338
Precautions When Connecting Two-wire DC Sensors Appendix E
Relationship between a DC Input-type Communications Unit’s
OFF Current and a Sensor’s Leakage Current
I
OFF
≥ I
leak
I
OUT
: OFF current of a Communications Unit with DC Inputs
I
leak
: Sensor's leakage current
Connect a bleeder resistor if I
leak
is greater than I
OFF
.
The bleeder resistor constant can be calculated using the following equation.
R ≤ (I
OFF
× R
IN
+ V
F
)/(I
leak
− V
OFF
)
Power W ≥ (V
CC
− V
R
)
2
/R × 4 [allowable margin]
To Next Page
Loading...
