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Topic: is it possible to amplify a 0 - 55 mV current? (Read 2 times) previous topic - next topic


3z33


Ask uncle google!
http://www.google.com/search?q=amplifying%20thermocouple%20arduino


when you want to pull the google card, two pointers:

1.  Use http://lmgtfy.com/  , it's way cooler.
2.  Actually google it yourself and review the results.  In this case, the first result returned is actually this thread so...... :~

Jack Christensen


(I know they sell purpose built amp ICs to do this, but they are $12 per chip.  I'd like to try to do it with a less expensive per unit item like an op amp...but I have no idea which one would work.)


These work quite well for me.  $17.50 > $12.00, I know ;).  But well worth it IMHO.  Gets out of the analog realm, no conversion table to take up memory space, built-in cold junction compensation.  But if you're dead set against it, or just in it for the academic exercise I might try an LF353.  Nice high input impedance so as not to load the thermocouple and < $0.50 in single quantities.  Actually I'd want to research the proper way to interface to the thermocouple, there may be a standard input impedance that may need to be provided with a resistor or other considerations, I have no idea, which was another reason I went with the MAX6675.  If you do try that route, I have a simple little library, not much to it, but nice for multiple TCs.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

brucethehoon



Ask uncle google!
http://www.google.com/search?q=amplifying%20thermocouple%20arduino


when you want to pull the google card, two pointers:

1.  Use http://lmgtfy.com/  , it's way cooler.
2.  Actually google it yourself and review the results.  In this case, the first result returned is actually this thread so...... :~


I find that lmgtfy is smart assy and I really intended to just show that when you know the right search term, it makes things easier.

Next, THIS was not the first result.   The first result was your double post in which you "got no answers" including a non answer or three from Grumpy Mike.   Now, it's not just that I'm afraid of him, but I tend to listen pretty carefully when he fails to answer my questions - especially at such length.

Should your attention span carry on down the search results, you will find exactly what you're asking for.  I wish you luck!

bubulindo


sorry about the current/voltage mistake...I'm new to electronics.  I'm 90/10 programmer/electronics relative to arduino.


We are all learning. The fact is that if you know (and understand) the correct definition, finding what information you need regarding it becomes way easier. 
Eu não sou o teu criado. Se respondo no fórum é para ajudar todos mediante a minha disponibilidade e disposição. Responder por mensagem pessoal iria contra o propósito do fórum e por isso evito-o.
Se realmente pretendes que eu te ajude por mensagem pessoal, então podemos chegar a um acordo e contrato onde me pagas pela ajuda que eu fornecer e poderás então definir os termos de confidencialidade do meu serviço. De forma contrária toda e qualquer ajuda que eu der tem de ser visível a todos os participantes do fórum (será boa ideia, veres o significado da palavra fórum).
Nota também que eu não me responsabilizo por parvoíces escritas neste espaço pelo que se vais seguir algo dito por mim, entende que o farás por tua conta e risco.

Dito isto, mensagens pessoais só se forem pessoais, ou seja, se já interagimos de alguma forma no passado ou se me pretendes convidar para uma churrascada com cerveja (paga por ti, obviamente).

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