Download Wire free Door Guard

Wire free Door Guard
MAGNET
REED SWITCH
Protect your door with this tiny wire free Alarm generator. It uses the Neural and Earth lines of
Mains wiring to send the alarm signal
16
NO
9
C1 0.22
IC
10
HEF 4060
11
12
7
R3 470 K
R4 1 M
9 V DC
Phase
Not Connected
5
Neutral
R1
100 K
R2
100 R
8
D1
IN 4007
Earth
LED
Red
MASTER UNIT
Neutral
Phase
Not Connected
Earth
Zener
9 V1 W
D.MOHAN KUMAR
Piezo Buzzer
Alarm Generator
Protect your door with this tiny wire free Alarm generator. It uses the Neural and Earth lines of
Mains wiring to send the alarm signal. A Normally connected (NO) Reed switch and a magnet
will do the trick. When the door is closed, reed switch will be in the magnetic field and its
contacts remain closed so that the reset pin of IC HEF 4060 will be high. This inhibits its
oscillation and it remains standby. When an intruder opens the door, magnet and reed switch
move away taking the reset pin of IC to ground potential. IC starts oscillating using the
components C1 and R3.Blinking LED indicates the oscillations. After 1 minute, output pin 5
goes high sending the pulses to the Neutral line of Mains wiring.
The alarm generator includes a standard 12 volt piezo buzzer and a 9 volt zener. It can be
connected to any plug point in the house.
Fix the master unit in the frame of the door and Magnet in the door so as to keep them very
close when the door is closed. Enclose the circuit in a shock proof case
CAUTION: This circuit is going to connect to High Voltage AC. Phase should be left free.
Check the phase, neutral and earth lines properly. Connect the circuit only to neutral and earth
lines. Confirm the neutral and earth lines before connecting. Do not touch any parts when
connected to lines. Enclose reed switch in a shock proof case.
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