help with a design on zener diodes

Discussion in 'Homework Help' started by dwchino21, Jun 20, 2007.

  1. dwchino21

    Thread Starter New Member

    Jun 20, 2007
    Design a zener shunt regulator to provide a regulated voltage of about 10volts. the available 10 volts, 1-W zener of type 1N4740 is specified to have a 10 volt drop at a test current of 25mA. At this current, its Rz is 7 ohms. The raw supply available has a nominal value of 20 volts but can vary by as much as + to - 25%. The regulator is required to supply a load current of 0 to 20mA. design for a minimum zener current of 5 mA.

    A) find Vz0
    B) calculate the required value of R
    C) find the line regulation. what is the change in Vo expressed as a percentage, corresponding to the + to - 25% change in Vs?
    D) find the load regulation. By what percentage does Vo change from the no load to the full load condition?
    E) what is the maximum current that the zener in your design should be able to conduct? what is the zener power dissipation under this condition?
  2. dwchino21

    Thread Starter New Member

    Jun 20, 2007
    i need help because i dont even know where to begin with this problem.
    1) I dont understand even how to draw a graph out without numbers.
    2) dont even know what a zener shunt regulator is or looks like
  3. niftydog

    Active Member

    Jun 13, 2007
  4. Papabravo


    Feb 24, 2006
    You forgot to mention that your textbook, class notes, and instructor have had nothing to say on this topic. Is that correct?

    Edit: I went to the hyperphysics site and it should give you what you need.