Eric

Thank you very much, I have have a look at this as soon as I return.
Do you know of any better teaching material on this subject that someone as thick as me could understand? I really need to get to grips with this stuff as my future career may depend on it!

Rupert

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"A lie gets halfway around the world before the truth has a chance to get its pants on" - Sir Winston Churchill (1874 - 1965)

 

hi,
Look thru these links.

For general purpose use of opa's, the simple formula for gain will cover most circuits.

Inv Gain: Vout = - Vin * [Rfeedback/Rinput]; note sign

Non Inv Gain: Vout = Vin * ([Rfeedback/Rinput] +1)

For GP use, a Rinput value of 1K thru 10K is often used.

To create a fixed dc offset voltage in the Vout, apply a dc voltage of the required polarity and magnitude to either the NI or INV inputs.

Basic Op Amp Design

Op Amp Building Blocks

Opamp Design

Solving simultaneous equations : ALGEBRA REFERENCE

__________________
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/

 

Eric

What can I say - THANK YOU SO MUCH!!!
I have have a good read this morning and based on the pH probe question of the forum came up with this - it may not be the best in the world but it's the first one I have ever got correct (maybe)!



Rupert

Attached Thumbnails

 

__________________
"A lie gets halfway around the world before the truth has a chance to get its pants on" - Sir Winston Churchill (1874 - 1965)

 

hi,
It looks OK at first glance, please post your *.asc file for LTspice.

__________________
Eric " Good enough is Perfect "
I will NOT answer PM's requesting technical help, please use the Forum
PIC tutorials: Nigel's www.winpicprog.co.uk/ Bill's: www.blueroomelectronics.com/