DE2053859A1 - Control circuit for direct current electric motors - Google Patents

Description

Control circuit for light current jiilektroiiiotore

For this registration, the priority is the corresponding British registration IMo. 52 d79 / 69 of October 28, 1969 claimed.

Jjie invention relates to a control circuit for Cr DC electric motors, such as those as battery-operated motors in battery-operated vehicles be used.

We already know Öteuerki'eise for ü-light current motors, where the current from a DC power source, such as a battery, is fed to the motor via a pulse control Thyristor arrangement are supplied. The, conditions of the Control by means of eiricu pulse generator are such, dati the üauptenergiezufuhr to the motor by changing the .frequency and / or the TaKtabutand ratio of the üenoratoriiüpulae can be varied.

EAD OBiGlNAL

109819/1374

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With such an arrangement, electrical deceleration or braking is achieved by switching on a reversing switch reached, which reverses the Peldwindungsansehlüsse. As a result of high emf being excited and accordingly of the currents, the field current becomes proportionate kept low, especially with hard or violent braking.

The invention is based on the object of a control circuit to create which the application of high currents of Ji'eld to the motor after actuating the reversing switch and before the motor has come to a standstill.

This object is achieved according to the invention achieved that a control circuit for the control of a DC switch, which current pulses from a Direct current source to the motor transmits, the pulses in their .frequency and / or ihx'em factual ratio in accordance with a control signal can vary, and a forward / backward holder with Intermediate "off" position provided sina, and that in addition, a pulse counter that is connected to deai Aiotorkreis is connected, is present, of the Sparinungaimpulae, that rest on the armature of the iwotor, enumerates

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BATH ORIGINAL

and that begins with its counting process vuii .Null whenever the forward / backward so holder is moved into or through the "off" position, and that finally switching means are provided, which then, when ^ he counters between the numerical value 1 ¹ JUlI and When the predetermined numerical value is in operation, the otroni value or the current range, which can be applied to the motor, is limited, while the full motor range is applied to the motor at other times.

further features and vortexes of the invention become described below with reference to the drawing. The accompanying drawing shows an example embodiment of the invention, and it means:

Fig. 1 is a graphical representation of a

Time tension diagram for the offices of the engine and

. 2 a shemematic bchaltbila des tax trip according to the invention.

m Fig. 1 shows how the voltage v ,. depending on

Ct

The speed of the motor armature drops over time or

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is applied in a pulsed manner. The first part of the graph marks the residual amount and shows the EMF generated when the forward / reverse switch is switched to the "off" position and the motor is still rotating forward. This "off" position α lies between the two dashed vertical lines. The first divisions shown in FIG. ¹ with curved symbolic lines S designate the forward position for Ji 1 and the rearward position for H. In parallel with armature A (Fig. 2) of the motor is a diode DI, the differential voltage polarity being such that the diode is reverse biased. Is the forward / reverse switch _b eht now in its rearward switching division on, whereby the electric field is reversed, and thus the polarity of the voltage to the armature reversed, so that the diode is biased in the forward direction as seen from the graph is. This condition continues until the drop in motor speed has reduced the armature current below the field current. At this point the field current pulses reverse the diode bias ratio and create voltage

impulses that drop across the armature. These impulses set j alternately and continuously positive and negative continue, as is evident from FIG. 1, until the motor switches to

BATH ORIGINAL _

109819/1 37

its rotational movement comes to rest, in order to then rotate in the opposite direction. In jig. I denotes the arrow interval Jj ¹ X) the forward movement and the arrow interval B the deceleration or deceleration of the rotary movement. The "stop" area is denoted by ^{S 1} I ^1. It is important that the motor essentially comes to a standstill before the full drive voltage is applied to it. The steady-state conditions of the motor can be indicated by the average armature voltage becoming negative, although an unusual DC level display can lead to confusion with the remaining amount or the differential voltage, because at low pulse rates the average voltage is very low. According to the present invention, this difficulty is overcome in that a pulse counting circuit is provided.

schematically ^l ig in Jj. As shown in FIG. 2, the motor has an armature α with an i ”which is reversible in its direction of travel ^; eiü t ^(1. The ut rom is supplied by a battery BT via a direct current switch J, which has a thyristor arrangement which emits current impulses, the frequency and duration of which are controlled by a control circuit. Jim Forward-ZReverse-switch J ) ¹ R controls the contact devices or push button relays RLJj ¹ and RLR,

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which together have the contacts HLFl and RLRl for interchanging the .Feldes ü ¹ · Parallel to the motor-ranker A is a diode Dl, which acts in a manner known per se. Voltage pulses falling across the armature A are sent to a counting circuit via the series resistor R4 and shunt Zefcner diode Zl, so that pulses with constant amplitude are present Capacitance, as well as the diode i> 2 and the resistor R5, so that the charge on the capacitor U2 increases with each pulse until the retention voltage of a transistor Tl is reached.

When the connection is closed and the container Fd is turned into the forward or backward division, the transistor Tl is in its operating state. Thus the impulses are applied to the AnK: er A of the iiaotor and the counting circle begins with its counting process. After e.me a predetermined number of bpannungsimpulseri has been given to the capacitor HZ , the reverse bias voltage is exceeded on a diode Dj5 and the transistor Tl becomes conductive and energizes dati lielaiü RLA.

As a result of the actuated contact KLA 1 there is a

BATHROOM OPTIQINAL

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1 0 9 8 1 9/1 3 7 U

Voltage across aem resistor B2 to transistor T2, which is thereby brought into the conductive state and discharges the capacitor C2 and holds this capacitor in the discharged state. In addition, the transistor T1 becomes conductive via the Kiderstand lil State held * The contact ELa 2 transfers the control voltage from its lower range to a higher one «. However, the higher control voltage range cannot be applied to the G-I calibration current switches were created until a predetermined one Number of pulses has been counted in the counting circuit, so that it is ensured that the motor is stationary or wira, before the higher voltage of the motor current can be created.

If the container J) ¹ Ji is moved from its forward position to the backward position or vice versa, the servant always passes an "off" position, so that the transistor Tl loses its operating voltage and the relay BLa aDfäiite. The control range of changed from its high to the low state, the low range being suitable for the deceleration or braking process *. After a predetermined number of pulses has again been counted, the iielais HLA is energized again, so that now the high control range is used

109819/1374

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got.

Instead of the electromagnetic relay reproduced in Mg. 2, a semiconductor relay or the like can also be used in an equivalent manner Wise application.

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Claims (7)

_ η claims 1.) Control circuit for controlling DC motors, characterized by a DC switch, which current pulses from a Direct current source delivers to the motor, the pulses in their frequency and / or in their pitch ratio changeable in accordance with exnem oteuersignal are, and where a forward / reverse switch with one lying between its two itfid positions "Off" position and one in the motor circuit above the Armature of the motor falling pulses counting counters are provided, the counting process starting from WuIl is always triggered when the forward / reverse switch moves into or through the "off" position becomes, and where transfer elements (change-over means) are present, which if the meter is in Counting operation between imll and a predetermined one Number is the voltage that is applied to the motor, reduce, but at other times it can be fully dropped over the engine. BATH ORIGINAL -ΐϋ- 1 0 9 8 1 9/1 3 7 U 2. Control circuit according to Anspaich 1, characterized in that that you are exercising aids when putting on the full Voltage to the motor resets the counter to 1ml1 and makes it ready for a new counting process holds, whereby the counting process is triggered by actuating the forward / backward switch, subald this is moved into / or through the "off" position. 3 control circuit according to claim 2, characterized in that that the pulse counter has a capacitor with a small capacity and one in the circuit lying capacitor has large capacitance that a diode is interposed between the two, wherein a shunt of the latter capacitor a jint charging transistor takes place, whose .Conductivity is then reduced if the transfer means the Allows full current to be applied to the motor. 4. Control circuit according to claim 3 »characterized in that j that the voltage drop across the capacitors of larger j capacity at a control of the transfer medium Relay is present. · J BATH ORIGINAL ^; - 11 1 Π 9 8 1 9/1 3 7 4 5. control circuit according to claims 4, characterized in that in the £ elaiskreis e ± n transistor and that the voltage applied to the capacitor with large capacitance is also applied to the base of the 'fransist ors via a diode, the predetermined number of pulses to be enumerated is reached when said capacitor has reached a voltage which corresponds to the threshold voltage of the diode and the transistor. 6. Control circuit according to claim 1 to 5, characterized in that the pulse counter with de ^ motor armature circuit Limiting means is connected so that the pulses supplied to the counter have a substantially constant Possess amplitude. 7. Control circuit according to claim 6, characterized in that the limiting means have a series of resistors and a bypass Zener diode. Patent attorney Seiler and Pfeiinmfr 1 0 9 8 1 9/1 3 7 h Blank page