Home and car alarm

This alarm is very simple to build and operate, because it is controlled by a key switch - it doesn't have complicated timing circuits and setting procedures like many other alarms: a great way to learn the basics. A key switch looks just like the ignition switch in a car: you turn the key one way and the switch is on; back the other way and the switch is off. Key switches are normally installed on or near the front door of the house or, in the case of a car, on the door or hidden somewhere within the vehicle.

What You Need

R1 220k ohms
R2 100k ohms
R3 1.2M ohms
R4 100k ohms
R5 47k ohms
C1 0.01uF MKT polyester
C2 0.01uF MKT polyester
C3 0.1uF MKT polyester
C4 22uF 16V tantalum
C5 0.01uF MKT polyester
C6 1000uF 16/25V electrolytic
Semiconductor Devices:
D1 1 N4004 diode
D2 1 N4004 diode
D3 1N4004 diode
TR1 BC548 NPN transistor
IC1 LM555 / NE555 timer integrated circuit
RLY1 1 Miniature relay with 9V coil, single change over contacts. Solder, hook-up wire, battery snap & printed circuit board (code ZA1635B).
You will also require a common 9 or 12 volt battery of reasonable capacity (two 9V alkaline batteries in parallel, for example) or some other 9 volt DC power supply (not normally supplied with a kit).

Download the assembly manual for the K-2635 Home and Car Alarm here.

Download Assembly Instructions