| ??? 10/07/08 17:24 Read: times |
#158909 - LVDT driving Responding to: ???'s previous message |
Ap Charles said:
I dont have experience with wein bridge oscillator with op amps. Any recommendations schematics/ site ,I need high amplitude stability as I am going to excite an RVDT . We have precision, very low distortion oscillators for exactly that application Ap, I can send you some circuit diagrams. We measure the CURRENT in the LVDT, which is a more accurate method of stabilising the reference levels than a voltage. Our favourite method uses a Colpitts oscillator as the signal source. That needs a tiny transformer, but you can use any oscillator topology you like, provided you can readily control its amplitude. If you use a DDS chip, you still need to get precision amplitude, so you could feed a dds with a reference, and use the same reference for the A/D circuits after the demodulation. Steve |
| Topic | Author | Date |
| Function Generator IC | 01/01/70 00:00 | |
| Better? | 01/01/70 00:00 | |
| Maxim | 01/01/70 00:00 | |
| Maxim unavailable | 01/01/70 00:00 | |
| DDS? | 01/01/70 00:00 | |
| Better? .5% -1% THD with discrete solution? | 01/01/70 00:00 | |
| Wein bridge? | 01/01/70 00:00 | |
| Simple wont do ... | 01/01/70 00:00 | |
| LVDT driving | 01/01/70 00:00 | |
| High performance can be simple | 01/01/70 00:00 | |
| Tuning | 01/01/70 00:00 | |
| DDS again | 01/01/70 00:00 | |
| Design. | 01/01/70 00:00 | |
| What frequency? | 01/01/70 00:00 | |
| frequency | 01/01/70 00:00 | |
| Err | 01/01/70 00:00 | |
| DDS again | 01/01/70 00:00 | |
| THD | 01/01/70 00:00 | |
| THD | 01/01/70 00:00 | |
| reference | 01/01/70 00:00 | |
| Yes, but at what cost? | 01/01/70 00:00 | |
| About 4 bucks | 01/01/70 00:00 | |
| Better? In what way? | 01/01/70 00:00 | |
| 6 dollars | 01/01/70 00:00 | |
| Gee ... That isn't so bad! | 01/01/70 00:00 | |
| Tuning | 01/01/70 00:00 | |
| Hand-tuning is not cheap! | 01/01/70 00:00 | |
| Drift | 01/01/70 00:00 | |
| how does drift impact the manpower requirement? | 01/01/70 00:00 | |
| Notes | 01/01/70 00:00 | |
| Amplitude , tempco | 01/01/70 00:00 | |
| Precision | 01/01/70 00:00 | |
| Precision ... | 01/01/70 00:00 | |
| at that rate | 01/01/70 00:00 | |
| to Steve | 01/01/70 00:00 | |
| LVDT | 01/01/70 00:00 | |
| power/energy meter IC | 01/01/70 00:00 | |
energy meter IC | 01/01/70 00:00 | |
| at that rate | 01/01/70 00:00 | |
| Filtering? | 01/01/70 00:00 | |
| It will remove SOME of the distortion | 01/01/70 00:00 | |
| have you seen this? | 01/01/70 00:00 | |
| I am afraid | 01/01/70 00:00 | |
| Simple` | 01/01/70 00:00 | |
| DTMF Genarator | 01/01/70 00:00 |