FOR TRANSISTOR-FOUR-QUADRANT SERVO-AMPLIFIER TYPE

TECHNICAL INFORMATIONEdition 1.00

FOR

TRANSISTOR-FOUR-QUADRANT

SERVO-AMPLIFIER

TYPE

MTRF 25...61/5-15

V 5.0

Telefon: +49 (0)761- 15 23 4-0Telefax: +49 (0)761- 15 23 4-56E-Mail: [email protected]://www.mattke.de

MATTKE AGLeinenweberstraße 12D-79108 FreiburgGermany

Technical information edition 1.00 MTRF 25...61/5-15 V 5.0 12.11.2003

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Dear customer,

We always try to guarantee for an optimum of security measures and to inform ourselves about the latestdevelopments in technical research. However, it is necessary that we pass on the following furtherinformation to you as the user of our components:The appliances are supply parts meant for processing by industry, trade or other factories specialised inelectronics.

Safety precaution !!

Attention - do not touch!. The appliances have unprotected live parts. The voltagemay be highly dangerous.

We also have to inform you that, for your own security, only an expert should work onthe appliances.

In order to comply with the safety precautions, open connections must be protectedagainst contact with cases, coverings or anything similar. Even after the appliance hadbeen disconnected, there may still be a dangerous voltage (discharges of thecapacitors).

Due to an error in handling or unfavourable conditions, the electrolytic capacitors mayexplode. If you have to work on the open appliance, do protect your body (hands!) andyour face!

Make sure that there is enough ventilation because of the fire risk in case ofoverheating.


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CONTENTSpage

1. Important instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2. General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3. Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4. Control principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5. Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6. Wiring and earthing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

7. Explanation of connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

7.1 Inputs7.1.1 Speed set value inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87.1.2 Current limitation input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87.2.3 Pulse encoder - tracks A and B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.3.4 Disable input, release of the final stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.4.5 Integral off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.5.6 Limit switch “positive stop” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97.6.7 Limit switch "negative stop" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107.7.8 Tacho input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7.2 Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117.2.1 Supply of the intermediary circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117.2..2 Battery supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7.3 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117.3.1 Output "ready for operation" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117.3.2 Ia monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127.3.3 Reference voltage outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127.3.4 Motor output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

8. Adjustment possibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9. Selection of the mode of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

10. Dimensioned drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

11. Initial Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

11.1 Input test circuit, tacho control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1411.2 Input test circuit, encoder control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1511.3 EMF control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1511.4 Current control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1511.5 Pre-adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1611.6 Adjustment of pulsed current and effective current . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1611.7 Offset adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1611.8 Ramp adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1611.9 Ballast circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1711.10 Connection to an external encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18


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12. Optimization of the control behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

12.1 Alternating voltage amplification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1712.2 Direct voltage amplification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1712.3 Integral part of the speed controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

13. MTRF as a follow-up amplifier MTNRF 25...61/5-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

14. Plan of components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

15. Trouble shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20


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1. IMPORTANT INSTRUCTIONS

- The amplifier should only be connected and started by experienced technicians.

- The amplifier should only be installed or removed with the supply voltage switched off.

- After switching off the amplifier, parts of the board can still be alive for about 3 minutes.

- Make sure that the intermediary circuit voltage measured at the plug-in unit between pin 22ace and 32ace cannot exceed 85 V DC even when the motor is not running.

- Please be careful when calculating the transformer secondary voltage and allow for voltage differences between no load and full load as well as mains fluctuations.

Comparison with the previous models MTRF 25...61/5-15 V 3.0 and V 4.0

The standard connections of the version 5.0 are the connections of the version 3.0. It is possible to usethe version 4.0 changing the soldering bridges.

PIN MTRF 24...60/5-15, V 3.0 MTRF 25...61/5-15, V 4.0 MTRF 25...61/5-15 V 5.0

4a GND Pulse encoder, track A GND / opt. track A (B1)8a GND Pulse encoder, track B GND / opt. track B (B2)12c GND Pulse encoder +5 V GND / opt. +5 V (B3)20a internally connected Optional external current limitation (J5/6)

Attention! The soldering bridges B1-B3 must be connected only from the mid position of thesoldering point to one side. Defective soldering bridges can cause a short circuit. 2. GENERAL INFORMATION

The transistor servo amplifier MTRF 25...61/5-15 is a pulse width modulated unit which can easily bemounted into a 19"/3U rack. Its main application is driving servo motors in the 4-quadrant mode (4quadrant means that the amplifier can drive and brake the motor in either direction).During acceleration the 3 fold current can be output for a maximum of 5 seconds, whereby the motor canreach the 3 fold of its continuous torque rating as pulse torque.For operation you only need the power supply, the motor with or without DC-tacho or pulse encoder, andperhaps an external ballast circuit and a standard set value.

Advantages:

- On account of a special principle of modulation almost no phase noises from the amplifier or the motor- High efficiency through optimal drive of the final stage- A very small minimum load inductance and the low internal resistance of the amplifier result in a high dynamics- I2t current limitation- Protection for over voltage, over current and over temperature- Relay contact for brake relay at malfunction- 4 modes of operation (tacho/encoder/IxR/current control) can be chosen by means of a soldering bridge- For all the possibilities of adjustment there are multiple trimming potentiometers- Built-in ramp available- No auxiliary voltages needed- Internal and external current limitationThe amplifier is designed for a continuous current of 5 A and a pulse current of 15 A. In order to be ableto operate motors with different powers and nominal voltages, it is possible to change the intermediatecircuit voltage by varying the voltage supply in a wide range.


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3. TECHNICAL DATA

Rated voltage 25...61 VRated current 5 APulsed current 15 ATransformer voltage:Secondary 20...52 V AC / 7AFuse F1 8 AMTVoltage range of the set value inputs 0... ± 10 VInput impedance of set value inputs 44 kS 5 10 nFControl range of input attenuators P1: 17 - 100 %, P2: 0-100%Maximum tacho voltage ± 20 VControl range of the tacho attenuators 17...100% Maximum input drift ± 15 :V / /CBandwidth of cascade current controller 1 kHzClock frequency to earth 9 kHzMinimum load inductance 0.8 mHFrequency of current ripple 18 kHzForm factor of output current with minimumload inductance (0.8 mH) 1,01Efficiency 95 %Ready for work / relay contact 50 V / 50 mAContact "ready" disturbance = openAuxiliary voltage for external additional circuits ± 12 V / 20 mAMax. operating temperature 0/ ... 45°CStorage temperature -30 ... 70°CFitting position verticalCooling convectionControl range of ramp 70 - 600 msConnector structural shape 32 POL-DIN-41612-D-MALE

Suitable auxiliary equipment Ballast circuit MABASupport for pcb’s type DFront panel (dimensions 3HE, 8TE)Toroidal transformerChokes type: D 0,9- 18-6


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4. CONTROL PRINCIPLE

In a traditional DC motor there are two static magnetic fields which react together. The commutation ofthe armature winding is carried out by means of brushes and commutator segments.

The principle of speed control with cascade current control is applied here. The overriding speed controlcircuit consists of speed controller and the motor-(tacho/encoder)-combination. The speed set value ispreset externally by the user, e.g. by means of potentiometers or NC control system. The actual speedvalue is determined directly at the motor shaft, e.g. by means of a tacho generator, and is compared withthe speed set value at the first accumulation point. The determined difference is the input value of thespeed controller. From this control difference, the requested circuit set value which is passed on to thesubordinate control circuit is calculated.

The current control circuit consists of the current controller, the pulse-width modulator and the final stageof the amplifier. The actual current value is measured in the motor circuit and returned to theaccumulation point. Set value and actual value are compared and the difference is supplied to theamplifier which adjusts it to zero.

The advantage of this kind of regulation is that current limitations, which are necessary to protect themotor and the amplifier, can be easily realized by limiting the output voltage of the speed regulator(current set value).

Circuit diagramm MTRF 25...61/5-15, motor with tacho generator


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5. CONNECTIONS

32 POL-DIN-41612 structural shape D-Male

2a tacho +2c tacho -4a GND (optional: pulse encoder, track A)4c disable6a integral part off6c positive stop8a GND (optional: pulse encoder, track B)8c negative stop10a GND10c GND/ pulse encoder, 0 V12a set value input 212c GND (optional: pulse encoder, +5 V / 100 mA)14a ready for work14c ready for work16aa set-value input 1 non inverting16c set-value input 1 inverting18a -12 V max. 20 mA18c +12 V max. 20 mA20a internally connected (optional: external current limitation)20c Ia monitor22ac GND24ac motor +26ac motor -28ac intermediary circuit supply AC30ac intermediary circuit supply AC32ac intermediary circuit supply DC + UB

6. WIRING AND EARTHING

All control cables must be screened. The screen of the control cable must be connected to the control unit- and not to the amplifier! If the screen is earthed at both ends the advantages of the set value differentialinput are lost and, additionally, interference may arise.

The motor line should consist of a three-core separate, shielded cable with a section of minimum 1,5mm². The shield should be connected to the power-mass of the amplifier.

The cores of any chokes should also be connected to the earth of the amplifier in order to avoidmalfunction.

The EMC recommendation for “Line depending interferences” is observed in accordance to norm B, byusing the EMC interference protection filter type: FKE2-45-4/I. A capacitor of 1:F/250 V has to beincorporated parallel to the filter output in order to observe the norm for interference emissions. The filtermust be connected in front of the transformer. The filter and the capacitor can be supplied by us.


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7. EXPLANATION OF CONNECTIONS

7.1 INPUTS

7.1.1 Speed set value inputs (PIN 16a, 16c and 12a)

The speed set value can be supplied alternatively or combined by addition via the set value inputs 1and/or 2. Input 1 is a differential input, input 2 is a earth referenced input.

The differential input has several advantages compared with the earth referenced input: common modeinterference is suppressed and earth loops, which result in offset voltages, are interrupted. Adisadvantage of the differential input is that the set value has to be supplied by two phases. Preferably setvalue voltages up to ± 10 V should be supplied. The input impedance of the set value inputs is 44 kOhmà 10 nF. The set value input 1 may be attenuated by means of the input attenuator P1 in the range of 17... 100%. The input 2 can be attenuated with P2 in the range of 0-100%.

No needed inputs have to be grounded, in order to exclude disturbances that could be caused by spikes.This can be realized by means of the soldering bridge (J8) with internally set value 2.

7.1.2 Current limitation input (PIN 20a)

The current limitation input is usually needed for machines, e.g. in order to avoid the case ofmalfunctioning parts being moved by the drive with full torque and possibly damaging the machine, or e.g.in order to limit the winding tension at winding drives. The limitation could be done either through the input20a or through the internal potentiometer P7.The use of the external or internal current limitation can be selected by the soldering bridges J5 (closed-input 20a) or J6 (closed - potentiometer P7).If the input 20a is used, 1 V corresponds to a impulse current of approx. 1,5 A. A voltage > 10 V shouldbe avoided, as otherwise the impulse current could rise above the permitted value and the amplifier couldbe destroyed.


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7.1.3 Pulse encoder. Tracks A and B (PINS 4a and 8a)

The tracks A and B are connected to these inputs if the speed control is made by an encoder. Thesoldering bridges B1 and B2 must be changed (between 3 and 4 open, between 4 and V closed). Theresolution of the encoder should be of 500 pulses per revolution. It is possible to use other types, howeverthe amplifier should be adapted. If a 5 V encoder is used, it can be fed through the PIN 12c. For this, the jumper B3 must be changed(between 3 and 4 open, between 4 and V closed). The necessary current should not exceed 100 mA. 7.1.4 Disable input, release of the final stage (PIN 4c)

The disable input is active high, i.e. for an open input or positive input voltage > +10 V the motor isdisabled. For an input voltage of 0 to +1 V or GND the motor is enabled. Do not supply this input with anegative voltage or a positive voltage of over +20 V!!The final stage is switched off immediately when this input is active, but switched on with a retardation of200 ms. The switch off takes place immediately.

7.1.5 Integral disable (PIN 6a)

For positioning, the integral conduct of the controller is not required in all phases of a positioning process.Especially when reaching the set position, overshooting is possible. Therefore the integral part of thespeed controller can be switched off by disconnecting this input from ground.

This control input can also be used if in case of a set-value of 0 V the maximum holding torque is notdesired. In case of the integral part being switched off, the holding torque is only weak which prevents themotor from drifting off with a large torque (remaining deviation).

7.1.6 Limit switch "positive stop" (PIN 6c)

The “positive stop” input is high active. This pin must be connected to ground if the motor must run inpositive direction. If this connection is interrupted, e.g. by a limit switch (opener), positive set-values aresuppressed and the motor is braked with the switched-off integral part. "Negative" speed is still possible.


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7.1.7 Limit switch "negative stop" (PIN 8c)

This input has the same function as the positive stop input, but only for negative set-values.

If the “positive/negative stop” function is active, the integral part of the controller is switched off.

7.1.8 Tacho input (PIN 2a, 2c)

The tacho input is an earth referenced input and is designed for a tacho of 5 V/1000 rpm, this producesa range of tacho input voltage of -20 .... +20 V. For other configurations, we offer modified amplifiers.


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7.2 SUPPLY

7.2.1 Supply of the intermediary circuit (PIN 28ac, 30ac)

The supply of the intermediary circuit is done by means of a transformer, the secondary voltage of whichshould not exceed 60 V AC, as otherwise the ballast circuit is activated and could switch off the amplifier!

The secondary voltage must not exceed 70 V AC even at a short-time excess-voltage, as otherwise theelectrolytic capacitors could explode.

The secondary current of 5 A is sufficient if the maximum nominal current is not needed permanently.However, in case of higher demands we recommend a secondary current of 7 A.Should an adjustment of the motor voltage be necessary (Umot in V DC), a lower transformer voltage isrequested (UTransfo in V AC). The reference value is:

Utransfo = (Umot + 10) * 0.72

The minimum voltage should not exceed 20 V AC.

7.2.2 Battery supply (PIN 32ac, 22ac)

In the case of battery supply, use the DC-inputs provided for this; make sure that the polarity is correct!

The DC voltage may vary from 25...65 V. In the case of battery supply and correct connection thegenerated brake energy is fed back to the battery.

7.3 OUTPUTS

7.3.1 Output "ready" (PINS 14a, 14c)

The output "ready" is a potential free relay contact which is closed during operation. In this case, thegreen LED is illuminated. The contact can be loaded with a maximum of 50 mA or 50 V.


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7.3.2 Ia-monitor (PIN 20c)

At this output the actual current value can be measured with a voltmeter with an input resistance > 10Kohms. 1 Volt corresponds to a current of 2,35 Ampere.

7.3.2 Reference voltage source (PIN 18a, 18c)

A D.C. voltage of ± 12 V which may be loaded with up to 20 mA is made available here. This voltage canbe used to produce the speed set value.

7.3.4 Motor output (PIN 24ac, 26ac)

At the motor outputs only motors of an inductance of > 0.8 mH should be connected directly. Whenmotors of a lower inductance are used, a choke of => 0.4 mH has to be connected in each positive andnegative motor line.

The amplifier is short-circuit proof and short to earth proof if such a fault occurs behind chokes of at least0.4 mH!

Short circuits and shorts to earth directly at the amplifier's outputs can lead to the breakdown ofthe appliance; we cannot guarantee for any of these cases.

8. ADJUSTMENT POSSIBILITIES

Potentiometer P1: attenuation for set value input 1control range 17.....100%

Potentiometer P2: attenuation for set value input 2control range 0.....100%

Potentiometer P3: attenuation for EMF / tacho feedbackcontrol range 17.....100%

Potentiometer P4: offset adjustment of speed controller (motor standstill at set value = 0V)

Potentiometer P5: amplification of the alternating voltageof the speed controller

Potentiometer P6: effective current limitationPotentiometer P7: pulsed current limitation (in case of external limitation without function)Potentiometer P8: speed symmetry in case of encoder control, adjusted and sealed in our workshopPotentiometer P9: IxR compensationPotentiometer P10: ramp adjustment, retardation between 70ms - 600 ms

LED 1 (green): illuminated if amplifier is ready (alsoin the case of disable)

LED 2 (yellow): illuminated if the amplifier is in I2t-limitationLED 3 (red): illuminated in case of disturbance: over-voltageLED 4 (red): illuminated in case of disturbance: over-currentLED 5 (red): illuminated in case of disturbance: over-temperatureIf the LEDs 3-5 are illuminated, the amplifier must be switched off and on again.


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Soldering bridges:

J1: (TA) operation with taco generatorJ2: (EMK) EMF controlJ3: (IG) operation with pulse encoder J4: (RMP) ramp set value (closed = without ramp)J5: (EXT) external current limitationJ6: (INT) internal current limitationJ7: (+SW2) earth point for set value 2 (when not used)

J14: (on the SMD module) current controller

B1 standard: GND (soldering bridge between 3 and 4)optional: pulse encoder, track A (soldering bridge between 4 and V)

B2: standard: GND (soldering bridge between 3 and 4)optional: pulse encoder, track B (soldering bridge between 4 and V)

B3: standard: GND (soldering bridge between 3 and 4)optional: +5 V supply impulse encoder (soldering bridge between 4 and V)

9.SELECTION OF THE MODE OF OPERATION

Important! Chose only one mode of operation! (only close one bridge)

J14 : bridge current controller (soldering bridge on the SMD module)J1 (TA) : bridge for control taco (soldering bridge on the base pcb, soldering side)J2 (EMK) : bridge for EMF control (soldering bridge on the base pcb, soldering side)J3 (IG) : bridge for encoder control (soldering bridge on the base pcb, soldering side)

10. DIMENSIONS: MTRF 25...61/5-15


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11. INITIAL OPERATION

11.1 INPUT TEST CIRCUIT: MTRF 25...61/5-15, TACHO CONTROL

If a motor with tacho is used, the soldering bridge J1 must be closed (indicated with TA on the solderingside). We deliver the amplifiers with this mode of operation as a standard.

Important: correct polarity of motor and tacho

To be sure of the correct connection of the motor and its tachogenerator only an easy voltagemeasurement on the switched-off unit is necessary. Needed is a voltmeter with indication of the polarity.The motor shaft must be turned by hand into one direction. A voltage is originated in the motor cable(binder 24ac) and in the tacho cable (binder 2a), which are measured against mass. The polarity of thisvoltage is opposed (pos. and neg or neg. and pos.).If this is not the case, the respective connection tacho (2a with 2c) and motor (24ac with 26ac) cablesmust be changed.

In the case of a wrong connection, the motor will run at full speed and the set value will not have anyinfluence on the speed.If the motor runs with switched-on amplifier and the preset speed set value in a wrong direction, the tachoand motor cables must be changed.

The desired final speed can be adjusted with the tacho potentiometer P3, by setting the maximum speedset value of 10 Volt. If you don’t reach a stable control behaviour with this adjustment, you should turn the tacho potentiometerfurther to the right (higher speed) and adjust the final speed with the set value potentiometer P1 or P2.


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11.2 INPUT TEST CIRCUIT: MTRF 25...61/5-15, ENCODER CONTROL

If it is used a motor with one impulse encoder, the soldering bridge J3 (indicated with IG on the solderside) must be closed. In the same way the bridges B1-B3 between V and 4 must be closed.

In the case of wrong connection, the motor can work at full torque and the speed set value will not haveany influence on the speed. Then the motor or impulse encoder (tracks A and B) cables must bechanged. If the motor runs with switched-on amplifier ant the preset speed set value in a wrong direction, theimpulse encoder and the motor cables must be changed.

The desired final speed cab be adjusted with the tacho potentiometer P3, by setting the maximum speedset value of 10 Volt.If you don’t reach a stable control behaviour with this adjustment, you should turn the tacho potentiometerfurther tot the right (higher speed) and adjust the final speed with the set value potentiometer P1 or P2.

11.3 EMF CONTROL

If no tachogenerator or impulse encoder are available, the jumper may be positioned to “EMK”. In this case the soldering bridge J2 (indicated with EMK on the solder side) must be closed.The adjustment of the speed described in 11.2 (tacho control) is applicable here.The I*R-compensation potentiometer P9 can minimize a speed deviation between no-load operation andload. The I*R compensation causes a rise in the output voltage, which compensates the voltage drop dueto the internal motor resistance. This is in proportion to the current consumption und thus opposes thespeed drop at rising loads.

11.4 CURRENT CONTROL

The soldering bridge to be closed is on the SMD module and is indicated as J14.The soldering bridges for tacho/ EMK/ Encoder operation must be open.In case of cascade position control, only a current control is often required. In this case, the speedcontroller of the MTRF 25...61/5-15 is bridged (gain=1). The voltage supplied to the set value correspondsto the motor current and thus to the torque. The set value potentiometers P1 or P2 should be on the rightposition. In this case 10 V at the set value input corresponds to an impulse current of 15 Ampere.In this mode of operation, the speed can not be regulated and even with small set values and without loadthe motor runs with a high speed. By setting a set value von 0 Volt, the motor should not develop anominal torque value.


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11.5 PRE-ADJUSTMENT

At delivery, the regulator is pre-adjusted by the manufacturer.In case of an eventual maladjustement, we recommend adjusting the amplifier as follows:

- set input attenuators P1 and P2 to the mid position- set tacho/ e.m.f. pot P3 to the mid position- set offset pot P4 to the mid position- set amplifier pot to the left position- for e.m.f. regulation set P9 to the left position- ramp potentiometer P 10 to the left position

11.6 ADJUSTMENT OF EFFECTIVE CURRENT AND PULSE CURRENT INTERNALLY(J5- OPEN, J6- CLOSED)

In order to adjust the pulse current, either supply a set-value of 0 V * and turn the motor manually fromthe zero point or block the motor and adjust a constant set-value. The potentiometer P7 adjusts thedesired pulse current, if the I2t current limitation responds (the yellow LED lights up), open the disableinput (4c) for approximately 20 seconds so that the amplifier can recover; after having been closed again,the adjustment can be continued. After the end of the pulse current phase the current is reducedautomatically to the effective current, adjustable at P6. In order to adjust, turn P6 gradually and without hesitating. After a short adjustment time during which thecurrent is 0 or I-imp, the new continuous current flows.We recommend you to limit the effective current in such a way that it corresponds to the nominal currentof the driven motor in order to protect the motor in case of a mechanically blocked shaft or in case ofover-load. An adjustment of the potentiometer P7 or P6 to the left reduces the respective currents.The duration of the pulse current phase depends on the adjusted ratio: Iimp/Ieff. If the controller isadjusted according to his nominal data, the pulse current phase lasts approximately 5 seconds. If the ratiois increased, for example of 3:1, the time decrease, for a smaller ratio, the time is longer.

Annotation:In order to measure the adjusted currents, the motor can be replaced by an ammeter with a suitablemeasuring range. However, the necessary minimum load inductance (0,8 mH) must be secured, i.e. itmust be realized by the chokes.

11.7 OFFSET ADJUSTMENT

Now, after all the previous adjustments have been effected, the offset adjustments can be made. For thispurpose, a set value of 0* is supplied again and any drifting of the motor shaft is eliminated by adjustingP4.

*The set value of O Volt is the easiest to realize, by grounding all the set value inputs to 10ac (see input testcircuit).

11.8 RAMP ADJUSTMENT

The set value ramp is only active when the soldering bridge J4 is open.In case of a set value alteration, the motor accelerates or brakes to a linear time function. This isadjustable in potentiometer P10.The adjustable delay times are of 70 ms (P10 left position) - 600 ms (P10right position), in case of a set value bounce of 10 Volt. The times can still be prolonged on the SMD module by means of a capacity increase of the capacitorC40 (standard value 100nF).There is a linearity between the capacity increase and the reachable ramp. For example, to double thecapacity, results in a adjustable times of 140 ms- 1200 ms.

The mentioned times refer to a disk-armature motor type MAM/H/190, with unloaded shaft, and are validwhen the respective input potentiometer is adjusted to the right position.


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11.9 BALLAST CIRCUIT (NOT INCLUDED IN THE AMPLIFIER, AVAILABLE AS OPTION)

Depending on the application, it may be necessary to use a ballast circuit type MABA. This circuit controlsthe intermediate circuit voltage and converts in heat the motor’s braking energy, which is not absorbedby the electrolytic capacitor.It is connected to the 32 channel plug, between pin 32ac (VCC) and pin 22ac (GND).

11.10 CONNECTION TO AN EXTERNAL ENCODER

The set value wiring has to be shielded. The screen must be connected to ground at the set valueencoder. In addition a mass connection of 1 mm² has to be made between set value encoder andamplifier.

12. OPTIMIZATION OF THE CONTROL BEHAVIOUR

12.1 ALTERNATING VOLTAGE AMPLIFICATION

In most of the cases the optimization is limited to the adjustment of the alternating voltage gain at pot P5.The alternating voltage gain determines the torque and therefore the speed with which the amplifierreadjusts (dynamic stiffness). For this purpose, couple the motor to the load and supply a set value of 0 V. This can be done by bridgingthe set value input with pin 10ac (GND).

Turn pot P5 to the right until oscillation starts and then turn in immediately to the left in order fo find thepoint at which oscillation stops.

12.2 DIRECT VOLTAGE AMPLIFICATION

Especially in the case of a cascade control circuit an exactly specified static stiffness is often required.This stiffness corresponds to the torque, with which a position is hold.

The stiffness can be changed by the resistance R125 on the SMD module. If this resistance is increased,the stiffness decreases. This static stiffness should not be confused with the dynamic stiffness which canbe adjusted by potentiometer P5.

12.3 INTEGRAL PART OF THE SPEED CONTROLLER

The capacitor C38 on the SMD module is responsible for the integral part of the speed controller. The demands on the dynamics of amplifiers working as speed controllers differ considerably from thedemands on amplifiers working with overriding position control circuits.In the first case, stiffness has to be produced by the speed controller which therefore must have anintegral gain as high as possible (the capacity of C38 must be low). In most applications a short-timeovershooting is allowed.

In operation with an overriding position control circuit, the position control circuit produces the stiffness.It is of great importance that the amplifier has a band width as large as possible whereas the integral gaincan be considerably lower than in the first case (the capacity of C38 must be high). The overshooting ofthe amplifier without position control gets a little smaller, however, the braking time till motor standstill isa little longer.


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13. MTRF AS A FOLLOW-UP AMPLIFIER MTNRF 25...61/5-15

If the motor runs uncontrolled after switching on, or oscillates at one place, the tacho cables or thebeginning and end of the actual value potentiometer at the motor must be changed. In order to check thecorrectness of the wiring of the actual value potentiometer, the soldering bridge “Mode of operation(Betriebsart)” must be positioned to “EMK control”, then the tacho feedback is interrupted.A defective tacho cable or a wrong potentiometer adjustment can cause an oscillation. If it is caused bya wrong potentiometer adjustment, the tacho/EMK potentiometer P3 must be adjusted to the left (durationof the position longer). The initial adjusted position duration can be reached again by changing the inputattenuator P1. To do it, the attenuator should be adjusted to the right.

Test circuit: MTNRF 25...61/5-15


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14. PLAN OF COMPONENTS: MTRF...61/5-15

Basic pcb


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SMD-module

15. TROUBLE SHOOTING

Faults:Possible causes:

No reaction, green LED is not illuminated Check the DC power voltages. If one of the voltages aremissing, check the wiring.

Green LED is illuminated, no other reaction No contact at limit switch (enable/disable) input. Breakin motor circuit. Check motor output with a voltmeter.Check the fuse on the final stage PCB.

There is a reaction, but no torque at themotor shaft

Is the current set value = 0?Is P6/P7 on the left position?

Noise interference in motor current Common-mode interference at the differential input is tohigh. Install a separate earth cable of GND, for examplepin 22ac to the central 0 V-point of the control unit.

Motor runs uncontrolled at high speed. Absence of tacho voltage or incorrect tacho connectionpolarity. Jumper JP1 on I-control.

Maximum motor speed is too low Set value is too low, tacho voltage is too high, operationvoltage is too low, load too high. Input potentiometer P3on right position; check operation voltage and comparewith motor e.m.f. at the desired speed; increase pulseor maximum effective current for a short time in order toprove the overload: the speed should increase.


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Too much drift Unfavourable input circuitry; inputs are reduced;interference voltage at the input cables. Potentiometerof input on maximum. Check connections with regard toearth currents.

Over current alarm (with internal disable)at high speeds

Commutation limit of motor exceeded; choose smalleroperation voltage and/or reduce peak current.

Audible howl at constant frequency andmotor shaft instability

Torsional resonance due to weak attachment oftachogenerator. Improve the tacho/motor coupling oruse a tacho with a lower moment of inertia.

Imprecise regulation with a large overshooteven with low gain

Inductive phase angling rotation due to a large motorinductivity and small mechanical time constant. Use amotor with a smaller inductivity; increase the workingvoltage.

Rumbling, rhythmic running noise withearly activation of I2t limit

Tacho voltage ripple too large, use a better tacho orreduce the amplifier's gain (P5).

Continuous available power too low,current limit activates too early

Load too large, possibly friction losses or constraints inthe machine. Check the actual motor current. Avoidunnecessary high accelerations and decelerations.

Motor gets hot, even without load Temperature rise due to hysteresis losses. Reduceoperating voltage or attach reactors (chokes)in serieswith the motor.

Electrical interference too high Wiring not correct. Mount reactors (chokes) directlyadjacent to the amplifier and ground the cores toterminal 10ac. If controlling the amplifier from anexternal control system ground the control input cablescreens AT THE CONTROLLER and not at theamplifier. Insert 330 ohm resistors in the control linesfrom the external controller.

Red LED over-voltage illuminated Power supply too high. During start-stop operation,braking energy too high, use external ballast circuitMABA.

Red LED over-current illuminated Earth- or short-circuit at motor output.

Red LED over-temperature illuminated Ambient temperature of the amplifier too high; take careof the heat dissipation.

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