Development of a Simple Sound Activated Burglar Alarm System

Thread Starter


Joined Mar 30, 2012
I am currently doing a school project , and i have decided to do a burglar system. I have found this scheme: and started until i reached the flip-flop. Many problems are around the flip-flop. It says pin 7 is connected to regulator but in fact, pin 7 is Vss. Also, it does not mention any other pins used. In the oscillator, it does not say which pins are used to connect to the diodes. The resistance near the transistor 2SD400 has no informations.

Can anybody help me with this?