Help choosing an instrumentation amplifier for k type thermocouple

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Hey guys i have unsuccessfully tried to amplify a k-type thermocouple signal using an op amp as a non inverting amplifier. i have been reading and researching and it seams quite involved to amplify such a small signal. I would like to ask you guys for advice on what instrumentation amplifier chip i can buy to amplify the signal. preferable the cheapest option i can get as i don't have much money.

 

 

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Look at the LTC1049 datasheet, it has an example for a k-type thermocouple.

 

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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https://learn.adafruit.com/thermocouple/using-a-thermocouple

Using one of those Maxim chips will make your task easier. Seems you can get some cheap boards out of China.
http://ww1.microchip.com/downloads/en/AppNotes/00844a.pdf
Here's an app note from the evil overlords.

Last Edited: Fri. Feb 5, 2016 - 07:07 AM
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One of the older industry standard thermocouple amplifiers is this one.

 

http://www.ebay.com/itm/MAX6675-...

 

The more modern one is this one.

 

http://www.ebay.com.au/itm/MAX31...

 

Cheers,

 

Ross

Ross McKenzie ValuSoft Melbourne Australia

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Here's an app note from the evil overlords.

Insect.  >>Insect<< overlords :)

"Experience is what enables you to recognise a mistake the second time you make it."

"Good judgement comes from experience.  Experience comes from bad judgement."

"Wisdom is always wont to arrive late, and to be a little approximate on first possession."

"When you hear hoofbeats, think horses, not unicorns."

"Fast.  Cheap.  Good.  Pick two."

"We see a lot of arses on handlebars around here." - [J Ekdahl]

 

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I have used MCP6V07. it's magnificent!

A rail to rail I/O auto-zero Op-Amp and other great features that you can see. e.g. it's cheaper than LTC1049 and one of those module which Ross suggested. supply 1.8-5.5v! and etc.

 

"One's value is inherent; money is not inherent"

 

Chuck, you are in my heart!

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Salaam Amin.

 

Is your MCP6V07 mounted on a module and still cheaper than the lowest of my two links?

 

Ross McKenzie ValuSoft Melbourne Australia

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valusoft wrote:

Salaam Amin.

 

Is your MCP6V07 mounted on a module and still cheaper than the lowest of my two links?

 

Salam Ross

I don't know. but that's fishy to me Ross. How could a MAX6675 module+ a thermocouple be lower than $4?

Can you find a MAX6675 even around $4?

"One's value is inherent; money is not inherent"

 

Chuck, you are in my heart!

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Well it isn't fishy... I have one of each. Possibly a knock-off, but it works OK.

 

Ross McKenzie ValuSoft Melbourne Australia