These days electronic room thermometer is very popular, though it is expensive. Now here we designed a simple and cheap electronic room thermometer using a temperature sensor and op-amp 741.
Circuit Description of Electronic Room Thermometer using Op-amp 741
The heart of the circuit electronic room thermometer is IC1 (LM3911), which is used here as a temperature sensor. The output of this IC is variable according to temperature change. Its output increases at the rate of 10mV/0C rise in temperature. At 00C its output is 2.73V.
The output from IC1 is given to the input of IC2 (Op-amp) for necessary amplification. Amplified output from in 6 is given to micrometer through potentiometer VR2. The sensitivity of the electronic room thermometer is ± 0.10C. The range of this thermometer can be adjusted by VR1.
 PARTS LIST OF ELECTRONIC ROOM THERMOMETER
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Resistor (all ¼-watt, ± 5% Carbon) |
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R1 = 33 KΩ R2 = 330 KΩ R3 = 3.3 KΩ VR1 = 100 KΩ VR2 = 2.5 KΩ |
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Semiconductors |
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IC1 = LM3911 IC2 = µA741 |
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Miscellaneous |
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M1 = Micrometer |
This circuit is not working…
I checked and verify it, and it is working well.
Thank you sir. I’ve made the circuit and it is working
what is micro meter ? is it guaga measurement ?
No it is to show the deflection. i.e. it is used to show the temperature.
Dear Sir
If there is any substitute of Micrometer please tell.
thank you.
.
Where can i find Lm3911 ic? Also, what is the range of the micrometer?
You can bye LM3911 from any electronic reparing shop. And you can use any ammeter in micro-ampere range (often used in physics lab)
Plz explain me whole working of this circuit..like when i see the change in temperature or temperature of rom. In this ckt …plz reply fast
Sir , Can you please explain the working of this cicruit in detail ?
Hi sir,
Can digital display be used as an alternative to micro meter?