| ??? 03/21/07 09:30 Read: times |
#135480 - Eh??? Responding to: ???'s previous message |
George Micgy said:
THe math type Vrms=Vp-p/2sqrt(2) it doesn't fits to my ocassion probably Eh?? That is the equation to calculate the RMS value of a sinewave given its peak-to-peak amplitude. How can it not fit your application - unless you don't actually have a sinewave? I sample one sine wave i get from the A/D a value how can i convert that so i get a value e.g of 230 Volts The output values from you A/D range from zero to full scale[1] - so you just have to apply a suitable scaling factor The principle is exactly the same as if you had a moving-coil analogue meter with no marking on the scale - think about how you would approach that one... Remember: the A/D output is an instantaneous sample of the input voltage - if you want to measure the peak, you need to ensure that you take your measurement at the peak... [1] Or, perhaps from -(full scale) to +(full scale) |
| Topic | Author | Date |
| Calculate Rms voltage | 01/01/70 00:00 | |
| Eh??? | 01/01/70 00:00 | |
| Calculate Rms voltage | 01/01/70 00:00 | |
| Measuring RMS | 01/01/70 00:00 | |
Watch for noise | 01/01/70 00:00 | |
| The fundamental question: | 01/01/70 00:00 | |
| Calculate Rms voltage | 01/01/70 00:00 | |
| Scope | 01/01/70 00:00 | |
| Calculate Rms voltage | 01/01/70 00:00 | |
| integers? | 01/01/70 00:00 | |
| Calculating RMS | 01/01/70 00:00 |