| ??? 01/21/10 10:34 Modified: 01/21/10 10:36 Read: times |
#172635 - modulating the excitation Responding to: ???'s previous message |
Kai Klaas said:
Yes, of course. But again, the precision of these voltage dividers must be extremely high and the temp drift and long-term drift extremely low. Ap, why don't you modulate the excitation voltage of the bridge by a AC signal? Then, you wouldn't need to battle with this annoyingly high DC offset voltage. Kai Klaas Kai , I did that stuff in the past but in the end I had to resort to AD598 for RVDT conditioning :). I explore 0.1% 25ppm resistors to be ok(0.4$/part from KOA speer) do you recommend other resistors? I can source from Taiwan 5ppm parts.For our info The sensor accuracy is 0.25%FS with 0.025%FS/C as span coeff . stephan, Ti part you suggested fully fits the problem , will check this if discrete alternative fails . Thanks/ -Ap |
| Topic | Author | Date |
| Isolating xducer | 01/01/70 00:00 | |
| not even a way | 01/01/70 00:00 | |
| noise | 01/01/70 00:00 | |
| I wouldn't do that... | 01/01/70 00:00 | |
| agree | 01/01/70 00:00 | |
| when within specified range!!! | 01/01/70 00:00 | |
| why 8V or 20V | 01/01/70 00:00 | |
| no specs violated | 01/01/70 00:00 | |
| that is TOTALLY irrelevant | 01/01/70 00:00 | |
| Jumping to conclusions | 01/01/70 00:00 | |
| AC modulating the bridge excitation voltage? | 01/01/70 00:00 | |
modulating the excitation | 01/01/70 00:00 | |
| make it simple at start | 01/01/70 00:00 | |
| making it | 01/01/70 00:00 | |
| o, i see... | 01/01/70 00:00 | |
| from my experience with loadcells ... | 01/01/70 00:00 | |
| what is exactly "xducer" ? | 01/01/70 00:00 | |
| Offsetting a signal | 01/01/70 00:00 | |
| Yes but...? | 01/01/70 00:00 | |
| Error analysis and budget | 01/01/70 00:00 | |
| Common Mode suppression | 01/01/70 00:00 |