Toshiba SX 2000 - Manual (Page 136)

(5) If a capacitive load is connected, rush current will flow when output is
charged to ON.
At that time, necessary measures must be taken to protect the output
transistor from being destroyed by the rush current.
To limit the rush current there are two effective measures. One is to
connect a resistor to the load in series. The other is to apply dummy
current to the load by connecting a resistor between the output terminals.
(6) If an inductive load is connected, transient overvoltage will occur when the
output is changed to OFF.
This surge voltage will be absorbed into the diode D mentioned before so that
the transistor will be protected. Flowever, if the output cable is installed closely
to other signal lines, the surge voltage may cause other problem. In this case,
install a flywheel diode in parallel with the inductive load (as near as possible
to the load).
3.3 Precautions for DC Output Modules
Transistor
Output
module
A suitable surge absorption element should be selected according to the
application.
® Flywheel diode °H° Peak inverse voltage:
(for voltage 3 times the power supply
clamping) voltage or more
Forward current:
Load current or more
Varistor
(for voltage
clamping)
Rated voltage about
twice the maximum(peak)
power supply or more
Snubber(CR)
voltage circuit
(for high frequency
attenuation)
H PW—o R: 0.5 - pert V coil voltage
C: 0.5 - 1pF per 1A coil current
(Non-polar capacitor)
6F8C0926 1 1 9