Laser Gun/Pointer Circuit: Need Help!

Discussion in 'General Electronics Chat' started by Durach, Feb 26, 2007.

  1. Durach

    Thread Starter New Member

    Feb 25, 2007

    I found this circuit in the book 'Robotics, Mechatronics And Artificial Intelligence' by - Newton C. Braga

    It seems like quite a simple circuit but I can't make head or tail of how it is supposed to act like a laser gun. :confused: The book doesn't give any explanation as to how the circuit functions. Can anybody please explain to me its working? I was told that the transistor BD135 is used to switch ON/OFF the laser module. Then, what's the use of the cascaded IN4002 configuration?

    Any other model of laser gun with explanation is also welcome. :)


    Replies are really appreciated.
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    Placing a positive voltage where the schematic says "+ voltage in" will cause the BD135 to turn on (5 to 9 volts should work fine). The three 1N4002's keep the voltage drop across the laser module in an acceptable range. Be sure to use the chart to properly select the resistor.
  3. WiredGuy

    New Member

    Feb 26, 2007
    I agree. It seems simple, but I can't copy it.