Measuring Cyclic Voltammetry: What is the voltage divider for?

[CPT T]

To whom it may concern:
I was interested in knowing the reason for using a voltage divider in the multifunctional DAQ application "Measuring Cyclic Voltammetry.DOC" by A. Economou et al on the NI website.

Thank you in advance for your time and consideration in this matter.

[Dr._Imad]

Looking at the circuit, the Analog out (voltage) channel cannot deliver large currents. It is rated in few mA. The voltage divider limits the output current of the daq card to a safe value.

I looked at the attached code, the output voltage set point is divided by 0.2 (amplified) (27/104=0.2), and then it is multipied by 0.2 (the voltage divider ratio) to set it back to its original value at the OP input.

"What is the voltage divider for?" current limiting

[CPT T]

Thank you Dr. Imad. I think I understand. I have one silly question. What does the OP 90 designation for the input and output amplifier stand for?

Thank you again.

Larry

[Dr._Imad]

The triangular block in the circuit is an OP_AMP (operational amplifiier)
It needs a power supply (+9V and -9V to the -V and +V terminals (as shown in the circuit).
The other two imputs are the inverting and noninverting terminals of the OP amp. Refer to an electronics book for more information and pin configuration of the chip.

[CPT T]

Thank you for your help in this matter.