TCN75A Temp sensor investigation


Charles writes:

Upon receiving the SOIC breakout boards I took one and carefully used a Dremel to mill out the package outline. I had started to design my own PCB  but I abandoned that because I didn’t want to wait for fabrication. I mounted the new sensor on it’s vented PCB then plugged the sensors right next to each other on breadboard and put the temperature probe wedged between the boards. Obviously factors like mounting the sensor near power transistors or near your power supply are always going to have some effect on your readings, and in some cases maybe that’s what your application is meant for. I wanted to take those factors out of the equation. My workshop heating and A/C was off for over a day when I did this test… no windows where open and the chips had been prepped for about 1/2 hour on the board while I wrote the code to test them out. I decided to read data straight from the I2C bus with some confirmation on RS-232 telemetry.

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  1. From the article:
    ” Over time the un-vented sensor would measure up to .400 deg C away from the other two.”

    On my screen the “.400″ wrapped onto a new line, and the first time I read it as “400 deg C”. Please write “0.400″, “400 mK”, “four tenths”, or “400e-3″,….

  2. Interesting! Thank you for the feedback; I just noticed this got sucked up off my blog and came to look at what got linked in… I’m not sure why I didn’t include the leading zero on that figure but I’ll try to make a more conscious effort next time ;)

  3. Kevin, I thought I replied to this but I guess not. First off, thank you for the feedback! I don’t know how I didn’t get the leading 0 in there but I edited the actual article on my site. I’ve always been a bit of a lazy blogger :( I noticed DP gobbled up this blog post up when wordpress messaged me to tell me my site had an unusual amount of traffic.. happy day.

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