LASER CONTROLLED ON OFF SWITCH USING 555 TIMER BASIC ELECTRONICS PROJECT


HOW TO MAKE LASER CONTROLLED ON OFF SWITCH?

This is a basic electronic project on how to make a laser controlled on/ off switch using a 555 timer. Below is its schematic diagram.



This circuit is built around a 555 timer using very few components. Since the circuit is very simple, even a novice can easily build it and use it as a controlling device.

A laser pointer, now easily available in the market, can be used to operate this device. This circuit has been tested in operational conditions from a distance of 500 metres and was found to work satisfactorily though it can be controlled from still longer distances.

 Aiming (aligning) the laser beam exactly on to the LDR is a practical problem. The circuit is very useful in switching on/off a fan at night without getting off the bed. It can also be used for controlling a variety of other devices like radio or music system.

The limitation is that the circuit is operational only in dark or dull-lit environments. By focussing the laser beam on LDR1 the connected gadget can be activated through the relay, whereas by focussing laser beam on LDR2 we can switch off the gadget.

The timer is configured to operate in bistable mode.

6 comments:

  1. Hi,
    I tried this circuit but am not getting correct output. while the diode across relay is forward biased it gives only 0.8V while reverse biased it gives around 4v and high and low pulses are not been generating in output while respective LDRs are on...

    ReplyDelete
    Replies
    1. in the ckt diode d2 orientation is wrong & try using lower values of resistors (1k to 5k)in place of r1 r2
      it will help your ckt to be operational under bright light

      Delete
    2. thank u my dear frnd>>>>>>>>

      Delete
  2. hey guys i have built this project and uploaded its video on youtube
    link is
    http://www.youtube.com/watch?v=BDLjmKqA_Y

    ReplyDelete
  3. can u upload your schematics on this... or email to my account... pls... mac_do00@yahoo.com... Im having a problem building this... help pls...

    ReplyDelete
  4. Please give correct schematic on my email rkhobragade@gmail.com

    ReplyDelete