Team E Meeting Minutes

Wednesday, October 29, 1999

Deanís Office

Conference Call with Lee Payne


In Attendance:

Scott Hancock, Vishal Golia, Greg Sitrick, and Donnie Yazzie.


1.                  Need instrument bridge to reject common mode, for the x100 gain.

2.                  Will be much noise with the suggested model we had developed.

3.                  Lee suggests using the ADC.

4.                  Three op amps and resistors for the differential amplifier.

5.                  We have a known input calibration to use (about 0-10V).

6.                  10.24V scales to even bits on an ADC.Not critical.

7.                  12-bit ADC, 10V range at a minimum.

8.                  12 bits or more on digital communications to port to host.

9.                  Signals from the host to the system go to DAC and PGA.

10.              When there is no strain, we need to zero the output.We will adjust the PGA and DAC for this.

11.              We will check with Microchip for development software.Lee will pay for one if Microchip will not provide one for free.

12.              Lee will check with his guys for a development platform.

13.              Set PGA to 1 to start.Then increment to get best resolution.Will have gone too far if the ADC is saturated.

14.              In the strain gauge simulation circuit, we could make the top two resistors larger to attenuate the signal or lesson to get more signal.

15.              Control loops will be one to zero the DAC and another to adjust the PGA for best resolution.

16.              Lee could write up more information upon the request of the Team E members.