Now I am going to discuss about a simple, effective and funny circuit! If anybody inter into your door you can easily sense his attendance by using this system, however, you are sleeping!
For applying this method you have to collect some component, which are given below:
1. One Resistor of 10 k Ω.
2. One Resistor of 68 k Ω.
3. One Resistor of 1 k Ω.
4. Two non-polarized capacitor of 0.01uF.
5. One 1uF/15volt Polarized capacitor.
6. One timer IC, which number is 555.
7. One speaker, which resistance is 8 Ω and power is 0.5Watt. You can also use radio speaker instead of it!
8. Copper wire.
Now connect according to the following picture!
Now you have to connect copper wire behind your door in such way, if anybody opens your door, then this copper wire will be uprooted automatically. When this wire will be uprooted, then a sound of one kHz is produced! As a result your sleep will be broken instantly.
Please note these:
1. Every resistors of this circuit are ¼ watt.
2. This circuit can be driven by 5-15volt; you can also use 6volt/9volt/12 volt battery.
3. You have to apply positive voltage to the 1st pin of the IC.
4. You have to apply negative voltage to the 8th pin of the IC.
5. You have to connect one end of the thin wire to the 1st pin of the IC, and other end will be connected to the 4th pin of the IC.
6. You should also be alerted, because wrong connection can be damaged your IC.