Trimmer position

[bee]

eric
I only ran the transistor setup in spice and it wasnt to bad,Its better in the circuit than it was
i will keep thinking about this maybe get another ad623 or do they come in dual package?
I will search around
cheers
bee

 

[ericgibbs]

eric
I only ran the transistor setup in spice and it wasnt to bad,Its better in the circuit than it was
i will keep thinking about this maybe get another ad623 or do they come in dual package?
I will search around
cheers
bee

You dont need another AD623 OPA, a regular MCP rail to rail will be OK.

 

[bee]

Eric

I have set this up today and it works well,The amp i used is a dual one that i had in stock
I also raised the gain of the ad623 to 1000 not sure if i should drop this and raise the mcp6292 for stability
Also were did you get the ad623 pattern for spice

thanks
bee

 

[ericgibbs]

Eric

I have set this up today and it works well,The amp i used is a dual one that i had in stock
I also raised the gain of the ad623 to 1000 not sure if i should drop this and raise the mcp6292 for stability
Also were did you get the ad623 pattern for spice

thanks
bee

hi,
Thats good news.
I would set the AD623 to *500 and double gain of the output OPA.
If you make the R4 resistor a 50Kpot you can set the SPAN to suit your project. [if not a 47K should give about double the gain]

I made a LTSpice hierarchical circuit for my version of the AD623

 

[bee]

eric
I have changed the 22k for a 47k on the output amp,And dropped the gain on the ad623 to 500 and all is good
Just have to build this on another board and test again in the real world

Thanks for your help on this one
bee