Chapter 11 Troubleshooting
11-11
Output circuit troubles and corrective actions (continued).
Condition Cause Corrective actions
The load off
response time
is long.
y Over current at off state [The large solenoid current
fluidic load (L/R is large) such as is directly driven with
the transistor output.
y The off response time can be delayed by one or
more second as some loads make the current flow
across the diode at the off time of the transistor
output.
y Insert a small L/R magnetic contact and drive the load
using the same contact.
Output
transistor is
destroyed.
Surge current of the white lamp
A surge current of 10 times or more when turned on.
y To suppress the surge current make the dark current
of 1/3 to 1/5 rated current flow.
Output
E
R
Sink type transistor output
Source type transistor output
Output
Load
E
Off current
Output
Load
Output
E
R
Output
E1