??? 06/06/10 16:55 Read: times |
#176450 - I think I see what is needed Responding to: ???'s previous message |
Per Westermark said:
So you may supply 9V and must support up to 20mA. Or you may supply 20V up to 20mA. Or all the way to 32V up to 20mA. Obviously, the amount of power needed from your USB connector will increase if you select a higher voltage. But a higher voltage will allow a longer cable without problems with voltage loss in the cable. At 9V, you don't have any margin for voltage loss in the cable. I think that pretty sums up the answer ? And since my notebook is very close to the sensor ( less than 10m) I think I will be very safe to plan to supply 15V with a capacity to support 25mA. Raghu |