One of possible use cases is to use value from this chip for "correction factor" while other part of circuit is performing measurements which are temperature dependant. Another is that you can also store value of measurement and value of temperature at that the same moment.
Nice IC; I could pair that with a Nixie digital voltmeter and have a cool thermometer. Thanks for the info. Another one on the long lists of these little Keritech projects.
MCP9700 (10mv celcius with 500mv offset for negative reading) nice for 12bit adc on 4.096v ref and MCP9701 (19.5mv celsius with 400mv offset) is ready for 8bit adc with 5v ref! LM35 is nice old device, i use on my large indoor thermometer.
On my 50A (non switch mode) psu for my radio gear there was a simple comparator circuit switching the fan on and off. It worked great but boy was it noisy when that fan kicked in. I replaced the circuit with a LM35 into an arduino nano and varied the PWM output to the existing fan switching transistor. Hardly ever hear the fan now.
Yes a ntc would definitely have worked just fine, but I happened to have a LM35 so that was used. Although thinking about it now I bet the comparator circuit I removed used one.
Nice presentation. You know that the Agilent U1272A the "700$ rugged 30K counts, IP54 water-and-dust resistant DMM with Low Pass Filter, low input Z mode, and continuity visual/audio alerts" standing next to it shows 18.3°C. Maybe it stood close to a cold drink on the table.
It would be helpful to check its accuracy with an ice bath that gives 0 C. I used to work with cold storage for fruit, typically at 0 C, so a small measurement error can be catastrophic. I have wondered about the accuracy of meteorological thermometers. The new electronic ones give high accuracy compared to the mercury ones used before 1990. The reading accuracy of mercury thermometers is only around 0.5 C. With climate change, fractions of a degree over long periods are important.
I had a lot of issues with mine. I had an LED in the same project and flashing it or turning it on impacted the temp reading. Giessing I was getting some kinda input voltage stability issues...
Great lesson well explain. I have two business projects one is to make 4mA to 20mA temperature transmitter and creating a variable frequency drive circuit from scratch I would like assistance in both projects can I reach you so that we can discuss?
Careful buying these fro aliexpress. I bought a pack of 20. None worked. Bought another 10 from another seller. None worked. Bought another 10 from a local online market place. None worked. Finally saw sense and bought genuine from RS Components and of course they worked perfectly.
@@tonyfremont sorry for the vagueness. My best guess is that they were not LM35's but just some random 3 pin package. Hooked up a voltage (to the correct pins) and they either did nothing at all or went up in smoke. Concerning the ones I bought locally I contacted the seller who then tested their stock and within in a day the product had been removed from their listing so I presume that they were all dodgy. I'd used them before from RS Components with no issue but as we all do, I figured I'd get 20 from China for the price of one from RS, but false economy!
@@TYGAMatt I bought mine from Aliexpress. All 5 worked OK. If they hadn't then I'd have had a refund. They might have been fakes. Mostly the sellers don't understand the function of the products, so never checks that they are functional before sending. They can't tamper with the feedback on their sites, so read it before buying. I have 50 sensitive gate SCR's that were branded and sold as something completely different. Got a refund and kept them. If I need a certified product, and in a hurry, then I do what you did. It's horses for courses.
@@peterrhodes5663 I agree with everything you say. I just put it down to experience. I buy a lot of electronic parts and equipment from Aliexpress and the LM35 was the only time I got a bad deal. Maybe just unlucky. Oh well..... Happy shopping 😊
Yikes. Just went to Mouser and Digikey to price 'em out -- if I'm reading this right, you've got a coupla hundred dollars worth of temp sensors in that little bag.
