Electric Fire Alarm
Review: 5 - "A masterpiece of literature" by John Doe, written onMay 4, 20020
Electric Fire Alarm

Electric Fire Alarm

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  • Product SKU: LGZK001
₹ 129 ₹ 169
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  • Product Code: LGZK001
  • Technical support - available on email
  • Handmade
  • Make in India
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  • Video support to be purchased separately
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  • Unsolder Zero PCB
  • Includes all Passive Components, ICs, Zero PCB & Connecting wires.
  • Documentation: Description, Component list, and Circuit diagram.
  • Power Supply: No battery included, Includes 9 Volt battery cap only.
  • Video tutorial is available on YouTube.

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A fire alarm is an electronic sounder or a bell. The sounder makes a loud high pitched sound to alert people that there is a fire in the building. Here the fire alarm devices sense the heat and activate the loud noise. There are many typical and complex fire alarm circuits available in the form of standalone devices. But this is a simple fire alarm circuit using LM358. This is a simple project which detects the fire and triggers the siren sound or a buzzer.

This Electric Fire Alarm Circuit is based on IR(infra-red) sensors. Fire has a lot of IR rays. In the given circuit IR sensor and R2 works as resistance divider networks. As the infrared rays fall on the sensor its resistance decreases and the value of R2 is fixed. This causes the voltage at pin 3 of the operational amplifier to increase. (on its non-inverting terminal). If the voltage set at pin2 of the operational amplifier (LM358) becomes less than the voltage of pin 3 then the output of the op-amp(operational amplifier) becomes high.

This Electric Fire Alarm Kit is the fundamental principle of operation of any operational amplifier ie if the voltage of the non-inverting amplifier becomes higher than the voltage of the inverting amplifier the output becomes high. The led D1 is used here for indication purposes only. The resistance R1 is used to protect the LED from overcurrent damage. The buzzer is an active buzzer(BZ1), whenever its pin1 goes high, it starts beeping.

Schematic Diagram

Physical Attributes

  • Dimensions (cm) L x W x H : 15 x 12 x 5
  • Weight (gm): 50

Product Video

Customer Reviews

Based on 5 reviews
Adithi V S
Very Good

Exactly what I was looking for

Verma Prakhar
Gud product but little bit costly

Everything was provided except battery...Otherwise Gud product

Ashutosh Sharma
Excellent product with all materials provided ????

All the material of good quality was provided

Sudhanshu Mishra
Life saving

Thank you very much for such an amazing product since it helped me a lot to earn marks in my last year's boards practical.

Manaswini Padhi
Good product

Nice project