DE2244763A1 - CONTROL CIRCUIT FOR A DIRECT CURRENT SERIES MOTOR SUPPLIED FROM AN AC SOURCE - Google Patents

Description

Patent Attorneys D! P! .- Itst ·, W. Scbeiraioan D.vtog. 1 ROger

73 Esslingen (Neckar), Fdbrikstrasse 9, PO Box 348 September 12, 1972

PA 27 telephone

Stuttgart (0711) 356539

Telegrams patent protection Essllngennedcar

SQUARE D COiIPANY, Executive Plaza, Park Ridge, Illinois 60066

United States

Control circuit for a direct current series connection motor fed from an alternating current source

The invention relates to a control circuit for a direct current series motor fed from an alternating current source in which the speed of the motor by an assigned main switch optionally in a first switching range in the one direction of rotation and can be regulated in a second switching range in the other direction of rotation and by signal generating means when the main switch is in the first switching range, a voltage of a first polarity and when in the second Switching range standing main switch, a voltage of a second polarity can be generated. The AC power source can be single-phase or three-phase.

The invention is based on the object of creating a control circuit for a direct current series motor fed from an alternating current source, which, with a straightforward structure, enables simple control of the speed of the motor in ^! permitted in both directions of rotation, the circuit being used in particular in addition to other areas of application

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to control hoists, such as cranes is possible.

To solve this problem, the control circuit is according to of the invention characterized in that it has two input side connected to the AC power source has controlled AC-DC converter, the control inputs of which via a reference control circuit with the Signal generating means are connected and of which when a voltage of the first polarity occurs on the Signal generating means only the first AC-DC corrector emits an output direct current and when a voltage of the second polarity occurs the signal generating means, both AC-DC converters output a DC output and that the Armature and the excitation winding in series with the main switch in the first switching range to the Output terminals of the first AC-DC converter are connected and in the second switching range standing main switch the armature with the output terminals of the first AC / DC converter and the excitation winding are connected to the output terminals of the second AC-DC converter and through a between the armature and the excitation winding in series-connected insulation resistance there is a relationship between the excitation of the excitation winding and the voltage applied to the armature when in the second switching position standing main switch is established.

In a preferred first embodiment, which is also a Is of independent importance, the arrangement can be made in such a way that in series with the excitation winding the output terminals of the first AC-DC

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converter connected armature parallel to the armature an auxiliary excitation resistor is located, which is controlled by Current measuring means at a predetermined value of the Output DC current of the AC-DC converter can be switched off from the armature.

In another embodiment, which is also a is of independent importance, the aforementioned control circuit according to the invention is characterized in that that with the output terminals of the first AC-DC converter connected armature and to the output terminals of the second AC-DC converter connected excitation winding parallel to the armature, a dynamic braking resistor is connected and that the disconnection of the dynamic braking resistor by means of current measuring means at a predetermined size of the DC output of the first and second AC-DC converters can be triggered.

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In the drawing, an embodiment of the subject matter of the invention is shown. Show it:

Fig. 1 A schematic circuit diagram, partly in a block diagram a lift control circuit according to the invention,

Figure 2 is a schematic circuit diagram of a reference control circuit for the lift control circuit according to Fig.

3 shows a schematic circuit diagram of a load sensing unit for the stroke control circuit according to FIGS. 1 and

Fig. 4-9

Diagrams to illustrate the relationship between the output voltage of a signal converter the stroke control circuit according to FIG. 1 and individual amplifier voltages of the reference control circuit according to Fig. 2.

A preferred embodiment of a thyristor swing control circuit is shown in Fig. 1, in which a DC motor with an armature 11 A and an in Series lying excitation winding 11 A from a three-phase alternating current source L1 - L2 - L3 fed and used for the optional lifting and lowering of a load 14. A overload limit switch 15, which acts as a circuit breaker is designed and can preferably be actuated by the load 14 is provided in a manner known per se. The limit switch 15 has two sets of normally open contacts 15a, 15b and two sets of normally closed Contacts 15c, 15d. The armature 11 A is an electromagnetically releasable one that is incident under spring force Friction brake 16 assigned to an excitation winding 16 w.

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Between a connection point 19 and a connection point 20 is a conductor 17, the one the connection point 19, the normally open contacts 21 a one first electromagnetic lift switch 21, the limit switch contacts 15c, the armature 11 A, the limit switch contacts 15d, an insulation resistor 22, the motor excitation winding 11 F, the excitation winding 16 w of the Brake 16, the normally open contacts 24a of a main switch 24, a winding 25 w of an overload relay 25, one as the first current indicator or current measuring resistor 26 serving resistor and the connection point 20 containing series circuit forms. The whole circuit is preferably grounded at connection point 20.

A conductor 27 forms a series circuit between the connection point 19, via the normally open Contacts 28a of an electromagnetic lowering switch 28, the limit switch contacts 15b and a limit switch resistor 29 up to the side of the field winding 11 F facing the field winding 26 w of the brake 16. The conductor 27 is connected between the contacts 28a and 15b via a winding 30 w of a limit switch relay 30 the conductor 17 at one between the contacts 21a and 15c lying point and by the series connection of a dynamic braking resistor 31 and normally closed Contacts 32a of an electromagnetic dynamic brake switch 32 on the limit switch contacts 15c adjacent side of the armature 11 A connected, while a further connection between the conductor 27 and the conductor 17 through a conductor 34 to the limit switch contacts 15d adjacent side of the armature 11 A is made.

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There is a connection on one side of the armature 11A through a conductor 35, two normally closed contacts 36a of an auxiliary electromagnetic excitation switch 36, an auxiliary field resistor 37 and two normally open contacts 39a of a second electromagnetic Hub switch 39 to the side of the excitation winding 11 A adjacent to the insulation resistor 22. Two normally closed contacts 41a of an electromagnetic dynamic lowering switch 41 are through one Conductor 40 connected between one side of the armature 11 A and the other side of the excitation winding 11 F. A Conductor 42 connects the normally open limit switch contacts 15a to one facing the armature 11A Side of conductor 40 as well as on one between the limit switch contact 15d and the insulation resistance 22 lying point with the conductor 17. The conductor 42 is also between the auxiliary excitation nerve / resistance 37 and the lifting contacts 39a connected to the conductor 35.

A first controlled rectifier, preferably in the form of an AC / DC converter 44, has its DC output connected to the connection point 19 by means of a conductor 45 via a winding 46 w of an overload relay 46; it is also connected to the connection point 20 by means of a conductor 47. The AC / DC converter 44 can be either single-phase or three-phase, depending on the particular requirements of the motor; it can be either a half-wave or a full-wave converter; the corresponding circuits are known per se. A second controlled rectifier, preferably also in the form of an AC / DC converter 49 _; is connected with one side of its DC output by means of a conductor 50 to one side of the excitation winding 11 F next to the insulation resistor

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stood 22 connected »The other side of the equal exit of the AC-DC converter 49 is by means of a conductor 51 via a second current measuring resistor connect with junction 20 * The We'chselström direct current converter 49 can also be single-phase or three-phase; however, the converter can be used if a limit switch does not have a free-running diode be equipped »If necessary, the AC-DC converter 49 have three thyristors, each of which is connected to a branch of the secondary winding 53 b is. The neutral conductor of the secondary winding 53 b would then form an output terminal of the converter 49, which is used to connect the conductor 51 »

The alternating current DC converter 44, 49 are fed by secondary windings 53 a or * S3 b of a transformer. The transformer 53 has a primary winding 53 p, which is connected either in a delta or in a star and is connected to an alternating current source L1 «- L2 - L3. The secondary winding 53 a is connected to the AC / DC converter AA via conductors, while the secondary winding 53 b is connected to the AC / DC converter 49 via a conductor 55 the motor control circuit according to the invention could also be used, if necessary, with a single-phase power supply and that the secondary windings 53 a, 53 b could be excited by separate primary windings.

Single-phase alternating current from the alternating current source L1-L2 is fed via zv / ei conductors 56 to a primary winding 57 ρ of a transformer 57 which has a secondary winding 57 s »The secondary winding 57 a of the transformer S7

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supplies the control circuit with electrical energy, as will now be described in detail.

The motor is controlled by a reversible main switch 58 having a plurality of switching positions, such as for example, it is described in U.S. Patent 3,221,246 is. Operating voltage is fed from the secondary winding 57 to a rectifier 60 via two conductors 59, during two conductors 61 operating voltage from the secondary winding 57 s via normally open auxiliary contacts 24 b of the main switch 24 in the series-connected primary windings 62 ρ, 64 ρ of two differential transformers 62, 64 feed, as explained in the mentioned patent.

The rectifier 60 converts the alternating current supplied by the secondary winding 57 s of the transformer 57 into direct current around; it can be designed in the form of a conventional diode bridge rectifier, the output of which is through a positive conductor 65 and a negative conductor 66 is formed. The main switch 58 has normally closed Contacts 67 and six normally open contacts 69-74. The closed or open state of the Contacts 67 and 69-74 in the raised or lowered position will be substantially more rectangular by the presence or absence Blocks indicated, which are aligned with the respective contacts. For example, contacts are 69 closed in the lifting range of the main switch 58, while they are open in the lowering range. Contacts 67 and 69 - 74 control the excitation of the working windings of various switches and relays, with the excitation current passing through the conductors 65, 66 is fed.

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A working winding 75 w of an undervoltage relay 75 is excited by the contact 67 when the main switch is in an OFF position; it is normally through when the main switch is in other positions open contacts 75 a of the relay 75, which are in the conductor 65, held in the energized state. Normally closed contacts 25 a of the overload relay 25 and normally closed contacts 46 a of the overload relay 46 are located in series with the working winding 75 w of the undervoltage relay 75, the mode of operation, circuit and functions of the overload relay 25, 46 and the undervoltage relay 75 are known per se.

A winding 41 of the dynamic lowering switch 41 becomes the normally closed auxiliary contacts via the contact 69 ixnd 28 b of the lower switch 28 in the stroke range of the main switch 58 is excited. Is parallel to the winding 41 w one via the contacts 69, 28 b excitable winding 21 w of the first lift switch 21, which by normally open auxiliary contacts 41 b of the dynamic lowering switch 41 is connected. There is also a parallel Winding 39 w of the second lift switch 39, the connection of which via normally open auxiliary contacts 32 b of the dynamic Brake switch 32 happens and finally a winding 36 w of the auxiliary exciter switch 36 is parallel, which over normally open contacts 76 a of a first load sensing relay 76 (Fig. 3) is connected.

TO -

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A winding 28 w of a lowering switch 28 is normally closed via the contact 70 and auxiliary contacts 39 b of the second lift switch 39 excited when the main switch 58 is working in its lift range.

A winding 32 w of the dynamic brake switch 32 is excited via the contact 71 in the stroke range of the main switch 58 as well as via contact 72 and normally open contacts 30 a of the limit switch relay 30 in the overdrive - lowering range of the main switch 58 and

the
via / contact 73 two normally open contacts 77a of a second load sensing relay 77 (FIG. 3) and the contacts 30a in the intermediate gear and overdrive lowering range of the main switch 58.

The "· excitation of a winding 24 w of the main switch 24 occurs over the contact 74 in the entire lifting and lowering range of the main switch 58.

The differential transformers 62, 64 have secondary windings 62 s, 64 s, which are connected to a signal converter 79 which converts an AC input into a DC output, preferably with a negative one Output voltage during lifting operation and a positive output voltage during lowering operation; reshaped as mentioned in the US patent is explained. However, ice should be pointed out that any direct current source with controllable voltage can be used as signaling means, one output voltage of one polarity during lifting operation and one output voltage of the other during lowering operation Gives off polarity. This DC output is fed through a conductor 80 to a reference control circuit 81 which

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will be described in detail with reference to FIG will be. A load sensing unit 82 is electrically connected to the first measuring resistor 26 via a Conductor 83 and connected to reference control circuit 81 by conductor 84; their mode of action is in the each of them will be explained with reference to FIG. 3.

The reference control circuit 81 is connected to the second measuring resistor 52 via a conductor 85; She gives a control output variable via two conductors 86, 87 to a first ignition circuit 88, which in turn sends the first AC-DC converter 44 controls. The reference control circuit 81 also outputs one through conductors 89, 90 Control output to a second ignition circuit 91 from which

controls the second AC-DC converter 49.

The reference control circuit 81 is best referred to described on Fig. 2; it receives a DC input voltage via the conductor 80 from the signal converter 79, as can be seen from FIG. Part of the circuit according to FIG. 1 is shown in FIG. 2 for better clarity because of repeated. The output of the reference control circuit 81 is via conductors 86, 87 of the first ignition circuit 88 and The second ignition circuit 91 is supplied via conductors 89, 9O.

A conductor 92 connects the conductor 80 via a diode 94 to an input resistor 95 of an inverter amplifier 96, which has a feedback resistor 97. The diode is via a conductor 99 with a lift condition circuit 100 connected. The lift condition circuit 100 generates a Fixed negative output voltage as a function of a variable negative input voltage that is applied across the conductor 99 is supplied in a manner known per se. This out

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output signal is an input resistor 101 of the amplifier 96 and via the conductor 87 of the first ignition circuit 88 supplied. The conductor 84 also transmits this output voltage to the load sensing unit 82 (see also FIG. 1). An adjustment potentiometer 102 for the minimum lifting speed lies between the input resistance 95 and the input resistance 101; its tap arm 102 w is grounded. The output of amplifier 96 is fed to the first ignition circuit 88 via the conductor 86.

A conductor 104 connects the conductor 80 via a diode 105 to a lowering condition circuit 106, an input resistor 107 of a non-inverting amplifier 108, an input resistor 109 of an inverting amplifier 110 and a conductor 111 which is connected to an input resistor 112 of the inverting input of an amplifier 113.

The lowering condition circuit 106 generates a fixed negative output voltage as a function of a positive variable input voltage. This output voltage is fed to the first ignition circuit 88 via the conductor 87 and to the second ignition circuit 91 via the conductor 89. The output of the lowering condition circuit 106 is also fed to an input resistor 114 of the inverter input of the amplifier 113.

The amplifier 108 has a feedback resistor 115; its input resistor 160 is connected to a negative voltage source 117. The output variable of the amplifier 108 is fed to an input resistor 119 of an inverter amplifier 120 with a feedback resistor 121. A second input resistor 122 of the amplifier 120 is connected to a positive voltage source 124.

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closed, while a third input resistor 125 is connected to the collector of a transistor 129 by means of a conductor 126. A conductor 130 transmits the output of the amplifier 120 via a diode 131 and a conductor 132 to an input resistor 133 of the amplifier 96.

The amplifier 110 has a feedback resistor 134. The input resistor 109 of the amplifier 110 is connected via a conductor 135 through a diode 136 to the emitter of a transistor 137 which is connected to earth via a resistor 139. The collector of transistor 137 is connected to a positive voltage source 140, while the base of transistor 137 is connected to the tap arm of a potentiometer 141 which is connected to a positive voltage source 142 on one side. The other side of the potentiometer 141 is connected to the connection point 145 between a diode 146 and a diode 147 by means of a conductor 144. The diode is connected to a positive voltage source 148 and via a conductor 149 via normally closed contacts 30b of the limit switch relay 30 to a negative voltage source 150. The diode 147 is connected to the negative voltage source 150 by means of a conductor 151 via normally open auxiliary contacts 32c of the dynamic breaker switch 32 and normally open auxiliary contacts 28c of the lowering switch 28. In addition, the diode 147 is connected to a positive voltage source 152 and connected via a conductor to the base of the transistor 129. The emitter of the transistor 129 is connected to ground, while the collector of the transistor 129 is connected to a negative voltage source 157 via a resistor 156.

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The output voltage of the amplifier 110 is via a conductor 159, a diode 160 and the conductor 132 to the input resistance 133 supplied. As already explained, the output of the amplifiers 120, 110 are via diode 131, 160 at the input resistor 133 of the amplifier 96.

The output voltage of the second measuring resistor 52 is via the conductor 85 to an input resistor 161 Inverter amplifier 162 with a feedback resistor 163 supplied. The output of amplifier 163 becomes an input resistor 164 of a feedback resistor 165 having amplifier 113 supplied. The conductor 111 is at the input resistor 112 via a potentiometer 166 connected to ground, the tap arm to the non-inverting input of an amplifier 113 and to the Collector of a transistor Ί67 is connected. The emitter of transistor 167 is connected to ground, while the base of transistor 167 is connected to connection point 145.

The load-sensing unit 82 to be described in the simplest reference to the Fig., Also includes forming a part of the circuit shown in FIG. 1. The input variable is fed to the load sensing unit 82 from the first measuring resistor 26 via the conductor 83 (see also FIG. 1) and from the reference control circuit 81 via the conductor 84 (see also FIG. 2).

The conductor 83 carries the input voltage coming from the first measuring resistor 26 to an input resistor 168 Inverter amplifier 169 with a feedback resistor 170 too. The output voltage of amplifier 169 becomes a Input resistance 171 of an inverter amplifier 172 having a feedback resistor 174 is supplied. Between one positive voltage source 177 and a ground conductor 179 is located

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Via a conductor 176, a potentiometer 175, whose tap arm 175 w with an input resistance 180 des Amplifier 172 is connected.

The input terminal of the amplifier 172 is connected to a resistor combination via a conductor 181, which has a resistor 182 which is parallel to the series-connected resistors 184, 185. A connection point 186 between the resistors 184, 185 is connected to the collector of a transistor 187, whose Emitter is connected to a ground conductor 189.

The connection point of the resistors 182, 185 is via a Conductor 190 connected to a tap arm 191 w of a potentiometer 191, which is between the ground conductor 189 and a Diode 192 is located. The diode 192 is connected via a conductor 184 connected to the base of a transistor 185. The conductor forming an input from the reference control circuit 81 84 is connected to conductor 194.

The output voltage of the amplifier 172 is an input resistor 197 of an inverter amplifier via a conductor 196 199 fed to a feedback resistor 200.

The output of the amplifier 199 is transmitted via a conductor 201 to a voltage divider, which is in series has lying resistors 202,204,205 and is connected at its end to the ground conductor 179. A ladder 206 connects the collector of transistor 195 to the ground conductor 179, while the emitter of the transistor 195 at a point lying between the resistors 204, 205 with the Voltage divider is connected.

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The voltage divider is at a point lying between the resistors 202, 204 by means of a conductor 207 via a diode 209 with an input resistor 210 of an integration amplifier 211 and by means of a Conductor 212 through a diode 214 with an input resistance 215 of the amplifier 211 connected. The amplifier 2.11 has a feedback capacitor 216. Die The output of the amplifier 211 is fed through a conductor 217 to the base of a transistor 209, the Emitter is connected to the ground conductor 179 and its collector via a conductor 220 to a connection point 221 is connected.

The connection point 221 is by means of a conductor 222 via a counter capacitor 224 with an input resistance 225 of the Amplifier 211 and by means of a conductor 226 via a Resistor 227 with a positive voltage source 229 and by means of a conductor 230 with the base of a transistor tied together. The emitter of transistor 231 is connected to a positive voltage source 233 via a conductor 232, • while the collector of transistor 231 by means of a conductor. 234 via a diode 235 and a resistor 236 with a negative voltage source 237 is connected. Between the diode 235 and the resistor 236 goes from the conductor a conductor 238 which is connected to the base of the transistor 187 via a diode 239. A conductor 240 connects the collector of transistor 231 to the base of a transistor 241 and via a conductor 242 to the base of a Transistor 243. The collector of transistor 241 is connected to a winding 76 w of the first load sensing relay 76 positive voltage source 244, while the emitter of the Transistor 242 is connected to a negative voltage source 245. The emitter of transistor 243 is with a

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negative voltage source 246 connected, while the collector of transistor 241 via a winding 77 w of the second load sensing relay 77 is connected to a positive voltage source 247. A conductor 249 connects the collector of transistor 241 via normally open auxiliary contacts 32 d of the dynamic brake switch 32 with a negative voltage source 250.

With reference to Figs. 1-3, the thyristor controlled stroke control circuit according to the invention is intended in described below on the assumption that the armature 11 A and the field winding 11 P having Depending on the corresponding actuation of the main switch 58, the motor can either lift a load 14 or should lower.

When the main switch 58 is in its OFF position, the main switch contacts 67 are closed, while the main switch contacts 69 - 74 are open. It will therefore from the amplifier 60 to the working winding 75 w of the undervoltage relay 75 voltage applied, which its contacts 75 a closes and builds up a holding circuit via a conductor 251 in a manner known per se.

If an operating handle of the main switch 58 is now in a direction corresponding to the lifting operation of the motor adjusted, ^ the normally closed main switch contacts 67 open, while the normally open main switch contacts 69, 71, 74 are closed v / ground. As a result of the excitation of the working winding 2 4 v; of the main switch 24 via the main switch contacts 74 are the Contacts 24 a, 24 b closed. The winding 32 w of the dynamic brake switch 32 is via the main switch contacts 71 excited; the normally closed contacts

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224A763

are therefore opened, while the normally open contacts 32 b, 32 c (Fig. 2) and 32 d (Fig. 3) closed v / earth.

The excitation of the winding 41 w of the dynamic lowering switch 41 via the main switch contacts 69 has the consequence that the contacts 41 a open and the contacts 41 b closed v / earth. Closing the contacts 41 b allows the winding 21 w of the first lift switch to be excited 21, whereby its contacts 21 a are closed. Since the contacts 32 b were closed, is the winding 39 w of the second stroke switch 39 is also excited so that the contacts 39 a close. Contacts 39 b are opened to prevent the lowering switch 28 from being actuated. Before energizing the winding 7 G w des first load sensing relay 76 (Fig. 3) is the auxiliary exciter switch 36 not actuated.

In this way, a lifting circuit for exciting the armature 11 A and the excitation winding 11 F of a series motor constructed, whose circuit includes the first AC-DC converter 44, the conductor 45, the overload relay winding 46 w, the connection point 19 ", the conductor 17, the first hub contacts 21 a, the limit switch contacts 15c, armature 11 A, limit switch contacts 15 d, the second hub contacts 39 a, the field winding 11 F, the brake winding 16 w, the main contacts 24 a, the overload relay winding 25 w, the first measuring resistor 26, the connection point 20 and the conductor 47 contains. The auxiliary excitation resistance 37 is parallel to the armature 11 A via the still closed contacts 36a.

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During the lifting process, the motor is only powered by the first AC / DC converter 44 fed; the second AC-DC converter 49 does not operate. There, as from the circuit diagram the main switch 58 shows, the lifting process is going on without a step, the speed of the motor by changing the output voltage of the first AC-DC converter 44 controlled.

When adjusting the operating handle of the main door switch 58 in the stroke direction, a negative output voltage is generated in the signal converter 79 and via the Conductor 80 is fed to the reference control circuit 81.

This negative output voltage of the signal converter 79 is, as understood from Fig. 2, transmitted by the diode 94 and blocked by the diode 105, so that a negative voltage is only applied to the input resistor 95 of an amplifier 96 and the stroke condition circuit 100. The stroke condition circuit 100 transmits fixed negative output voltages as a function of the negative input voltage to the input resistance 101 of the amplifier 96, via the conductor 67 to the first ignition circuit 88 and via the conductor 84 (see also FIG. 1) to the load sensing unit 82. The through the lift condition circuit 100 to the The voltage applied to the first ignition circuit 88 acts as an enable input variable "which enables the first ignition circuit 88, so that it can respond to an operating input voltage supplied through conductor 86. As the lowering condition circuit 106 is not made effective during the lifting process, the second ignition circuit 91 remains because of the lack one release input is locked so that the second

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AC-DC converter 49 remains ineffective.

The amplifier 96 produces a positive output voltage, which is proportional to the sum of the input voltages fed to the input resistors 95, 101: This output voltage is fed via the conductor 86 of the first ignition circuit 88, which in a known manner a corresponding Output voltage of the first AC-DC converter 44 causes.

The amplifier 96 through the stroke condition circuit Constant negative input bias applied through input resistor 101 sets the minimum output voltage of the amplifier 96 and thus also that of the first AC-DC converter 44 to the motor applied minimum output voltage. The input voltage at the resistor 101 therefore determines the smallest Engine operating speed and thus also the lightest load 14 which the engine is floating when the brake is released, i. E. can be held motionless. If the minimum operating speed of the engine changes or a lighter one Load 14 is to be kept floating, the tap arm 102 w of the setting potentiometer 102 for minimum load adjusted in such a way that the earth connection either continues to the input resistor 101 or further from this is moved away, whereby the bias voltage applied to the input resistor 101 experiences a change. If the tap arm 102 w closer to the input resistance 101 brought up, the input voltage is lowered and thus also the minimum speed setting in a corresponding manner of the motor. By moving the tap arm 102 w away from the input resistor 101, the latter becomes Input voltage increased.

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Although it is expedient to have the possibility of changing the minimum speed setting of the motor, this setting should not influence the maximum speed of the motor which can be achieved at the maximum speed setting of the main switch 58. The input resistor 95 is therefore connected to the other side of the potentiometer 102. If the pickup arm 102 w is moved in the sense of increasing the voltage at the input resistor 101, a corresponding decrease in the voltage supplied via the input resistor 95 is achieved at the same time. Conversely, if the tap arm 102 w is adjusted in the sense that the voltage applied to the input resistor 101 decreases, there is a corresponding increase in voltage at the input resistor 95 a change in the input voltage at resistor 101 is compensated for. With the minimum speed setting of the main switch 58, the voltage supply via the resistor 95 is low, so that only a minimal compensation is present. However, if the output voltage of the signal converter 79 requires the maximum lifting speed, the input voltage supplied via the resistor 95 is sufficiently large to fully compensate for the change in the input voltage brought about by the resistor 101, so that regardless of the respective setting of the minimum lifting speed the maximum lifting speed always remains essentially the same.

The auxiliary excitation resistor 37 is, as is known per se, a relatively high resistance lying parallel to the Aiker, the one runaway the only slightly loaded series-wound motor prevented. The auxiliary exciter resistor 37 is intended to reduce the heating of the exciter winding 11 F of the Ground anchor 11 A separately, if the one to be lifted in each case

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Load is sufficient to ensure that the engine will stall
to prevent.

The switching on or off of the auxiliary excitation resistor 37 is controlled by the load sensing unit 82
(Fig. 3) controlled. When the motor is being lifted, the
The size of the motor current depends on the torque required to lift the load and thus on the size of the load
away. The load sensing unit 82 can therefore be exactly the size
determine the load to be lifted by the engine in that
it measures the motor current. The measurement of the motor current is done by the first measuring resistor 26, its output voltage
the input resistor 168 of the amplifier 169 is supplied
will. This positive voltage signal is amplified and inverted by the amplifier 169, so that the input resistor 171 of the amplifier 172 is input by the amplifier 169
negative voltage signal is transmitted.

A positive bias voltage is applied to the input resistor 180 of the amplifier 172 via the potentiometer 175
Voltage source 177 off applied. The negative voltage coming from the reference control circuit 81 is across the
Conductor 84, conductor 194, diode 192 and potentiometer 191 are supplied. The base of transistor 187 is across the
Conductor 238, diode 239, conductor 234 and resistor 236 are connected to a negative voltage source 237 with transistor 231 in the non-conductive state. The resulting negative bias of transistor 187 makes it conductive, thus the connection point
186 is grounded, so that of the resistors 182, 184, 185 only the resistor 182 virkt as an input resistor for the amplifier 172. The negative voltage applied to potentiometer 191 is applied to input resistor 182 via conductor 190.

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The negative voltage thus fed to the input resistor 182 is less than that at the input resistor 180th positive voltage, so that at the amplifier 172 there is a resulting positive bias. As long as the negative output voltage of the amplifier 169 is smaller when this resultant positive bias voltage, amplifier 172 provides a negative output voltage.

The amplifier 199 is a large gain inverting switching amplifier. Will the input of the resistance 197 If a positive voltage is supplied, a negative output voltage is obtained regardless of the size of the input voltage Fixed size generated. Conversely, a negative input voltage generates a positive output voltage of a fixed magnitude.

If the load to be lifted by the motor is too small to achieve that the input voltage applied across the wide range 171 exceeds the resulting positive bias of amplifier 172, the across the input resistor has 197 lying negative voltage has the consequence that the amplifier 199 a positive output voltage signal gives away.

That from reference control circuit 81 via conductor 84 transmitted negative voltage is present across conductor 194 the base of transistor 195, which is thereby biased into the conductive state. This makes resistor 205 bypassed so that the output voltage of the amplifier 199 is applied to a voltage divider containing only the resistors 202, 204.

The amplifier 211 is an integrating amplifier; he creates a time delay for the voltage to be applied to the base of transistor 219. The magnitude of this time

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Delay depends on the size of the input voltage to the amplifier and the resistance of the input resistor as well as the resistor 210 at a positive input voltage and the resistor 215 at a negative input voltage. The resistors 210, 215 are preferably chosen in such a way that the input resistance 210 results in a time delay which in comparison to the time delay generated by the input resistor 215 is small.

Since the output voltage of the amplifier 199 is positive, it is fed to the input resistor 210 via the diode 209. After a time delay, amplifier 211 applies a negative output voltage to the base of transistor 219. This bias does not allow transistor 219 to conduct. Its collector and accordingly also the connection point 221 are therefore positively biased via the resistor 227 by the positive voltage source 229. The base of transistor 231 is also positively biased so that it remains in the non-conductive state, its collector, as already described, being held at a negative voltage. The transistors 241 _t 243 whose base is negatively biased, are also non-conductive, so that neither the power winding 76 w of the first load-sensing relay

76 nor the working winding 77 w of the second load sensing relay

77 are excited.

Since the contacts 76 a (Fig. 1) of the first load sensing relay 76 remain open, the winding 36 w of the auxiliary exciter switch not be aroused. Thus, when the motor is lifting a small load 14, the auxiliary excitation resistance remains 37 connected in parallel to armature 11 A.

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If, however, a load exceeding the predetermined value is raised by the motor, then the motor through the first Measuring resistor 26 current flowing to such a size that the negative output voltage of the amplifier 169 (Fig. 3) exceeds the resulting positive input bias of amplifier 172 and amplifier 172 emits a positive output voltage. This positive output voltage switches when it is at the input resistance 197 of the amplifier 199 is applied, the output of the amplifier 199 to the fixed negative output voltage. This will applied to the voltage divider which still only contains the resistors 202, 204. The input voltage of the integrating amplifier 211 is now connected to the voltage divider tapped by the diode 214 and the input resistance 215 supplied.

After the time delay has elapsed, which is so great that a relay excitation due to transient currents is excluded is, the output of the amplifier 211 is so positive that the transistor 219 is brought into the conductive state. The collector of transistor 219 and accordingly the connection point 221 are now grounded, so that the transistor 231 becomes conductive. The collector of transistor 231 comes up to a positive voltage, so that the transistors 241 become conductive. The conducting state of transistor 243 has the consequence that the second load sensing relay 77 is actuated, which has no influence on during the lifting process the motor control circuit has. Because the transistor 241 becomes conductive, vdrd the first load sensing relay 76 is actuated. This has the consequence that the winding 36 w (Fig. 1) of the Auxiliary exciter switch 36 is energized, so that the contacts 36a opened and the auxiliary excitation resistor 37 from the armature 11 A be switched off.

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2244783

To ensure positive chatter-free operation of the first load sensing relay 76 is one regenerative pulse feedback circuit is provided which includes the resistor 227, the capacitor 224 and the Contains input resistance 225 and acts together with the integration amplifier 211. The Kontensator 224 lies between the input resistor 225 and the connection point 221. At the moment the transistor 219 is biased into the conductive state so that the connection point 221 reaches ground potential is from A negative voltage pulse is applied to the capacitor 22 4 at the input resistor 225. This will during an additional input variable which supports the output voltage of the amplifier 211 is generated for a short period of time and the conductive state of transistor 219 is maintained until the output voltage is no longer supported of the amplifier 211 has reached its maximum value.

When the auxiliary exciter resistor 37 is switched off from the armature 11 A occurs a decrease in the motor current, which is a corresponding decrease in that of the amplifier 169 amplified and inverted signal voltage fed to the input resistor 171 of the amplifier 172. This decrease in negative voltage would result in the circuit dropping the first load sensing relay 76, which would cause relay rattle. It is therefore necessary to check the sensitivity of the circuit after actuation of the relay 76 to prevent the auxiliary exciter resistor 37 from being switched on again. If the Transistor 231 becomes conductive, its collector is positively biased, as has already been explained. These positive voltage is not applied to the base of transistor 187 because it is blocked by diode 239. Through this

309813 / 08U

- 27 -

the bias is removed from transistor 187, which is thus blocked. The series connection of the resistors 184, 185 is now functionally parallel to the Resistor 182 switched; it reduces the input resistance and accordingly the gain for the Potentiometer 191 supplied negative voltage. The resulting positive bias of amplifier 172 is thereby further reduced, which also lowers the sensitivity level of the circuit. By correct Adjustment of the potentiometer 175, 191 brings about a change in the sensitivity, which is a correct one Compensation results when the auxiliary exciter resistor 37 is switched off and allows the circuit to adjust the auxiliary exciter resistor 37 as a function of a decrease in the current flowing through the first measuring resistor 26 one necessary for operation without an auxiliary exciter resistor 37 Turn the level back on.

If the load is reduced while the engine is running, for example if the load is released or a rope breaks occurs, it is necessary to quickly switch off the auxiliary excitation resistance 37 to switch back in parallel to armature 11 A, to avoid a runaway of the engine. The decrease in the current flowing through the first measuring resistor 26, the decrease corresponds to the engine load, acts via the amplifier 169, 172, as already explained, in the sense of Switching the output of amplifier 199 to full positive voltage. This voltage is across the diode fed to the input resistor 210, which causes the amplifier 211 to have a very short time delay (short enough to give a quick repetition after the transients have subsided) whereupon the output voltage of amplifier 211 drops to a level at which

309813/081 4

- 28 -

the transistor 219 and on the other hand the transistors 231, 241 and 243 are switched off. The winding 76 w is de-energized and the contacts 76 a open (Fig. 1) whereby the working winding 36 w of the auxiliary exciter switch 36 is de-energized is closed and the contacts 36 a and thus the auxiliary exciter resistor 37 is connected in parallel with the armature 11 A. will".

When adjusting the operating handle of the main switch 58 (Fig. 1) in a direction towards the OFF position takes the output voltage of the signal converter 79 and accordingly the reference control circuit 81, so that the output DC power of the AC-DC converter 44 reduced and the engine speed lowered. As soon as the operating handle reaches the OFF position, the main switch contacts 69, 71, 64 are opened, whereby the switches controlled by these contacts are de-energized v / earth. The AC-DC converter 44 is switched off; accordingly, the armature 11 A and the Excitation winding 11 F de-energized. This means that no more current flows through the brake winding 16 w, so that the brake 16 is applied and the engine comes to a standstill.

If the operating handle of the main switch 58 (Fig. 1) from the OFF position in one of the lowering operation of the engine corresponding direction is moved, the main switch contacts 67 are opened, while the main switch contacts 70, 64 closed to energize windings 28 w, 24 w. By energizing the main switch winding 24 w the contacts 24 a, 24 b closed. As a result of the excitation of the sinker winding 28 w via the now closed Hubcontacts 39 b closes the contacts 28 a, 28 c (see FIG. 27) while the contacts 28 b are open

309813 / 08U

- 29 _

in order to lock the lifting circuit.

In lowering mode, the motor is connected in shunt, the armature 11 A being fed by the first AC / DC converter 44 takes place via a circuit which the first AC-DC converter 44, the Overload relay winding 46 w, the conductor 45, the connection point 19, the conductor 27, the sink contacts 28 a, the conductor 34, the armature 11 A, the conductor 40, the dynamic sink contacts 41 a, the brake winding 16 w, the main contacts 24 a, the overload relay winding 25 w, the first measuring resistor 26, the Connection point 20 and conductor 47 contains. The dynamic one Brake resistor 31 is placed parallel to armature 11 A through dynamic brake contacts 32 a. The limit switch relay winding 30 w is parallel to the armature 11 A as during the lifting operation, so that it is from the first AC-DC converter 44 is fed and the contacts 30 a closes, and the contacts 30 b opens (compare Fig. 2). The actuation of the relay 30 takes place and the speed of the armature 11 A has increased so far that the Back EMF has reached a value that allows the Winding 30 must apply sufficient excitation voltage.

The field winding 11 F is supplied by the second AC-DC converter 49 excited by a circuit which the second AC-DC converter 49, the conductor 50, the field winding 11 F, the brake winding 16 w, the main contacts 24 a, the overload relay winding 25w, the first measuring resistor 26, the connection point 20, the conductor 51 and the second measuring resistor 52 contains. The speed of the now in the shunted llotors is by the first AC-DC converter 44 to the armature 11A

- 30 -

309813 / 08U

and determines the voltage applied to the field winding 11F from the second AC-DC converter 49.

When the operating handle of the main switch 58 is moved in the lowering direction, the signal converter 79 sends a positive output voltage is generated and fed to reference control circuit 81 via conductor 80. This positive tension is transmitted by diode 105 (FIG. 2) and blocked by diode 94 so that it is only connected via conductor 104 the lowering condition circuit 106, the input resistance of the amplifier 108, the input resistance 109 of the amplifier 110 and via the conductor 111 at the inputs of the amplifier 113 lies.

The lowering condition circuit 106 supplies a fixed negative voltage output signal as a function of the positive input voltage via the conductor 67 to the first ignition circuit 88, via the conductor 89 to the second ignition circuit 91 and to the input resistance 114 of the amplifier 113.

The amplifier 108 sums the positive input voltage with one from the voltage source 117 to the input resistor 116 applied negative bias voltage and generates a negative output voltage, the size of which increases with the output voltage of the signal converter 79 increases. This negative Voltage is applied to input resistor 119 of amplifier 120 and with one of input resistor 122 of the positive bias applied to the voltage source 124 is summed. Since the dynamic brake contacts 32 c are open, the transistor 129 is switched off, while at the input resistor 125 of the amplifier 120 a bias voltage of the negative voltage source 157 is located. This bias is so great that the amplifier 120 is independent of the output

309813 / 08U

- 31 -

Voltage of the amplifier 108 generates a positive voltage. This positive coming from amplifier 120 Voltage is blocked by diode 131, so that until the dynamic brake contacts close 32 c the actual output of amplifier 120 is zero.

The amplifier 110 generates a negative output voltage / which is proportional to its positive input voltage. The input voltage of the amplifier 110 and thus also its output voltage are limited by the fact that the amplifier through the diode 136 with the the transistor 137 and the voltage limiting circuit containing the resistor 139 is connected. If both contacts 30 b, 32 c are open, the potentiometer 141 is between one positive voltage source 142 and / via the base-emitter circuit of transistor 167, the earth. The base of the transistor 137 is thus held at a positive voltage, which has a size determined by the respective setting of the potentiometer 141 and in turn over the base-emitter circuit of transistor 137 is used to reverse bias the diode. The output voltage of the signal converter 79 * which does not exceed this counter bias and is preferably so great that it does not affect the engine speed, is at the input resistor 109 of the amplifier 110.

If one of the contacts 30 b, 32 c is closed, since the contacts 28 c closed during the entire lowering operation the negative voltage source 150 via the diode 146 or the diode 147 to the connection point 145 connected, causing the voltage drop across the potentiometer 141 is enlarged. This reduces the voltage at the base and at the emitter of transistor 137 to a fourth,

309813/0814

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which is also determined by the setting of the potentiometer 141, while that of the input resistance 109 of the amplifier 110 lying voltage to a value is limited, which is substantially equal to the emitter voltage of transistor 137. So if either the Limit switch relay contacts 30 b or the dynamic brake contacts 32 c are closed, the negative output voltage of the amplifier 110 is limited to a value which is determined by the setting of the potentiometer 141 is.

The negative output voltage of amplifier 110 is present through conductor 159, diode 160, and conductor 132 the input resistance 133 of the amplifier 96. Since there are no further input voltages at the amplifier 96 during lowering operation, its output voltage is proportional the input signal; it is supplied to the first ignition circuit 88 so that the first AC-DC converter 44 the tension on the armature 11 A increases when the operating strap of the main switch 5 8 is further adjusted in the lowering direction.

The excitation of the field winding 11 F is through the Output of amplifier 113 controlled. The input voltage of the amplifier 113 is supplied from three sources. One constant negative input voltage is fed from lowering condition circuit 106 to input resistor 114. A negative signal, which is proportional to the current flowing through the field winding 11 F, is from the second Measuring resistor 52 fed via conductor 85 to the inverter amplifier 162, from which a positive voltage is applied to the Input resistance 164 of amplifier 113 is applied.

309813 / 08U

- 33 -

This voltage is a feedback input voltage which helps ensure proper energization of the Ensure excitation winding 11 F. The output voltage des .Signalwandler 79 is via-the conductor 111 to the Input resistance 112 of the inversion input of amplifier 113 and via potentiometer 166 to the non-inversion input of amplifier 113 is applied.

When both the dynamic brake contacts 32c and the limit switch contacts 30b are open, the base of the transistor 167 connected to the junction 145 is positively biased so that the transistor 167 becomes conductive and the non-inverter input of the amplifier 113 is connected to ground and that of the signal converter 79 voltage coming via conductor 111 is only present at the inverter input. The fixed negative voltage of the lowering condition circuit 106 is so large that the output voltage of the amplifier 113 gives a maximum output voltage of the second AC-DC converter 49. In this way, a maximum excitation of the field winding 11 F is generated, which results in the minimum lowering speed of the motor. When the operating handle of the main switch 48 is moved further in the lowering direction, the positive output voltage of the signal converter 79 increases; it is combined with the fixed negative voltage of the lowering condition circuit 106 to form an output voltage which reduces the voltage across the field winding 11F. The input voltage supplied by the second measuring resistor 52 serves as a feedback signal to support the stabilization of the excitation of the excitation winding 11 F _f

309813/0814

- 34 -

Armature 11 A to while the excitation of the field winding 11 F is weakened to thereby achieve an increase in the engine speed.

The relatively high resistance value of the insulation resistance 22 (Fig. 1) allows a substantially separate excitation and control of the armature 11 A and the Excitation winding 11 F, while at the same time an electrical Connection between the armature 11 A and the excitation winding 11 F maintains, so that a dynamic sinking loop results, which acts in a dynamic emergency braking in the event of a malfunction. The dynamic sink loop contains the anchor 11 A, the limit switch contacts 15 b, the insulation resistance 22, the. Excitation winding 11 F, the conductor 40 and the dynamic countersunk contacts 41 a.

The dynamic braking resistor 31 (Fig. 1) must be parallel to the armature 11 A in order to be able to operate under heavy load conditions to maintain small lowering speeds. The dynamic braking resistor 31 is speed-limiting; it must therefore be switched off at high speed, so that only the dynamic lowering loop in the circuit is effective remain. The pronounced change in speed that occurs when the dynamic braking resistor 31 is switched off from the armature 11 A can occur, is in some applications the Stroke control undesirable .. The control circuit according to the invention therefore has provisions for switching off the dynamic braking resistor 31 hit by the armature 11 A without any significant change in speed, independently on the size of the respective lowered load. This is done by choosing a dynamic braking resistor 31 and

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309813/0814

an insulation resistor 22 of corresponding size and in that the dynamic braking resistor 31 is _{switched off at a predetermined value of the I:} lotorstromes and the output voltages of the AC / DC converter 44, 49 are adjusted in such a way that the speed change that normally occurs at the moment the dynamic braking resistor is switched off

31 would occur, is compensated.

When the operating handle of the main switch 58 is moved to the range of the average lowering speed, the main switch contacts 73 are closed, so that the dynamic brake switch winding 32 w can be excited via the second load sensing relay contacts 77 a and the limit switch relay contacts 30 a. If the limit switch has not been operated, the contacts 30 a are closed, äo that the excitation of the winding

32 w depends on the position of the contacts 77 a. In this way, the disconnection of the dynamic braking resistor 31 can be controlled by the load sensing unit 82.

The load sensing unit 82 switches off the dynamic braking resistor 31 from the armature 11 A, as well as via the first one Measuring resistor 26 a predetermined value of the motor current is determined. Since the first braking resistor 36 in the between the brake winding 16 w and the connection point lying part of the working circuit, both flow the armature current and the excitation current through the first measuring resistor 26, so that the sum of the currents of the AC-DC converter 44, 49 is measured.

- 36 309813 / 08U

The positive voltage signal from the first measuring resistor 26 is transmitted via the conductor 83, as in the case of the lifting operation the input resistor 168 of the amplifier 169 (Fig. 3) fed to the a negative voltage signal to the Input resistance 171 of amplifier 172 applies. The amplifier 172 combines this signal with the positive one Input voltage from the potentiometer 175 .. during the The lowering process becomes the input of the lift condition circuit 100 (Fig. 2) blocked by the diode 94 so that over the conductor 84 no voltage signal can be transmitted and accordingly no input voltage from the potentiometer 191 goes to amplifier 172.

The amplifier 172 is similar to the stroke operation until the negative. Output voltage of the amplifier .169 the positive bias, a negative output

liat
voltage, which results in the amplifier 199 delivering a fixed positive output voltage. This voltage, inverted by the amplifier 211, forms a negative bias voltage for the transistor 219 so that the load sensing relays 76, 77 are not energized. However, as soon as the negative output voltage of the amplifier 169 exceeds the positive bias voltage of the potentiometer 175, the output voltage of the amplifier 172 becomes positive, whereby the amplifier 199 is switched over in such a way that it emits a fixed negative output voltage.

Since no input voltage is fed from the reference control circuit 81 via the conductor 84, the Transistor 195 is not conductive, so that the voltage divider to which the output voltage of amplifier 199 is applied comprises three resistors 202,204,205 and the amplifier

• 309813 / 08U

- 37 -

a larger voltage is supplied than was the case during the lifting operation. This increased input voltage reduces the time delay caused by the integrating amplifier 211 to an interval the length of which is appropriate for the lowering operation. The input voltage to the amplifier 211 is over the diode 214 is applied to the input resistor 215, which creates an appropriate time delay, after which a voltage sufficient to ground the collector of the transistor 219 is applied to the base of the transistor 219, whereby the transistor 231 is biased into the conductive state and generating a short negative input pulse in the regenerative pulse feedback circuit in the manner already described.

. As a result of the conductivity of the transistor 231 received whose collector a positive voltage, which biases the transistor 2 43 into the conductive state and the zv / side load sensing relay winding 77 w energized. The transistor 241 is also biased into the conductive state; he excites the first load sensing relay winding 76 w. However, since the contacts 76 a are in the lifting part of the control circuit, the Actuation of this relay has no effect on the circuit during lowering operation.

When the contacts 77 a are closed (Fig. 1) the dynamic brake switch winding 32 w is excited, whereby the contacts 32 a open v / ground and the dynamic braking resistor 31 is switched off from the armature 11 A, so / ie the dynamic auxiliary brake contacts including the contacts 32 d in the load sensing unit 82 (Fig. 3) are closed. As when switching off the dynamic braking resistor

309813/081/4

- 38 -

from the armature 11 A no significant reduction of the motor current occurs, the contacts 32 d close a holding circuit for the winding 77 w, which the positive voltage source 247, winding 77w, conductor 249, contacts 32d and negative voltage source 250, contains. This holding circuit holds the excitation state of the winding 77 w independently of that by the first measuring resistor 26 flowing Stroin upright until the dynamic brake switch winding 32 w is de-energized by hand, that the operating handle of the main switch 48 in the slow gear - Senlc range is adjusted, whereby the Main switch contacts 73 open v / earth.

When switching off the dynamic braking resistor 31 the output voltage supplied from the reference control circuit 81 to the igniter circuits 88, 91 must be used to prevent a significant change in the lowering speed compensated v / earth. If the values of the dynamic braking resistor 31 and the insulation resistance 22 are correctly selected, When lowering with the dynamic braking resistor, the speed range of the motor overlaps the lowering speed range of the Motor without dynamic braking resistor regardless of the respective load on the motor. At within this overlap area lying speeds can therefore, if the engine speed is simultaneous with the change in operation is regulated wisely, the dynamic braking resistor 31 can be switched off without causing any significant change the hotord speed would be conditional. With increasing engine load, when the dynamic is switched off, it decreases Braking resistor 31 resulting corresponding increase in speed proportionally with the load. It must therefore Precautions are taken to reduce the voltage at the armature 11 A by lowering the output voltage of the reference control

309813/0814 -39-

circuit 81 for the first ignition circuit 88 and amplification of the excitation of the excitation winding 11 F by enlarging it the output voltage of the reference control circuit 81 for the second ignition circuit 91 to achieve such that the otherwise normally occurring change in speed is prevented.

As already explained earlier in connection with FIG. 2, the corresponding positions of the is at low speeds Main switch 58, the dynamic brake contacts 32 c are open, the effective output of amplifier 120 is zero so that only that supplied by amplifier 110 negative output voltage is supplied to amplifier 96. As the output voltage of the signal converter 79 increases, the output voltage of the amplifier 110 also increases, causing a corresponding increase in the lowering speed and the motor current. At a predetermined Value of the current flowing through the first measuring resistor 26, the load sensing unit 82 actuates the second load sensing relay 77, so that this is the dynamic braking resistor switch off. By operating the dynamic brake switch 32, the contacts 32 c are closed and the voltage drop on the potentiometer 141 increases, whereby the the voltage applied to the input resistor 109 of the amplifier 110 is clamped. The corresponding decrease in the Output voltage of the amplifier 10, which is connected to the first ignition circuit 88 via the amplifier 96, leads to a reduction in the voltage applied to the armature 11A. Closing the contacts 32 c also turns the transistor 167 switched off, so that the output voltage of the signal converter 79 is connected to the non-inverter input of amplifier 113 via potentiometer 166. This will partially the effect of the signal applied to the input resistor 112 nales to such an extent that the setting of the

309813/0814

- 40 -

Potentiometer 166 is determined while the output voltage of the amplifier 113 for the second ignition voltage 91 is increased, whereby an increase in the Excitation winding 11 F lying voltage occurs. Without further changes in the motor control circuit these voltage changes would cause a decrease in engine speed. However, if the potentiometer 141/166 are properly adjusted, compensate for the changes in the voltages on the armature 11 A and the field winding 11 F just the speed increase that would otherwise be when switching off the dynamic braking resistor 31 from the armature 11 A would have resulted.

When the motor is operating with a load attached to the load hook, the gage EMF of the motor increases so that the current flowing through the first measuring resistor 26 does not reach the value required to operate the load sensing unit 82 until the motor has a higher speed than reached with ¹ empty load hook. This requires a higher output voltage of the signal converter 79. The output voltage of the amplifier 110 v / ird is therefore increased above the value corresponding to the empty load hook and the output voltage of the amplifier 113 will have decreased below the value corresponding to the empty load hook before the contacts 32c for regulation of the initial suspicions have closed. The increase in the influence of the output voltages of the AC / DC converters 44, 49 with increasing load 14 precisely compensates for the increase in the influence on the motor speed at load 14 caused by switching off the dynamic braking resistor 31.

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309813 / 08U

The operation of the reference control circuit 81 during the automatic transition from dynamic braking to dynamic lowering operation should be based on 4-9 are illustrated in the diagrams of FIGS.

The function of the amplifier 110 is illustrated by the diagrams 4 and 5 each illustrating the output of amplifier 110 (Ä-110 in the diagram) in Dependence on the output size of the signal converter 79 (S / C in the diagram) shows. Points a and b indicate the minimum and maximum output sizes of the Signal converter 79 at which an automatic transition the mode of operation can be provided. The point c means the maximum output variable of the signal converter 79 during lowering operation. The point d gives the held Value of the output voltage of the amplifier 110 after closing the dynamic brake contacts 32 c. As can be seen from Fig. 4, which the operation when empty Load hook is illustrated, when the output size of the signal converter 79 reaches the minimum transition point a, the output of the amplifier 110 by a small value lowered to the recorded level d, at which it is for all larger values of the output variable des.Signalkonverters 79 remains.

Fig. 5 illustrates the function of the booster 110 during lowering with a load on the load hook. And the output voltage of the signal converter 79 reaches the specified at a value which is not sufficient to let from _# the load-sensing unit 82 effectively v / grounding of the motor, the current flowing through the first sense resistor 26 current counter electromotive force due to the increased.

309813 / 081A - 42 -

The output voltage of the signal converter 79 must therefore can be increased via point a, which corresponds to a corresponding increase in the output voltage of amplifier 110. When the current flowing through the first measuring resistor 26 is so great that the load sensing unit 82 is triggered, the output voltage of the amplifier 110 is lowered to the value specified at d and for all larger values of the output voltage of the signal converter 79 held at this value.

Although it would also be possible, in certain applications of the new lift control circuit, to adjust the speeds during the automatic transition from one mode of operation to the other simply by regulating the voltage applied to the armature 11 A, the voltage applied to the excitation winding 11 F must normally can be increased in order to match the speeds during dynamic lowering and dynamic braking. 8 and 9 are diagrams showing the output voltage of the amplifier 113 (A-113 in the diagram) as a function of the output voltage of the signal converter. 8 illustrates the operation for the amplifier 110 with an empty load hook as shown in FIG. At the minimum transition point a, when the load sensing unit becomes active , the output voltage of the signal converter 79 at the non-inverter input of the amplifier 113 raises the output voltage of the amplifier 113 up to the field weakening curve 254, whereby the voltage at the excitation winding 11 F

309813 / 08U

- 43 -

lying voltage is increased to a value which ensures that in the transition from one Operating mode on the other no significant speed change occurs.

Fig. 9 illustrates the operation of booster 113 during lowering with a load on the load hook; it corresponds to the function of the amplifier 110, as illustrated in FIG. If the the current flowing through the first measuring resistor 26 reaches the value required for the transition of the operating modes, is the output voltage of the amplifier 113 due to the increase in the output voltage of the signal converter 79 'dropped to a smaller value than in FIG. 8. When the operating modes are transitioned, this increased signal converter output voltage is connected to the potentiometer 166 Non-inverter input of amplifier 113 so that the field is amplified by a proportional amount to a corresponding point on the field weakening curve 254.

When closing the dynamic brake contact 32 c is transistor 129 is biased into the conductive state so that the negative input board is connected to ground and not at the amplifier 120. Thus, the only input voltages to amplifier 120 are just the fixed bias voltages from positive voltage source 124 and the negative output voltage of amplifier 108. Since the negative output voltage of the amplifier 108 decreases with increasing output voltage of the signal converter 79, cause the combined input voltages that the amplifier emits a negative output voltage, which increases with increasing Output voltage of the signal converter 79 increases.

309813/0814

- 44 -

The output voltages of the amplifiers 110, 120 become transmitted via the diodes 160, 131, so that only a transmission of the largest negative output signal to the amplifier 96 takes place. Pig. 6 illustrates the output voltage of amplifier 120 (A-120 in the diagram) as a function of the output voltage of the signal converter 79. Until the contacts 32 c close, the amplifier 120 has a positive output voltage, which can have any size and is blocked by the diode 131, so that there is actually a zero output. When the contacts 32 c close, the amplifier 120 becomes a negative output voltage generated, which can therefore not be transmitted by the diode 131 because they are not is greater than the output voltage of amplifier 110, whose output voltage is clamped at the specified point d until the output voltage of the signal converter 79 exceeds the value at d. The result of the combined output voltages of the amplifiers 110, 112 The output voltage resulting from the diodes 160, 131 to the amplifier 96 thus essentially follows the 7 plotted curve, which the input voltage of the amplifier 96 (Λ-96) as a function of the output voltage of the signal converter 79 indicates. The voltage applied to armature 11 Λ during lowering operation of the motor is substantially proportional to the input voltage to amplifier 96; it therefore also follows the curve Fig. 7.

The excitation of the excitation winding 11 F is, as already stated, by the output voltage of the amplifier 113 controlled. Before the contacts 32 c are closed, the output voltage of the amplifier 113 is reduced by one through the Curve 252 in FLg. 9 is reduced. After switching off the dynamic braking resistor 131 and the Turning off the transistor 167 but shifts the to the

309813/0814

- 45 -

Non-inverter input of amplifier 113 lying Output voltage of the signal converter 79, its output voltage on the curve 254 in Fig. 9. In this way a proper field weakening is achieved in the entire lowering range of the motor.

When it is necessary to quickly achieve a high lowering speed and that of switching off the dynamic Brake resistor 31 resulting from the speed change is unimportant is, the operating handle of the main switch 58 can be adjusted in the lowering direction until the main switch contacts 72 close. This closes an excitation circuit of the winding 32 w, whichever is the second load sensing relay contacts 77 a bypasses, so that the dynamic braking resistor 31 is immediately switched off by the armature 11 A, as long as the limit switch relay contacts 30 a are closed.

When the operating handle of the main switch 58 is moved to the OFF position, the output voltage increases of the signal converter 79. Thereby occur a decrease in the voltage applied to the armature 11 A and a Reinforcement of the field of the excitation winding 11 F. if the operating handle reaches the slow speed lowering range, the contacts 73 are opened and the dynamic braking resistor 31 is again parallel to the armature 11A switched. The dynamic brake contacts 32 c (Fig. 2) now open, so that the 11A lying on the armature Voltage is now determined by the output of amplifier 110 and the excitation of the excitation winding 11 F now follows the curve 252 in FIG. If the main switch is in the OFF position - then the contacts 70, 74 open and the! "J AC DC converter 44, 49 switched off, so that the armature 11 A and the excitation winding 11 F deenergized / grounded. Through the brake winding 16 w flows

309813 / 08U

- 46 -

no more electricity; brake T6 is therefore applied. on this will stop the engine.

If during the lifting operation of the motor, the load 14 was raised to such an extent that the limit switch 15 was actuated, the contacts 15 a, 15 b closed and the contacts 15 c, 15 d opened. The contacts 15 c, 15 d in the hub power circuit separate the armature 11 A and the excitation voltage 11 F from the operating voltage. At the same time, a dynamic brake loop is established to stop the armature, which connects the armature 11 A, the conductor 40, the conductor 42, the limit switch contacts 15 a, the two stroke contacts 39 a, the excitation winding 11 F, the conductor 27, the limit switch resistor 29 , which includes limit switch contacts 15b and conductor 34. By operating the limit switch 15, the excitation voltage is removed from the limit switch relay winding

30 w switched off, so that the contacts 30 a open and the auxiliary contacts 30 b (Fig. 2) are closed until the limit switch 15 returns to its original state.

When lowering with the limit switch 15 activated, the armature 11 A and the excitation winding 11 F are grounded the same Circuit like excited without actuation of the limit switch 15 because the excitation circuits do not make the limit switch contact «* 15 c, 15 d included. The dynamic braking resistor 31 is connected in parallel to the armature 11A. Since the limit switch relay contacts 30 a in the main switch 58 are open, the dynamic brake relay winding 32 w can when lowering with the limit switch activated 15 are not excited, so that the dynamic braking resistor

31 can not be switched off by the armature 11 A until the limit switch is back in the original Condition was returned.

309813 / 08U

- 47 -

By closing the limit switch relay contacts 30 b (Fig. 2), the output voltage of the amplifier 110 is clamped without affecting the output voltage of amplifier 120 would be enabled. Since the dynamic brake contacts 32 c not closed as long as can be before the perimeter switch in the original State has been returned, the output voltage of the amplifier 120 remains clamped, so that the motor is independent of the output voltage of the Signal converter 79 only in its slow speed range can lower.

When the limit switch 15 returns to its original state is returned, the limit switch relay 30 is actuated, thus normal operation of the Reference control circuit 61 is restored.

It goes without saying that in certain applications the new circuits it may be possible to adapt the 'speeds during the automatic transition from one Operating mode to achieve the other without increasing the field of the excitation winding 11 F at the transition point. The reference control circuit can thereupon in a simple manner by adjusting the potentiometer 161 until the connection. the non-inverter input of amplifier 113 to ground to be set-.

If desired, the reference control circuit'81 can also be equipped with a current limiting circuit of a type known per se in order to reduce the output of the first AC-DC converter 44 limit incoming current. From one between the connection point 20 and the first AC / DC converter 44 lying measuring resistor can emit a control signal, in which case

309813/081 U

- 48 -

22U763

the first measuring resistor 26 can be omitted. The signal for actuating the load sensing unit 82 can then achieved by combining the output voltages of the two measuring positions.

Although the control system of the invention has been described in connection with a stroke controller _f it is with other motor controls useful in which the radiation emanating from a load force resists the rotor rotation in one direction of rotation (non-spinning load) and (supports the rotor rotation in the other direction of rotation in generally a spinning load).

- 49 -

309813 / OeU

Claims (22)

Sponsorship claims 1.J Control circuit for one from an AC power source fed DC series rotor, in which the speed of the motor can be selected by an assigned main switch in a first switching range in one direction of rotation and in a second switching range in the other direction of rotation can be regulated and in the case of the signal generating means when the main switch is in the first switching range a Voltage of a first polarity and, when the main switch is in the second switching range, a voltage of one second polarity can be generated, characterized / that it has two input side to the alternating current source (L1-L2-L3) connected, controlled AC-DC converters (44,49), the control inputs of which via a reference control circuit (81) are connected to the signal generating means (79) and of which when a voltage occurs of the first polarity at the signal generating means (79) only the first AC / DC converter (44) emits a direct current output and when a voltage of the second polarity occurs at the signal generating means (79) both AC-DC converters (44,49) deliver a direct current output and that the armature (11 A) and the for this purpose in series excitation winding (11 F) with the main switch (58) in the first switching range to the Output terminals of the first AC-DC converter (44) are connected and in the second switching range standing main switch (58) of the armature (11 A) with the output terminals of the first AC / DC converter (44) and the field winding (11 F) connected to the output terminals of the second AC-DC converter (49) are and by one between the anchor (11 A) and the Excitation winding (11 F) series-connected insulation resistance (22) was a connection between the excitation 309813/0814 the excitation winding (11 F) and the one on the armature (11 A) lying voltage is established when the main switch (58) is in the second switch position. 2. Control circuit according to claim 1, characterized in that that they switch means (45,46w, 17,21a, 15c, 15d, 39a, 16w, 24a, 25w, 26,47 or 45,46w, 27,28a; 34,4O, 41a, 16w, 24a, 25w, 26,47) through which the armature (11 A) and the with it in series lying excitation winding (11 F) or just the armature (11 A) to the output terminals of the first AC / DC converter (44) can be connected and that the excitation winding (11 F) with the output terminals of the second AC-DC converter (49) connecting switching means (50,16w, 24a, 25w, 26,51,52) the polarity of the the voltage across the field winding (11 F) is kept the same for both switching ranges of the main switch (58), while the voltage across the armature (11 A) is in the first switching range standing main switch (58) a first polarity and standing in the second switching range Main switch (58) has a second different polarity. 3. Control circuit according to claim 1 or 2, characterized in that that when the main switch is in the first switching range, the motor is attached to one of the load hooks Load is not spun and that with the main switch in the second switching range, the motor cuts through the load can normally be turned over. 4. Control circuit according to one of the preceding claims, characterized in that it is used to drive a hoist and the first switching range of the main switch the lifting range and the »wide switching range of the main switch is the lowering range. 309813/0814 - 51 - 5. Control circuit according to claim 4, characterized in that that they have an overload limit switch (15) with normally closed limit switch contacts (15c, 15d) has and the armature (11 A) and the excitation winding (11 F) in series with the output terminals of the first AC-DC converter (44) connecting switching means (45,46w, 17,21a, 15c, 15d, 39a, 16w, 24a, 25w, 26,47) when the main switch (58) is in the lift area, the Limit switch contacts (15c, 15d) included and the Armature (11 A) to the output terminals of the first AC-DC converter (44) and the field winding (11 F) with the output terminals of the second AC-DC converter (49) connecting switching means (45, 4Gw, 27,28a, 34,40,41a, 16w, 24a, 25w, 26/47 or 50, 16w, 24a, 25w, 26, 51,52) with the main switch (58) in the lowering area independent of the limit switch contacts (15c, 15d) are. 6. Control circuit according to one of the preceding claims, characterized in that it has an electromagnetic releasable engine brake. (1.6) up / down, its release winding (16w) in series with the armature (11 A) and the excitation winding (11 F) and when the main switch (58) is in the first switching range due to the direct current output only des first AC / DC converter (44) and when the main switch (58) is in the second switching range the DC output of both the first and second AC to DC converters (44, 49) is fed. 7. Control circuit according to one of the preceding claims in which the output voltage of the signal generating means can be changed by the main switch, characterized in that that the Bdzugsteuersehaltung (81) depending on a Change of the output voltage of the first polarity of the 309813/0814 - 52 - - 52 - 22U763 Signal generating means (79) a change in the output direct current of the first AC-DC converter (44) and in response to a change in voltage of the second polarity of the signal generating means (79) a change in the output direct current of both the first and the second AC-DC converter (44,49) causes. 8. Control circuit in particular according to one of the preceding claims, characterized in that when in Peihe to the excitation winding (11 F) on the output small of the first AC-DC converter (44) connected Armature (11 A) parallel to the armature (11 A) is an auxiliary exciter resistor (37) which is controlled by Current measuring means (26,82) at a predetermined value of the Output direct current of the alternating tr om direct current converter (44) can be switched off from the armature (11 A). 9. Control circuit according to claim 8, characterized in that the current measuring means (26, 82) are one in the motor circuit have lying current measuring element (26), the one for the size of the equalizing current of the AC-DC converter (44,) emits a characteristic signal and are connected to the load sensing means (82) through which, as a function the auxiliary excitation resistor (37) can be switched off from a predetermined size of the signal emitted by the current measuring element (.26) and as a function of a second predetermined magnitude of the signal emitted by the current measuring element (26) the auxiliary exciter resistor (37) can again be switched in parallel to the armature (11 A). - 53 - 3 0 9 fl IS / (1 10. Control circuit according to claim 9, characterized in that a bias signal through the load sensing means (82) is generated with the signal emitted by the current measuring element (26) by a with the current measuring element (26) associated comparison facility ■ (180,182, 172) is compared, which depends on the sign of the difference between the two compared signals, a voltage emits one or the other polarity and is connected to a time delay device (21Ο, 215, · 211), which according to An output voltage emits expiry of a set period of time through which switching means (76) cannot be actuated in the sense of connecting or disconnecting the auxiliary excitation resistor (37). 11. Control circuit according to claim 10, characterized in that the time delay device (210,215,211) an amplifier (211) ', the input of which with the Output connected by a first Kontensator (216) and an input resistance (210) yielding a time delay of a predetermined first duration to the one harvester and a upstream of the second input resistance (215) which results in a time delay of a predetermined second duration are and that the voltage of the rectifier (209,214) a polarity of the comparison device (180,182,172) to the first input resistance (210) and the voltage of the other polarity of the comparison device (180,182,172) can be applied to the second input resistor (215). 12. Control circuit according to claim 11, characterized in that that the time delay device (210,215,211) having switching means (219) connected to the output of the amplifier (211), which when the voltage is applied a polarity on the time delay device (210,215,211 309813 / 08U conductive. and when the voltage of the opposite polarity is applied to the time delay device (210,215,211) are blocked and which are also connected to a voltage source (229) of the other polarity and that between the voltage source (229) and the input of the amplifier (211) is a second Kontensator (224), which is with conductive switching means (219) via the amplifier (211) can discharge. 13. Control circuit according to one of claims 10-12, characterized in that by a between the switching means (76) and the comparison device (180,182,172) lying switching element (231) with parallel to the armature (11 Λ) lying auxiliary exciter resistor (37) a bias signal a first predetermined value and, when the auxiliary exciter resistor (37) is switched off, a bias signal a second predetermined size can be delivered. 14. Control circuit according to one of claims 8-13, characterized in that the reference control circuit (81) has an amplifier (96) with two with the amplifier input connected input resistors (95,101), of which the voltage of certain polarity of the first Signal generating means (79) can be applied and the second connected to a voltage source of the corresponding polarity and that between the two input resistors (95,101) there is a voltage divider (102) whose tapping point (102 w) is due to a voltage of a predetermined magnitude. 15. Control circuit in particular according to one of the preceding Claims, characterized in that with the output terminals of the first AC-DC converter (44) connected armature (11 A) and with the output terminals of the 309813 / Q8U - 55 - second AC-DC converter (49) connected Excitation winding (11 F) parallel to the armature (11 A) a dynamic braking resistor (-31) is connected "and that the disconnection of the dynamic brake resistance (31) by current measuring means (82) at a predetermined size of the output DC power of the first and second AC-DC converters (44,49) can be triggered. 16. Control circuit according to / claim 15, characterized in that /the " " that the current measuring means (82) have a current measuring element (26), the one for the magnitude of the output DC current of both the first and the second AC-DC converter (44,49) emits a characteristic signal and are connected to the load sensing means {82) through which, depending on a predetermined size of the signal emitted by the current measuring element (26), the disconnection of the dynamic braking resistor (31) is controllable. 17. Control circuit according to claim 16, characterized in that that the load sensing means (82) are connected to the current measuring element (26) connected comparison device (180,182,172) which compares the signal emitted by the current measuring element (26) with a bias signal of a predetermined magnitude and depends on it from the sign of the difference between the two signals being compared, a voltage of one or the other polarity and that the comparison device (80,182,172) a time delay device (210,215,211) is connected, the nij.ch Zvblauf a predetermined delay time span emits an output voltage through which via switching means (77) the dynamic braking resistor (31) can be switched off. - 56 3 0 9 8 1 3 / (l 8 1 Z 18. A control circuit according to claim 17, characterized in that the time delay means (210,215,211) comprises an amplifier having its input connected to the output by a first accounts crystallizer (216) ¹ and a first, a time delay of a predetermined first duration resultant input resistor (210) and a second input resistor (215) giving a time delay of a predetermined second duration is connected upstream and that the voltage of one polarity of the comparison device (180, 182, 172) at the first input resistor (210) and the voltage of the other polarity of the comparison device ( 180,182,172) can be applied to the second input resistor (215). 19. Control circuit according to one of claims 15-18, characterized in that the reference control circuit (81) by a control intervention when the dynamic braking resistor (31) is switched off, a change in speed is more significant Size of the engine prevented. 20. Control circuit according to claim 19, characterized in that that the reference control circuit (81) has a first output side amplifier (96) connected to the first AC-DC converter (44), a second amplifier (120) from its output as a function of an input voltage received by the signal generating means (79) Output voltage can be transmitted to the first amplifier (96) and has a third amplifier (110), of which Output as a function of an input voltage supplied by the signal generating means (79), an output voltage the first amplifier (96) can be fed and that by switching means (129) in parallel with the armature (11 A) horizontal dynamic braking resistor (31) the output 3 0 9 8 1 3/0 fl U ~ 57 _ Voltage of the second amplifier (120) and by other switching means (137) when the dynamic Braking resistor (31) the output voltage of the third Amplifier (110) can be limited and through between the input of the first amplifier (96) and the output of the second and third amplifier (120, 110) lying switching elements each have the greater output voltage of the first Amplifier (96) can be fed. 21. Control circuit according to claim 20, characterized in that that the reference control circuit (81) has a fourth output side with the control input of the second AC / DC converter (49) connected and having an inverting and a non-inverting input Amplifier (113) contains, at its inverting input, the voltage of the first polarity of the signal generating means (79) can be applied, a voltage source supplying a voltage of the first polarity of opposite polarity (106) and also a part of the output voltage the signal generating means (79) are connected to the resistor (166) transmitting the non-inverting input and that by switching means (167) the voltage of the signal generating means (79) when the dynamic Bremsv / iderStandes (31) parallel to the armature (11 A) of the non-inverting input of the fourth amplifier (113) can be derived. 22. Control circuit according to claim 21, characterized in that never another in series with the output of the second Wechseltrom-Gleichctronikonverters (49) lying Stroniiacß member (52), which is connected to the reference control circuit (81) is connected by which one for the size of the output equilibrium of the second half-current DC converter (49) characteristic voltage can be applied to the non-inverting input of the fourth amplifier (113). 3 0 9 oil! / 0 8 1 /,