Is my LM35 sensor damaged or not?

Projects General Guidance
21

This.

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Im thinking they might be damaged from ESD, although their datasheet shows 2500V and is pretty high value to resist. Ive seen way lesser, like 1000 and even 500V ESD protection and those were fine, but these not?

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Is one of my "WHY" answer.

23

Looks like reached this stage.

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oh..if you refer to the middle connections, on my boards they have long , non-interrupted rails. I do have another breadboard with this interrupted long rail as well, I do know they exist. Im working on these boards for many years, they are not new anymore. Ive used them for 10's of projects ,100's even. So it's not that.
Again they are partially working ! remember that. :wink:

25

I think the only thing you have not tried is connecting them backwards.

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26

Heh, I did.
I tried on only one, on all pins configurations.
The only way it start to get hot is when I put +5V on the output pin and neg on one of its power pins.
On all other ways of connecting, stays cold. Also no normal reading either with the serial monitor.

27

I was only joking but as I have already said if you do a forum search on LM35 you will see 100's of posts with people having all kinds of problems with the LM35, some similar to what you have experienced.

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28

Thank you mister @jim-p ! This is what I wanted to hear.
Like I said, its my first time with them and I had no clue what to expect from them.
Thats why all this long discussion. Now is clear to me. I got screwed by China !

29

Old Polish saying: "buy cheap, buy twice."

30

I'd get that extra 555 out of there alltogether just in case it's playing havoc with your "external 5vsupply,) whatever it is. (Not shown) also what you connect to on the Arduino......just a blurry photo, numbering not visible.

31

Many cheap LM35 are just "rebadged" BJT, try with a transistor tester. At least, you can give them a second life...

32

I don't believe they are all damaged.
You are not doing them any favours by touching them with a soldering iron.
Select a sensible temperature like 30C (Finger heat).
Good luck.............

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