Door-open alarm.pdf
Content
Door-open alarm
http://new.electronicsforu.com/newelectronics/circuitarchives/view_article.asp?sno=821&title=&id=...
ELECTRONICS ZONE
Engineer's Corner
Business Corner
Daily News
Login
Yellow Pages |
Register
Jobs |
eZines & Publications
About Us
|
Advertise
|
Contact Us
Tech Discussions
Innovators
Circuits
Videos
Tech Focus
Resources
Interviews
White Papers
Application Notes
Offers & Ads
Microcontrollers
Test & Measurement
Career Trends
Raspberry Pi
CIRCUIT
LAB
Pradeep G.
This door-open alarm uses an input sensor fixed at the corner of the door frame and a magnet fixed on the door panel close to the sensor. When the door is opened, the magnet moves away from the sensor, generating a controlling signal to sound the alarm. The circuit is built around Hall sensor A1301 (IC1), timer NE555 (IC2), a powerful magnet and a few discrete components. The sensor is a three-terminal device. The voltage generated by it depends on the polarity of the magnet. The presence of south-polarity magnetic field, perpendicular to the branded face of the sensor, increases the output voltage of the sensor. Conversely, the presence of north-polarity magnetic field in the same orientation as the branded face of the sensor device decreases the sensor output.
NE555 is wired as an astable multivibrator whose reset pin 4 is con-trolled by the sensor output. When the door is closed, the magnet is close to the sensor. Presence of north-polarity magnetic field generates a low voltage at the output of the sensor. As a result, pin 4 of NE555 also goes low and the timer does not oscillate. This de-activates the speaker indicating that the door is closed. When the door is opened, the magnet moves away from the sensor. The output of the sensor goes high and pin 4 of IC2 also goes high. The timer oscillates and the speaker sounds to indicate that the door is open. The speaker sounds until the door is closed. Assemble the circuit on a general-purpose PCB and enclose in a suitable case. Fix the Hall sensor at the corner of door frame and the magnet on the door, keeping its north pole (N) oriented towards the sensor. Align the sensor and magnet such that when the door is closed the output of the Hall sensor is low. The circuit works off regulated 5V DC. An IC 7805-regulated supply can be used for the purpose.
18
Post Comment | 7 Comments
28
25
9
denis
66 days ago
plz sir send me an abstract of this project
Reply 1 Reply
navneet singh
64 days ago
this was the nice project if u able then u will give me whole information regarding this project also animation of this project like how it is works..........plz
1 of 2
11/21/2012 11:17 PM
Door-open alarm
http://new.electronicsforu.com/newelectronics/circuitarchives/view_article.asp?sno=821&title=&id=...
Reply
t.azhagiri
Reply
51 days ago
why we should use sensor better we can use reed switch.
shivpratap
Reply
58 days ago
plz sir send me an abstract of this project
1 Reply
Caiden
Reply
35 days ago
Thats an intelligent anwser to a difficult question xxx
nitish miglani
Reply
48 days ago
sir can we use 9 volt battery instead of using 5 volt power supply circuit.
sindhu g.m
Reply
38 days ago
will this circuit works??does any one tested this
Magazines Electronics for You LINUX for You Facts for You Electronics Bazaar
Portals electronicsforu.com efytimes.com bpotimes.com linuxforu.com
Directories Electronics Annual Guide
Events EFY EXPO EFY Awards EduTech Expo OSI Days Electronics Rocks
News Verticals Electronics Infotech Linux & Open Source Consumer Electronics Science & Technology BPO
Educational Institute EFY Techcenter Kitsnspares.com
© Copyright 2012 EFY Enterprises Pvt. Ltd. All rights reserved. Reproduction in whole or in part in any form or medium without written permission is prohibited. Usage of the content from the website is subject to terms and conditions.
2 of 2
11/21/2012 11:17 PM
http://new.electronicsforu.com/newelectronics/circuitarchives/view_article.asp?sno=821&title=&id=...
ELECTRONICS ZONE
Engineer's Corner
Business Corner
Daily News
Login
Yellow Pages |
Register
Jobs |
eZines & Publications
About Us
|
Advertise
|
Contact Us
Tech Discussions
Innovators
Circuits
Videos
Tech Focus
Resources
Interviews
White Papers
Application Notes
Offers & Ads
Microcontrollers
Test & Measurement
Career Trends
Raspberry Pi
CIRCUIT
LAB
Pradeep G.
This door-open alarm uses an input sensor fixed at the corner of the door frame and a magnet fixed on the door panel close to the sensor. When the door is opened, the magnet moves away from the sensor, generating a controlling signal to sound the alarm. The circuit is built around Hall sensor A1301 (IC1), timer NE555 (IC2), a powerful magnet and a few discrete components. The sensor is a three-terminal device. The voltage generated by it depends on the polarity of the magnet. The presence of south-polarity magnetic field, perpendicular to the branded face of the sensor, increases the output voltage of the sensor. Conversely, the presence of north-polarity magnetic field in the same orientation as the branded face of the sensor device decreases the sensor output.
NE555 is wired as an astable multivibrator whose reset pin 4 is con-trolled by the sensor output. When the door is closed, the magnet is close to the sensor. Presence of north-polarity magnetic field generates a low voltage at the output of the sensor. As a result, pin 4 of NE555 also goes low and the timer does not oscillate. This de-activates the speaker indicating that the door is closed. When the door is opened, the magnet moves away from the sensor. The output of the sensor goes high and pin 4 of IC2 also goes high. The timer oscillates and the speaker sounds to indicate that the door is open. The speaker sounds until the door is closed. Assemble the circuit on a general-purpose PCB and enclose in a suitable case. Fix the Hall sensor at the corner of door frame and the magnet on the door, keeping its north pole (N) oriented towards the sensor. Align the sensor and magnet such that when the door is closed the output of the Hall sensor is low. The circuit works off regulated 5V DC. An IC 7805-regulated supply can be used for the purpose.
18
Post Comment | 7 Comments
28
25
9
denis
66 days ago
plz sir send me an abstract of this project
Reply 1 Reply
navneet singh
64 days ago
this was the nice project if u able then u will give me whole information regarding this project also animation of this project like how it is works..........plz
1 of 2
11/21/2012 11:17 PM
Door-open alarm
http://new.electronicsforu.com/newelectronics/circuitarchives/view_article.asp?sno=821&title=&id=...
Reply
t.azhagiri
Reply
51 days ago
why we should use sensor better we can use reed switch.
shivpratap
Reply
58 days ago
plz sir send me an abstract of this project
1 Reply
Caiden
Reply
35 days ago
Thats an intelligent anwser to a difficult question xxx
nitish miglani
Reply
48 days ago
sir can we use 9 volt battery instead of using 5 volt power supply circuit.
sindhu g.m
Reply
38 days ago
will this circuit works??does any one tested this
Magazines Electronics for You LINUX for You Facts for You Electronics Bazaar
Portals electronicsforu.com efytimes.com bpotimes.com linuxforu.com
Directories Electronics Annual Guide
Events EFY EXPO EFY Awards EduTech Expo OSI Days Electronics Rocks
News Verticals Electronics Infotech Linux & Open Source Consumer Electronics Science & Technology BPO
Educational Institute EFY Techcenter Kitsnspares.com
© Copyright 2012 EFY Enterprises Pvt. Ltd. All rights reserved. Reproduction in whole or in part in any form or medium without written permission is prohibited. Usage of the content from the website is subject to terms and conditions.
2 of 2
11/21/2012 11:17 PM
Sponsor Documents
Recommended
No recommend documents