This house alarm circuit has open and closed loop sensor and has self shutdown function. The delay after trigering can be adjusted from 1 minute to 12. The delay before trigering is 13 seconds. Offcourse all this timmings can be change with litle changes to few passive parts.
The inportand parts in the circuit are 3 ICs CD4011 which are well known quad2 input nand gates, a timer 555 and the CA3097E.