currant and voltage

Discussion in 'General Electronics Chat' started by blaze979, Jun 23, 2011.

  1. blaze979

    Thread Starter New Member

    Apr 23, 2011
    it is given that some circuits control flow of electrons through currant and some through voltage. does the control of voltage not translate to the control of currant? what is the difference?
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Can you provide a link or a cite to the origin of this statement?

    Current is the flow of electrons. Controlling current with current would take some specific circuitry.

    See Ohm's law.

    Might you be trying to understand transistor action? The PN junction requires a voltage to start current flow, but then requires current control to regulate conduction.
  3. Adjuster

    Well-Known Member

    Dec 26, 2010
    Voltage and current are not always simply related. The flow of electrons or other charge carriers constitutes an electric current. Note the spelling: current (a currant is a type of fruit).

    Voltage, or rather the electric field produced by a potential difference, tends to make charges move, and so voltage and current are generally related. In a resistive circuit there is a simple proportional relationship, but the situation is more complex in many things such as semiconductors, gases or vacuum devices.

    In some cases the current flow is directly controlled only by the applied voltage, but in other situations the current flow is strongly dependent on some other quantity, such as light intensity falling on a photocell. For instance, in the case of a transistor, a small current flowing base to emitter can determine a bigger current flowing collector to emitter.