current VS voltage output

Discussion in 'General Electronics Chat' started by binod, Jun 3, 2009.

  1. binod

    Thread Starter New Member

    Apr 3, 2009
    hi all ,
    i donot understand what is the difference between current output and voltage output. many times the question comes like wheather the output is current or voltage .i dont understand this as because when voltage will be there then only current will be there....

    please help
  2. leftyretro

    Active Member

    Nov 25, 2008
    You need to study basic Ohm's law. There can be voltage output without current flow if there is no load circuit, think of a battery sitting on a table unconnected, there is voltage potential at the terminals but no current is flowing. But there must be a voltage potential avalible for current to flow.

  3. AdrianN

    Active Member

    Apr 27, 2009
    In a nutshell, a power source that has its internal resistance very small versus the load connected to it (Rint << Rload) is a voltage source. By contrast, if the power source has its internal resistance a lot larger than the load, is a current source.

    Examples of voltage sources: a battery, lab power supply, the output of a transistor emitter.

    Examples of current sources: the output of a transistor collector, a specially designed current source like the Newport's 500B series laser diode driver: