| ??? 08/21/07 20:22 Read: times |
#143468 - Unsafe? Responding to: ???'s previous message |
M Chitrakar said:
... a voltage divider and directly read into a ADC and then to the microcontroller. Obviously, it is unsafe. I'm sorry, but it is not at all "obvious" that this is unsafe. I have several multimeters here and they are all capable of measuring DC voltages up to 1000V, with perfect safety. Yet, they contain nothing more elaborate than a voltage divider and some overvoltage protection. No need for any isolation whatsoever. That is, until you want to connect them to a PC (trough IEEE-488 or RS-232). Then you need isolation, in order to avoid dangerous situations. But unless the source of the DC voltage you need to measure has a direct connection with the mains, you really don't need anything other than a voltage divider. If you really do need isolation, you might consider an isolation amplifier Rob. |
