Section 2
– Operation
TOELLNER Electronic Instrumente GmbH
13
the feeding source to the input socket pair
Plus
– Minus
, this maximum frequency may
however not be reached, but rather the
TOE 9261
will shut off at even a significantly lower
frequency due to overload, which is indicated by the
OVL
LED.
The reason for this overload in this case will be the inductive energy from the incoming line,
which continues to flow into the
TOE 9261
for each turn-off event in the longitudinal path and
which is converted as a product factor of the switching frequency into power loss.
The following measures must be taken to increase the achievable switching frequency:
Minimize the cable length to the input socket pair
Plus
– Minus
Parallel, closely adjacent routing of both cable conductors
Use of a feed source with high output buffer capacity
Applying the input buffer capacitor of the
TOE 9261
by setting the DIL switch
INPUT C / ON
to
ON
. The built-in capacitor is thermally protected against too high ripple
current load which may be caused by high consumer currents at high PWM switching
frequencies.
Warning
Consumers which are not expressly approved for PWM operation may not be turned on
and off at high switching frequencies, since otherwise buffer stages in the consumer, e.g.
electrolytic capacitors, can overheat and be damaged by excessive ripple current loads!
2.5
Operation of the signal line switches
2.5.1
Connection
To switch signal lines, they are routed through the bidirectional switches
S3
– S6
. They are
connected using the correspondingly labeled front panel connectors. These can be used with
suitable terminal block plugs (
4.1 Technical data TOE 9261, Connections, Signal line
switches)
S3
– S6
provide four bidirectional signal line switches, for example to be able to turn on or
interrupt a multi-pole signal connection simultaneously. The terminals for unneeded signal
line switches are left unconnected.
The direction of current flow through the signal line switches
S3
– S6
can be selected as
desired and independent of each other.
The upper limit of the applied signal levels is limited to the rated voltage of the
TOE 9261
.
The electrical isolation between the signal line switches and to the
CONTROL
input is for up
to 42 V
peak
.
2.5.2
Control
Closing and opening the signal line switches
S3
– S6
takes place synchronous with each
other as well as synchronous with closing and opening of the longitudinal path
S1
of the
power switch. The signal line switches are controlled further even if the longitudinal path
S1
is disabled per DIL switch
S1 ENABLE
in the
OFF
position.
The functions and possible uses of the
CONTROL
input are the same as described for the
power switch (
2.4.7 Control of switching paths and operation of the consumer) except for
the information which explicitly refers to operation of a load via the paths
S1
and
S2
.
