[sdiy] OT: Wisdom

[Needham, Alan]

| On 23 November 2010 11:27, Veronica Merryfield
| <veronica.merryfield at shaw.ca> wrote:
| > I wonder if the collected masses, who seem to have a decent handle on
| this sort of stuff, could take a quick look at the below ASCII art
| schematic.
| >
| > Assuming all the resistors are the same, what would the output be of the
| two op-amps?
| >
| > Thanks
| >
| > 3.3v-----
| >        |
| >        \
| >        /
| >        \
| >        /    ---/\/\/\---
| >        |   |            |
| >        |-----|+         |
| >        |     |opamp  -----
| >        \  0v-|-
| >        /
| >        \
| >        /
| >        |
| >        |
| >        |
| >        \
| >        /
| >        \
| >        /
| >        |   ---/\/\/\---
| >        |  |            |
| >         ----|+         |
| >             |opamp ------ ????
| >          0v-|-
| > _______________________________________________

All the resistors are the same,
assuming the op-amps are both reversed (as per Taku's suggestion),
Will the bottom op-amp not drive to match the + and - inputs?
3.3v through 3 resistors = 1.1v each so the bottom out will be -1.1v
The upper op-amp will be +2.2v
This gives the same current through each of the 4 'current path' resistors

Or am I missing something?
	Alan


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