EGT sensors require a conditioning circuit, which can be made from discretes, but is best done with a dedicated IC such as those from Analog Devices. The following two documents contain notes on getting the most out of them.
http://www.analog.com/static/imported-f ... AN-274.pdf
http://www.analog.com/static/imported-f ... AN-369.pdf
The AD595 and friends have been replaced with the AD8495 and friends. http://www.analog.com/en/mems-sensors/a ... oduct.html
The supply voltage for these chips is raw 12V because they can handle up to 36V and because the supply doesn't affect the reading, just the range. IE, when your alternator is charging you can hit higher temperatures than when it's not. Having said that, the new device has twice the range of the old one so can hit 1000C on 5V. Thus feeding it 9V or even lower from a tiny smd regulator might be a good idea for consistency sake. On the output you just scale the voltage to 5V from your expected max with a divider and cap it with schottkys in case of a nuclear melt down in the engine bay.
These come in a SOIC8 suitable for a small project like our favourite and currently anonymous one by Dan.
Fred.
EGT Thermocouple Circuit Design Tips
EGT Thermocouple Circuit Design Tips
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Re: EGT Thermocouple Circuit Design Tips
anonymous? LOL
I like them. Skype tonight (my time) if you are free?
I like them. Skype tonight (my time) if you are free?
Re: EGT Thermocouple Circuit Design Tips
Yep, sounds good! :-)
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Re: EGT Thermocouple Circuit Design Tips
i would recommend 8 Volts.
Way to busy to do the research for you.
However All systems i work with went to 8Volts a LONG time now. Motec, pectel, Life racing, Tag...etc...etc...
All use 8v on egt drivers and can and a bunch of other things.
Said it is the highest they could go without problems if the charging system stops..
Way to busy to do the research for you.
However All systems i work with went to 8Volts a LONG time now. Motec, pectel, Life racing, Tag...etc...etc...
All use 8v on egt drivers and can and a bunch of other things.
Said it is the highest they could go without problems if the charging system stops..
Re: EGT Thermocouple Circuit Design Tips
Yep, I'd agree with that, however the correct/desirable voltage is completely dependent on the IC in use, and they all vary. So as a general recommendation, it's completely meaningless. In the case of this IC, 5V gives up to 1000C, which is usually enough. 8V would give 1600C at which point your engine is a puddle of metal on the road :-)
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- LQFP112 - Up with the play
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Re: EGT Thermocouple Circuit Design Tips
Is a digital IC a better option then?
http://www.maxim-ic.com/datasheet/index.mvp/id/7273
http://www.maxim-ic.com/datasheet/index.mvp/id/7273
Re: EGT Thermocouple Circuit Design Tips
Not necessary 1000C = 1832 °F = well above normal anyway.
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Re: EGT Thermocouple Circuit Design Tips
with the ALS and EGR on in the Group B car we have logged 1320deg :S
Re: EGT Thermocouple Circuit Design Tips
Fair enough! :-)
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Re: EGT Thermocouple Circuit Design Tips
Wait, F or C ?
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