Need Help on LTSpice

Discussion in 'General Electronics Chat' started by bwilliams60, Nov 27, 2014.

  1. bwilliams60

    Thread Starter Senior Member

    Nov 18, 2012
    I just downloaded LTSpice and playing around with it, I was trying to build an astable multivibrator circuit and couldn't find a symbol for a speaker. Any ideas?
    Also, is there a larger library of symbols and components that can be added on to this library or is it, what you see is what you get?
    Just ran into another symbol needed....SPST switch?
    Last edited: Nov 27, 2014
  2. eetech00

    Senior Member

    Jun 8, 2013

    Best place to find components, symbols, models, help, etc., is at the LTspice group on Yahoo groups.

  3. ronv

    AAC Fanatic!

    Nov 12, 2008
  4. MikeML

    AAC Fanatic!

    Oct 2, 2009
    On the switch, the Help file is your friend:


    Here is an example of how to use it:


    Note the use of a pulsed source V2 to specify when the switch is closed and when it is open in the context of a time domain (TRAN) simulation. The default threshold voltage for the switch is 0V, so the switch is closed when V(on) > 0 and off when V(on)<0. I specified explicitly that the On resistance of the switch is 1mΩ. Read the help file entry for a full understanding of how rich the switch model is...

    On the loudspeaker, what do you think is an appropriate model? For most simulations, a 4Ω or 8Ω resistor works quite well. Only if you know something about a speaker's motion dynamics and enclosure is a richer model necessary...
  5. bwilliams60

    Thread Starter Senior Member

    Nov 18, 2012
    This circuit is out of a 300 in 1 kit that I use for my students. I am not sure on the ratings for the speaker and the switch used in the diagram is a simple SPST switch. It is a Maxitronix kit.