reference post:
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3 - The mA signal is passed through a 250 Ohm resistor to produce a
1-5 V signal for the op amps. Thus there is a minimum of 1 watt power consumption. This is sufficient to exceed most sources of interference.
Walter.
sorry walter for this ghost query, but i fail to understand why a 4 to
20 mA current flowing through 250 ohm, would waste 1000mW 'minimum'. if power consumption is I.R and not I*I.R, i need your tution. i figure the power wasted across resistor as 4mW(4*4*millie*millie*250) to 100mW(20*20*millie*millie*250) please correct wrongness in my understanding.
D'jay