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View Poll Results: Preferred display for Brake Temp Monitor ?
Analog gauge x4 1 16.67%
LEDs (BLUE:Cold, GREEN: Ok RED: Hot) 2 33.33%
LCD Numeric 3 50.00%
Voters: 6. You may not vote on this poll

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Old 02-18-2017, 08:34 PM   #31
dvallis
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It's alive!!!!!!!!!!!

Brake temp gauge is alive. Enjoy.

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Old 02-19-2017, 06:21 PM   #32
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Brake temp gauge reading and displaying analog input.

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Old 02-22-2017, 10:54 PM   #33
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Re-wrote the code with a proper stepper motor driver. Added ballistics, acceleration etc. Needle is much better behaved and moves smoother now. ADC is reading dummy data and displaying on the gauge. Ready to add thermocouple interface.

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Last edited by dvallis; 02-23-2017 at 10:30 AM. Reason: Typo
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Old 02-23-2017, 05:10 PM   #34
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Neat. The most cost effective method for finding a sensor for rotor surface temp would probably be to tear down a commercially available infrared pyrometer and either find a datasheet on the sensor or reverse engineer the unit it for signal interpretation. You'd need to make a custom housing with an IR-transparent lens though, might be prohibitive if you don't have machine tools, but even then I think it would probably be cheaper to have something turned out on a lathe and weld a bracket to it than the $600 per sensor mentioned earlier in the thread. That's if you must have rotor surface temperature, the commercially available thermocouple embedded in the brake pad is a fine solution you'd just have to account for conduction.

Quote:
Originally Posted by redlightpete View Post
IR measurements are typically inaccurate on shiny, varying surfaces like the braking surface of a disc.
That would only be an issue when something hotter is radiating IR which is bouncing off of your reflective surface, in the case of brakes where they'll be very hot and emitting a lot of IR, there would be no issue.
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Old 02-23-2017, 07:08 PM   #35
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I'm going with a 2000F thermocouple attached to each brake pad. Much simpler and more robust at the hot end than an IR thermal sensor. Thermcouple does not need cleaning like IR sensor. Downside is thermocouple requires high precision analog front end for sensing, but I know how to build that. Already have a source for bulk thermocouple raw materials so I can make my own for a fraction of retail price.
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Old Today, 11:37 AM   #36
dvallis
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Thermocouple Testing

Built a thermocouple test circuit this morning. Used a precision soldering iron to generate temperatures around 750F and measure it with PSOC. Worked perfectly. Next step is translating the thermocouple output onto the gauge. See video below.

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