i need a pcb circuit of super sensitive intruder alarm


Joined Jan 29, 2010
hi yash,
Welcome to AAC.
I do not expect any member will create a PCB for the project.
Have you tried creating the PCB artwork.?


Joined Sep 22, 2020
I can put it together on a proto board and send it to you, but I think that you'll find my prices are unreasonably high

Have you thought of using a bit of fishing wire and a bell? (As that is pretty much what that circuit is)

Back at uni I connected a motion sensor to the PCB of a wireless doorbell and that worked fairly well. (just for fun)

That might be a really quick way to monitor an area

I have also connected a reed switch to a wireless doorbell's button so that I can hear if anyone opens the front gate of my property from my studio (so that I don't miss deliveries)


Joined Jul 10, 2017
That is not the best of circuits. If you adjust it so it doesn't go off every time the sun comes out, it probably will not go off at all.


Joined Jul 11, 2016
  • that thing drains your battery ??? 5V battery ??? quite fast
  • the transmitter iR life-time gets quickly to it's half life even with a good heat sink
  • the schematic is mostly a "will do" for "quick assembly" (if the assembly -- combination of component "tolerances" -- appears to be successful)
  • the schematic is dependent on the battery voltage or it's state of charge . . . there is no low battery shutdown -- the last is required because of the LM358 has it's (optimistic) minimum supply about 4V and the 555 about . . . 2.6V . . . but approaching their lowest operational voltage limits the working parameters for the both chips change dramatically . . . parameters , such as , input sensitivity , misc. threshold voltages output voltage range ...
  • ... also your iR TX gets dimmer/lighter along the battery state of charge change
  • .
  • suggestion = use low voltage alternatives for Op amp and for the 555 . . . but there is also a lot of more here to pay your attention to

for starting you could tell where.. (an environment) ..this circuit is supposed to be operating , for how long , before the alarm is triggered and for how long the alarm should ring

it may be , that you want to add a supercapacitor --or-- a separate battery -- for the alarm to be capable of ringing for required time

etc. ...