# Questions for Independent Current Source

Discussion in 'General Electronics Chat' started by jproject, May 12, 2011.

1. ### jproject Thread Starter New Member

May 12, 2011
17
0
Hello everyone,

I've been learning some basic circuits as a first year electrical engineer student and I have some questions regarding independent current sources.

First question:
What are some examples of independent current sources? I'm having trouble imagining a current source that does not change at all when its voltage changes.

Second question:
If the independent current source is pointing to the right but the voltage sign on the current source is positive at left and negative at right like this...

+ -
-->

is it absorbing energy or supplying energy? My thought was absorbing energy using the sign convention method since the current is flowing to the right at the rate of whatever the independent current value is and the exiting side has a negative sign which means it absorbs (like resistors). But, my Irwin book says independent current sources will always "supply" current at the certain amount it is set to no matter what the voltage is (so a vertical slope on a voltage vs current graph). So, I thought I would ask you guys.

Thank you!

2. ### Jony130 AAC Fanatic!

Feb 17, 2009
3,957
1,097
In real life the "current sources" does not exist.
The current source is a theoretical device.
But we can make a "device" which will behave (in limited range) just like a current source.
http://sound.westhost.com/ism.htm#p1

I agree with Irwin book opinion, the Independent current sources will always "supply" current at the certain amount it is set to no matter what the voltage is across the current source.

3. ### jproject Thread Starter New Member

May 12, 2011
17
0
Darn, I wanted to see what happens if I put a battery with an independent current source in series (explosion? I hope?). Oh well.