Mesa MQC 0506, Operating Manual

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MESA Automation GmbH
MQC 05 V 3 EM 7
5.4 Armature Current Measurement
Armature current is measured by means of a shunt placed in series with the armature circuit. The voltage
produced can be measured at the „I Monitor“ test point. 10 Volts output corresponds to the maximum current
of the amplifier.
Max. Output current I
Amax
: P4
The amplifier is capable of supplying twice is rated current for 1.5-5 seconds. Peak current will be adjusted by
P4.
Standard-Range: Right side: I
Amax
= 1 x I
max
= Type-max. current
Left side: I
Amax
= 0,03 x I
max
Current balance: P7
Adjustment of the internal Current measurement! Set by factory, do not change !
5.5 RMS - Function I
Arms
Momentary current is processed into an I rms. Value by a squarer network and is negatively feed back to the
armature current control point via a threshold value switch. The I rms. Current is adjusted with P5 and is
maintained irrespective of the curve shape of the armature current actual value.
I
I
Amax
t
1
= acceleration pick-up
I
Arms
t
2
= limitation
τ
= t
2
-t
1
(without pre charge)
t
1
t
2
t
RMS output current I
Arms
: P5
Follow the procedure given above for adjustment of I
Amax
. The I
Arms
pot P 5 can be adjusted and is value read
from the monitor after about 5 seconds.
Standard-
Range
Right side: I
Arms
= 1 x I
Nrms
= Type rated current
Left side: I
Arms
= 0,1 x I
Nrms
5.6 BEMF feedback Speed control with I x R-compensation
Application without Tacho feedback are possible with lower accuracy of the speed controller
the use of an compensation resistor R12 gives an increase of accuracy.
Attention:
Solder jumper Br1, Br2 close for BEMF operation, in this case BR 3 must be open !
For amplifiers with more then 60 V output voltage never close direct BR1 + Br2 use two additional resistors
R
V
(R211/212)