| ??? 04/28/11 15:36 Read: times |
#182084 - Zero crossing without precision rectifier |
While measuring Mains voltages, using a rectifier at the input distorts the waveform and also makes it necessary to tune the results using a standard meter like Fluke. To avoid using additional components, many a times, ac wave (after sampling transformer) is directly fed to the ADC pin after a resistive divider. I have seen this used in PIC/AVR/Freescale based designs. When the voltage goes negative, the diodes at the input clamp the voltage. Only the positive half is sampled since it is assumed that negative half would match the positive half, for almost all kinds of loads.
How safe is this method? |
| Topic | Author | Date |
| Zero crossing without precision rectifier | 01/01/70 00:00 | |
| read the datasheet | 01/01/70 00:00 | |
| Inserting a DC component | 01/01/70 00:00 | |
| ??? | 01/01/70 00:00 | |
| Explanation | 01/01/70 00:00 | |
| No need to align with any zero axis | 01/01/70 00:00 | |
| Great | 01/01/70 00:00 | |
| Are you sure your current/voltages are sine waves? | 01/01/70 00:00 | |
no sinusodal currents | 01/01/70 00:00 |