Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Fire smoke alarm circuit

  1. Oct 25, 2012 #1
    i am going to build this fire alarm.
    i got IC BT66 in place of UM66 . I want to ask that are BT66 and UM66 same or is their any difference of work. Also can anyone suggest any site where i can get internal circuits of the IC's UM66,TD2002,7805. thanx in advance . :smile:

    Attached Files:

  2. jcsd
  3. Oct 28, 2012 #2


    User Avatar

    Staff: Mentor

    Hi sandeepmrocks, http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

    I can't comment on BT66 vs. UM66. To find pinouts and further details, search on google using the strings UM66 "data sheet" or UM66 "application note".

    Unless your construction notes give you details of the light source and LDR, you may need to do some experimentation to establish a working arrangement for whatever light source and LDR you purchase.

    Happy experimenting! :smile:
    Last edited by a moderator: May 6, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook