I'm developing a project of fire alarm.
according to your view which temperature detecter can be used.
Actuly i'm connecting temp senser to microcontroller.

Can anyone sugges me any IC/CKT which just sence the temperature variation (i don't need to measure it)?

Thank you .Friends...

 

Look at this..... http://en.wikipedia.org/wiki/Thermistor

 

Fire alarms generally use smoke detectors, not temperature sensors.
The selection of temp sensor depends on what temperature will be considered a fire. For example some sensors with digital outputs are available up to 150°C, while linear sensors could go up to 250°C, and thermocouples maybe even up to 1000°C.

 

Hi,
Maybe you can use Dallas DS1820. It has upper and lower trigger points stored in NVRAM. Only eat 1 data pin of micro (bidirectional). Temp range: -55 to +125C

 

Look at this..... http://en.wikipedia.org/wiki/Thermistor

How can i forget Thermistor , even i've written a one page short note on exam..
however somthing learn positive today..
Thanks BillB3857.

 

How can i forget Thermistor , even i've written a one page short note on exam..
however somthing learn positive today..
Thanks BillB3857.

Hope it was a help. Are you going to be looking at rate of change to determine a problem?

 

I have also make few fire alarm project using metallic strip temp. depended, in school time and now few month's back by using IC 741 with NTC thermistor and ldr.

 

Fire alarms generally use smoke detectors, not temperature sensors.
The selection of temp sensor depends on what temperature will be considered a fire. For example some sensors with digital outputs are available up to 150°C, while linear sensors could go up to 250°C, and thermocouples maybe even up to 1000°C.

Actuly it's my final semester project, so can not put smoke senser cause i've to make out as compect as possible.

My actual idea was to fire a match and take it near senser, and led/alarm starts.
I'm Also suppose to use a skimmit trigger for compassion with actual temp.

 

Hope it was a help. Are you going to be looking at rate of change to determine a problem?

I will place a schmitt trigger to compare with actual temp..

And yes you have helped a lot..

 

Hi,
Maybe you can use Dallas DS1820. It has upper and lower trigger points stored in NVRAM. Only eat 1 data pin of micro (bidirectional). Temp range: -55 to +125C

Does DS1820 is widely used temp senser/detecter ?
AS i guess DS1820 may not be available in my city.
Otherwise I can use thermister,but it's unreliable ...

Any alternative ??

 

Here is more interesting reading..... http://www.capgo.com/Resources/Temperature/Semiconductor/Semi.html

 

There are various mechanical temperature sensors that could be used. As to an IC I'm quite fond of the LM335 but you've got to learn how to work with the chip and will have to build the interface circuitry.