How to Know the Specific beta of transistor?

Discussion in 'The Projects Forum' started by ppoorrttee, Nov 23, 2008.

  1. ppoorrttee

    Thread Starter New Member

    Nov 23, 2008
    One of my problems in designing a circuit in our project is knowing the SPECIFIC beta of the transistor to be used in computing.

    Others say that it can be measured using multimeter and a resistor but I do not know at all. Anyone who knows about it?

    Thank you.
  2. Wendy


    Mar 24, 2008
    Generally beta is a loose figure with transistors. It has a wide range, even within a family, and you design for worst case.

    A lot of DVMs have the feature you ask about. It really is better to plan for worst case though.

    If you post a general schematic of your project I think we can talk you through it though, there is a lot of experience on this site with this.
  3. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    Specific beta does not really exist as it is constantly changing. If you design for one value of beta, your circuit may only work correctly some of the time.
  4. mik3

    Senior Member

    Feb 4, 2008
    You can make a simple circutis with two resistors and measure Ic and Ib and then calculate beta.


    This beta is valid only for the transsitor you tested. Also, even for this transistor it is not constant but depends on Vcb and temperature variations.