Rockwell Automation 1769-OB16 Compact Solid State 24V dc Source Output Module - Manual (Page 17)

Compact™ Solid State 24V dc Source Output Module 17
Publication 1769-IN054A-EN-P - April 2001
Transistor Output Transient Pulses
The maximum duration of the transient pulse occurs when minimum load is
connected to the output. However, for most applications, the energy of the
transient pulse is not sufficient to energize the load.
The graph below illustrates that the duration of the transient is proportional to the
load current. Therefore, as the on-state load current increases, the transient pulse
decreases. Power-up transients do not exceed the time duration shown below, for
the amount of loading indicated, at 60°C (140°F).
ATTENTION
!
A transient pulse occurs in transistor outputs when the external
DC supply voltage is applied to the output common terminals
(e.g. via the master control relay). The sudden application of
voltage creates this transient pulse. This condition is inherent in
transistor outputs and is common to solid state devices. A
transient pulse can occur regardless of the controller having
power or not. Refer to your controller’s user manual to reduce
inadvertent operation.
0.4
1.0
0.9
0.8
0.7
0.6
0.5
0.3
0.2
0.1
0.0
1000 900 800 700 600 500 400 300 200 100 1
On-State Load Current (mA)
Ti
me -
D
ur
at
ion of
T
ran
sient
(ms
)
Transient Pulse Duration as a Function of Load Current