| ??? 04/23/11 11:40 Read: times |
#181985 - Answers Responding to: ???'s previous message |
Kai said:
Your scope plot shows interference in the 100Hz range. This would mean a huge time constant for the low pass filter. >1mH + >1000µF could do the trick. But there would be needed some series resistance (1...2R) to dampen the resonance of this filter, otherwise you will get huge destroying voltage spikes when connecting the 12V to your scheme. So, not a non-ohmic solution...
I think, filtering alone is no option here. Kai Klaas Thanks for that suggestion ,I tried the filter below but unfortunately no effect . The digital servo looks too notorious.The inductor was a toroid core type.
+12V--------L(4mH)----R(2.2E)----- to display
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C (1000uF)
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GND
I answer Erik's questions poin wiz below; Erik said:
1) the waveform of what? Erik Its AC coupled noise on the DC line Erik said:
2) what is the ground reference Erik -ve terminal of the battery Erik said:
3) is 20mV rally 200mV (10x probe) Erik No it was at 1x therefore I didnt mention Erik said:
4) can your scope do differential (a+b, b inverted)? Erik I will check that with a DSO Erik -Ap |
| Topic | Author | Date |
| Noise originating from servomotor | 01/01/70 00:00 | |
| Filters | 01/01/70 00:00 | |
| filters | 01/01/70 00:00 | |
| 3 wires servo | 01/01/70 00:00 | |
| Use two different supplies | 01/01/70 00:00 | |
| may sound silly, but | 01/01/70 00:00 | |
| further noise analysis | 01/01/70 00:00 | |
| Filtering is no option here... | 01/01/70 00:00 | |
| questions | 01/01/70 00:00 | |
| Answers | 01/01/70 00:00 | |
| my experience is ... | 01/01/70 00:00 | |
| Couldnt find much difference | 01/01/70 00:00 | |
| Ground impedance? | 01/01/70 00:00 | |
| One last bit of information that may help... | 01/01/70 00:00 | |
what we do | 01/01/70 00:00 |