View Full Version : Max 6675 Fluctuation values When using IOs on pic876

- 13th June 2011, 19:56
Hi all,
here is a triky situation,
on a Pic 16F876,
When using a digital Out pin to toggle an ON/OFF relay via a mosfet transistor (10K on Gate)
the conversion of the (SPI) Max6675 ofset the Temp value to +8c, Why is that?:(

is there any solution to this?
The max6675 has a super stable 5V PS.

- 14th June 2011, 02:28
and the relay use the same psu rail?

Would be great to see your code & schematic....

- 14th June 2011, 15:10
Thanks Steve,
I have a 24vdc/9A and 5/6A vdc power supply.
I tryed all day to separate the PS of the relays by using regulator in series from 24v to 15v to 5v regulator to power the relays but same thing happened!.
I have 6x 5v relays 4 analog pot, 4X servos, one pressur sensor (analog in), and one Max6675(3 i/o) on the Pic876.
also the analog values are Ofsetting when the digital out are ON, the value on the TC is adding as the outputs are ON
today I am going to try to split all the digital I/O's to a second pic.