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TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch
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TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by loonhaunt on Sun Nov 28, 2021 1:55 pm

Just a quick question regarding a TMP 36. Do they normally get super hot to the touch. I have one wired to a MCP 3002 by way of a tutorial , connected to 3.3v on a raspberry pi. It is a non-Adafruit tutorial. I really only need to know how hot they should be to touch, I have used the before and don't remember this phenomena?

Thanks

Loon

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Re: TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by franklin97355 on Sun Nov 28, 2021 3:18 pm

I wouldn't think a "Temperature" sensor should get internally hot but it sounds like a miswiring. Can you post a circuit diagram of your connection or, better yet, a photo?

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Re: TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by loonhaunt on Tue Nov 30, 2021 8:28 am

PXL_20211130_121841859_2.jpg
PXL_20211130_121841859_2.jpg (499.13 KiB) Viewed 124 times


I followed this schematic exactly. (Minus the LCD) I thought that the MCP3002 could be sucking more current through the TMP36 GZ, so I then wired up the TMP36GZ with it's own power and ground 3.3v and still got so hot I had to use a plier to pull it off the breadboard. I have used these sensors in lot's of other applications and never had this issue. I am not what the GZ extension means after the TMP36? I bought a batch of ten of these off Amazon, I have tested three of them and they have all overheated. I would send a picture of my breadboard but it is pretty hard to follow as the jumpers I used are quite long.

Thanks for your attention

Dave

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Re: TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by adafruit_support_bill on Tue Nov 30, 2021 9:11 am

A TMP36 normally consumes about 50uA. Any self heating should be less than less than 0.1°C. Not sure what the 'GZ' in the part name is for. It is possible that the devices you purchased on Amazon have a different pinout.

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Re: TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by loonhaunt on Tue Nov 30, 2021 12:04 pm

I am not sure about the GZ either. I tried them by flip flopping the power and ground while measuring the voltage. I had the pin outs correct I am going to look up the part number when I have time. In the meantime I am going to order some TMP 36's from Adafruit. Found specs for the GZ's online they look the same as what I have been using previously??

Thanks.

Dave

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Re: TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by loonhaunt on Tue Nov 30, 2021 12:08 pm

Just looked at the image of Adafruit listed TMP36,,,it also had the GZ extension at the end. Maybe I got a bad batch??

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Re: TMP 36 Rpi MCP 3002 TMP = Blazing hot to touch

by adafruit_support_bill on Tue Nov 30, 2021 12:42 pm

Could be a bad batch or maybe some mismarked clones.

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Please be positive and constructive with your questions and comments.