a current source
rshankar86 said:
I am a rookie in this ocean..... i m fascinated and excited by the fact that u are designing a dc current source of 1000 A magnitude .
The primary aim of my circuit is to convert a given AC source into regulated current supply of range say (1-10)A. Ironically, i wanted to make the regulation part a bit different. This is why I decided to use SCR. But now I have realized tat SCR's ripples wont give me a constant dc o/p required.
thank u very much all 4 ur guidance....
Shankar Ramanathan
Ahh well this is different!!!! IF you are sure you really are after a current-source, (ie sometihng that will produce alot of amps, and obiously some voltage)
At work we have 3 kinds of supply's
1) Power. 45KVA variable freq 3ph power supply
2) High voltage. 400V DC (tunable) with a tunable current-limit upto 40A
3) High current. a 20V DC (tunable) with a tunable current-limit upto 600A
So as you can see what we use as a current-source really is a power-supply but depends on its use
If we set the voltage high enough but set a current-limit it will act as a current-source sitting in current-limit
IF we set the voltage low enough but the current high enough it will act as a voltage source sitting in voltage-limit
With the added infomation abt supplying from AC then Thyristors/SCR are the ideal choice.
How? Fully-controlled rectifier with the firing angle controlled via a current-loop. AND to make it a current-source a nice big inductor, this will also smooth out any current-ripple giving you a current-ripple that is related to inductor size
You will definitly want to use a step-down transformer, what is the highest voltage you perceve you will need (bearing in mind for a current-source to work it's voltage-limit must be in excess of the load voltage)