Easy Laser Alarm

MrThomas
Easy Laser Alarm

My plan is to make a lazer alarm system using the 741op amp and a 4017ic. The project will be triggered when the laser is blocked from shining on the LDR sensor this will result in an alarm beeper to be triggered and can be reset with a button or turned off with a small IR one button remote like the one you get from sparkfun electrionics. I already have to plan in mind and am sure I can make it.

COMMENTS

user
Patoff (Jul 10, 2015)
Hi, sorry to revive this thread, but a post about this project has recently been made and was wondering if a project update could be done to include the control of the alarm, the alert, etc. could be done over arduino or raspi so we can received email/sms notification?

Looking forward to your response

Patrick
user
engtg (Apr 27, 2014)
How did you get the laser to stay on?
user
Shyam (Nov 08, 2012)

There are few problems in this design. OP Amp IC 741 compares the voltage level of the battery and 4017 counter decoder output Q0 PIN 3 and counter decoder output Q0 can't exceed the battery voltage irrespective of LDR resistance change and this circuit will not increase count to set alarm at all. I think one resistor is missing that should be used to reduce the voltage on 741 OP Amp’s + input pin 3 to ground. Power source pin to IC 4017 and its connection is not shown. Output pin 4 of 4017 is wired OR with reset switch to Battery directly and this will discharge Battery quickly during reset. I think, this circuit is to be corrected by some expert editor and all such designs are to be reviewed before placing on the web. 4017 IC is not good enough for LASER Diode driving and perhaps a narrow angle intense LED may be in used. Prof. (Dr.) Shyam Sunder Tiwari Senior Scientist and Managing Director Sensors Technology Private Limited AM-51, Deen Dayal Nagar, Gwalior, MP 474001, India . .

user
ernie66 (Nov 08, 2012)

Is the schematic available? If so, where?

user
Sembazuru (Sep 29, 2012)

Quick spelling correction: it is spelled "laser". From Wikipedia (because I forgot the exact acronym): 'The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation.' Thus, there is no "z".

user
Sembazuru (Sep 29, 2012)

Otherwise this looks interesting. One question: Are there two parts (a laser emitter and a receiver), or are all the electronics contained in one part using a passive reflector to return the laser beam to the sensor?

user
MrThomas (Oct 02, 2012)

Thank you, didn't know that :) I'll ask if I can change the title.

user
MrThomas (Oct 02, 2012)

There is 2 part a laser reciever with the 4017 and 741op amp housed within and there needs to be a seperate emitter (the laser diode, that is encluded)

user
cozzz (Sep 06, 2012)

I'll buy several.

user
MrThomas (Oct 11, 2012)

Project is done! :D