The document describes a door security alarm system using a magnetic reed switch, which activates when an intruder tries to access a designated area. It outlines the working mechanism, components required, specifications, and potential applications such as interfacing with microcontrollers for enhanced security. A detailed process for making a printed circuit board (PCB) and the configuration of various components is also included.

1. DOOR SECURITY ALARM SYSTEM
GUIDED BY:
Prof. Kalpana Pawse
Dr. prof. Mahesh Goudar
TEAM MEMBERS:
1.Vaishnav Lajurkar [E238]
2.Umesh Munde [E225]
3.Raviraj Sonar [E235]

2. DOOR SECURITY ALARM SYSTEM

3. UNDERSTANDING AND FUNCTIONING
 Security door alarms are simple electronic devices that trigger when an intruder or
trespasser tries to gain access to any designated area.
 They are a necessary part of today’s home security systems.
 There are a number of electronic configurations available to implement such home
security alarms. Here, we will take a look at implementing using a reed switch.
 The heart of this circuit is a magnetic reed switch.
 A reed switch comprises two ferromagnetic blades, separated by only a few microns.
 When another magnet comes close to these blades, the two blades pull towards one
another.
 Once touching, the blades close the normally open (NO) contacts, allowing electricity to
flow. Some reed switches also contain a non-ferromagnetic contact, which forms a
normally closed (NC) output. Any approaching magnet will disconnect the contact and
pull away from the switching contact.

4. WORKING & CONSTRUCTIONS:
This circuit can be attached to any entry point such as doors, gates, etc, or any storage unit
such as safes or drawers, where you want no intruders to trespass.
As the safe/door with one terminal of reed switch attached to the surface is opened & brought
close to the second terminal of the reed switch placed in close proximity.
The magnetic connection is made through mutual inductance & sends a control signal to the
base of the first BC547 transistor.
The collector output of the first transistor triggers the 5V buzzer & the alarm goes off.
 In order to turn off the alarm, you simply displace the door back to its original position, moving
the two reed switch terminals away from each other.
This demagnetizes the two terminals & turns OFF the alarm.

5. COMPONENTS USED IN CIRCUIT:
S.no Component Value Qty
1 Reed Switch – 1
2 NPN Transistor BC547 2
3 LED 5mm 1
4 Buzzer 5V 1
5 Resistor 680 Ohm, 100K 2
6 Capacitor 220uF 1
7 Soldering Iron 45W – 65W 1
8 Soldering wire with flux – 1
9 PCB – 1
10 DC Battery 9V 1
11 Battery clip – 1
12 Block Connectors – 1

6. BLOCK DIAGRAM OF CIRCUIT

7. CIRCUIT SIMULATION

8. PROTOTYPE ON BREADBOARD

9. CIRCUIT DESIGN ON KICAD
SCHEMATIC EDITOR
PCB EDITOR
PRINTED CIRCUIT

10. Process Of Making Printed Circuit Board (PCB)
Step 1: Path printed on
copper PCB
Step 2: Dissolving copper in
chemical
Step 3:copper is dissolved from
copper PCB excluding path

11. Step 4: By using sandpaper we clean
the circuit , then made holes for
assemble the components
Step 5: The Final Output
After assembling the components in PCB

12. SPECIFICATIONS:
• Two-part magnetically operated proximity
switch
• Standard normally open, high voltage
normally open and change over contact
configuration
• Moulded stand-offs to allow board washing
•RoHS Compliant
•Wave solder capable
DATASHEET OF
COMPONENTS
CAPACITOR
1
2
SPECIFICATIONS:
•Capacitance: 220uF
•Voltage: 25V
•Capacitor Type: Electrolytic
REED SWITCH

13. SPECIFICATIONS:
680 Ohm, 100K
For 680 Ohm:
1.Value: 680 Ohm
2.Tolerance: 5%
3.Power: 0.5W
4.Temperature : 55°C~155°C
For 100k Ohm:
•Highly Reliable 100K ohm Resistor
•±5% Tolerance
•Power Rating: 0.25W
•Package: Axial
SPECIFICATIONS:
• Switching and Amplifier
• High-Voltage: BC546, VCEO = 65 V
• Low-Noise: BC549, BC550
• Complement to BC556, BC557, BC558,
BC559, and BC560
RESISTOR
TRANSISTOR
(BC547)
3
4

14. SPECIFICATIONS:
․High luminous power.
․Typical chromaticity coordinates
x=0.30, y=0.29 according to
CIE1931.
․Bulk, available taped on reel.
․ESD-withstand voltage: up to 4KV
․The product itself will remain
within RoHS compliant version.
SPECIFICATIONS:
•Rated Voltage: 5V DC
•Operating Voltage: 5-8V DC
•Rated current: <30mA
•Sound Type: Continuous Beep
•Resonant Frequency: ~2300 Hz
•Small and neat sealed package
•Breadboard and Perf board friendly
5
BUZZER
6
LED

15. DEMONSTRATION OF PROTOTYPE

16. APPLICATIONS
1.Door Sensors:
1.Magnetic door/window sensors can be used to detect when a door is opened or closed.
2.These sensors typically consist of two parts: one attached to the door frame and the other
to the door itself.
2.Microcontroller/Single Board Computer:
1.Use a microcontroller (e.g., Arduino, Raspberry Pi) to interface with the door sensors and
manage the system.
2.Connect the sensors to the microcontroller to detect changes in the door status.
3.Wi-Fi/Bluetooth Module:
1.Integrate a Wi-Fi or Bluetooth module to enable communication between the
microcontroller and the application.
4.Alarm/Buzzer:
1.Include an alarm or buzzer to produce a loud sound when an unauthorized entry is
detected.

17. REFERENCES:
https://youtu.be/_j0csUukEzQ?si=yteuQXsHc_unjUiu
https://en.wikipedia.org/wiki/circuit
https://en.wikipedia.org/wiki/Transistor
https://www.electronicshub.org/what-is-reedswitch/