Toshiba 6F3B0253 User Manual
Page 51
6F3B0253
Basic Hardware and Function
49
3. I/O Application Precautions
(4) Countermeasures against leakage current
When a switch with an LED or sensor is used, the input sometimes cannot recognize
that the switch is off due to the current leakage. In this case, install a bleeder resistor
to reduce input impedance.
Select a bleeder resistor according to the following criteria:
(a) The voltage between the input terminals must be lower than the OFF voltage
when the sensor is switched off.
(b) The current must be within the allowable range when the sensor is switched on.
(c) Calculate the wattage of the bleeder resistor by multiplying the current when the
sensor is switched on times three.
T1
input
circuit
Bleeder resistor
LE
C