thermocouples

H

Hubsy

New Member
I've read that,

'The picaxe is setup for Type K thermcouples'

but I can't find how.


I've searched all 3 manuals but can't locate the info.

using an 18M chip on pin 17, ADC 0

any pointers please ?

hubs
 
hippy

hippy

Ex-Staff (retired)
Where did you read that ?

Analogue input on a PICAXE is never setup for any particular configuration, it simply reads whatever it finds on its ADC pin.
 
hippy

hippy

Ex-Staff (retired)
From that thread and a quick forum search it appears you are likely to be needing a MAX6674 or MAX6675 to do the interfacing.

Search criteria of "MAX6674", "MAX6675" and "thermocouple" should bring up more useful information.
 
B

BeanieBots

Moderator
A thermocouple produces a very small voltage per degree at EVERY junction.
That INCLUDES the connections to its leads.

For this reason, a SPECIAL type of amplifier (thermocouple amplifier) is required. There are many different types, of which two are mentioned above.

They amplify the signal to a voltage large enough to be read by a PICAXE but just as importantly, they compensate for the voltages which are also generated at the connections. (cold junction compensation).

It is NOT possible to connect a thermocouple direct to a PICAXE and be able to read anything.
 
H

Hubsy

New Member
Anyone know a UK supplier for the MAX6675 chip please?

My usual suppliers have let me down this time.
 
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