why have separate current and voltage source?

[funkimunky]

I am learning about circuit analysis from a book and circuits with a separate current source and separate voltage source keep cropping up. Do these types of circuits exist in the real world and if so what kinds of applications do they serve?
Just to quantify my knowledge about ee I am a total beginner.

[IanB]

They are idealized extremes that can be used to support an understanding of how real circuits work. All real sources are somewhere in between one or the other.

Most real power sources like a battery for example approximate a voltage source, but current sources can crop up as useful elements in some kinds of circuit design.

You could model a real source equally well as a voltage source with a series resistance or a current source with a parallel resistance. Viewed from outside both would behave exactly the same.

[funkimunky]

Thanks for the reply it makes sense now. They just separate the voltage and the current so they can be ideal current and voltage sources to make it easier to understand.
I take it for learning circuit design you only need one power supply, I was worried that I might need to get another one.

[alm]

Most lab supplies can do both constant voltage (voltage source) and constant current (current source), depending on how you set the limits.