Limit Switch; Measuring Signal Output - HBM MC3 Bedienungsanleitung

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4.5 Limit switch

Adjustment range: 0 V ... + 5 V.
The switching point of the limit switch is set within the range of 0 V ... + 5 V
using P 24. In order to define the switching point a resistor of > 500 Ohms
with reference to supply voltage terminal 22/9 should be connected to the limit
switch output (open collector) terminal 22/7. The adjustment can also be car-
ried out via the connected indicator.
The maximum voltage of + 5 V should be set by turning P 24 clockwise (to
stop). In order to determine the voltage at which the transistor switches, the
amplifier should be detuned with P 21 until the desired voltage appears at the
output.
This should be carried out within the measuring range 0.2 mV/V; if necessary,
the resistance value needs to be reduced by unsoldering R26/1 and soldering
R26 in (value is to be determined empirically).
P 24 should then be turned slowly anticlockwise until the voltage at terminal
22/7 drops to about 0.2 V residual voltage. This is the switching point
In order to avoid "fluttering" around the switching point, the tripping point is lo-
wer than the set switching point by the hysteresis voltage of 25 mV.
The hysteresis voltage can be increased by unsoldering R58/1 and soldering
R58, with a smaller resistance value, in. The value is to be determined empi-
rically.
Works setting 25 mV = 10 megohms; resistance value is inversely propor-
tional to the hysteresis voltage.

4.6 Measuring signal output

Switch S 22 must be in position 1 (circle visible). Only if the MC3 is equipped
with the final stage for current output can S 22 be used to select the desired
mode of operation.
Position 1 (circle visible) = voltage output
Position 2 (circle obscured) = current output
*)
Another possible way of setting the switching point is as follows: Connect a digital voltmeter to
measuring point 10 (see wiring diagram) and set the reference voltage with P 24.
HBM
MC3
*)
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A1705−3.2 en/de/fr