SU1394387A1 - D.c. electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in devices for stabilizing the rotor speed of an electric motor. The purpose of the invention is to reduce the start-up time and increase the accuracy of stabilization. The drive contains serially connected clock pulse generator (GTI) 3, gated amplifier (SU) 4, shaper 5 sawtooth voltage, discriminator 6 and key amplifier 2, the output of which is connected to the electric motor (ED) 1 and another SU 4 The GTI 3 is provided with an additional input connected to the output of the sample storage device (VHF) 7. The signal from the output of the SU 4 is fed to the information input of the VHF 7, the output of which goes to the control input of the GTI 3, increasing its frequency. With an increase in the angular velocity of the rotor ED 1, the voltage at the output of the VHH 7 increases, while the steepness of the conversion of the emf to the pulse duration increases and the accuracy of stabilization increases. 2 Il. (L

Description

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11394387

This invention relates to electro. technology and can be used in devices that require maintaining a stable rotor speed of an electric motor.

The purpose of the invention is to reduce the start-up time and to increase the accuracy of stabilizing the rotational speed of an electric motor.

FIG. 1 shows a structural diagram of the electric drive, FIG. 2, timing diagrams for steady state and starting mode of the electric drive.

The DC electric drive contains an electric motor 1, the root winding of which through a key amplifier 2 is connected to a power source and in series connected a 3-clock pulse generator, a gated amplifier 4, a saw-head driver 5 and a discriminator 6, the output of which is connected to a control input key amplifier 2. The second input of the discriminator 6 is connected to the input of the gated amplifier 4, the second input connected to the output of the key amplifier 2.

In addition, the electric drive contains a sample-storage device 7, one input of which is connected to the generator output 3 clock pulses, and the second - to the output of gated amplifier 4. The generator 3 clock and 35 pulses is provided with an additional input connected to the output of sample-storage 7 .

The drive works as follows .40

The clock pulse generator 3 generates pulses 8 (Fig. 2), which arrive at the control input of the gated amplifier 4 and at a time when it is compared with the threshold 10 of the discriminator 6, which is triggered and turns on the key amplifier 2. The higher the rotor speed of the electric motor 1, the greater its electromotive force, the higher the voltage 9 at the output of the sawtooth driver 5 and, consequently, the shorter the pulse duration 11 (Fig. 2) at the output of the discriminator 6, during which p e a supply voltage for electron rodvigatel 1. Thus, a stabilization impl stvl Vera scheni rotor speed of the motor 1.

The signal from the output of gated amplifier 4 is fed to the information input of the sample-storage device 7, to the control input of which a clock pulse 8 is received from the generator. Since the information in the device 7 is recorded only under the influence of a control pulse 8 (sampling signal on its output in the storage mode will be equal to the signal at the output of the gated amplifier 4 at the time of the end of the clock pulse 8, i.e. the electromotive force (and is proportional to the rotor speed of the electric motor 1). Borki-storage is fed to the control input of the generator 3 clock pulses and increases its frequency.

At the beginning of the start-up, the angular rotational speed of the rotor is close to zero and the frequency of the generator 3 is minimal. At the same time, the duration of the clock pulse 8 (Fig. 2) is sufficient to accurately measure the speed (electrically transient process in the core circuit 30

the equal input of the discriminator 6 mouth-45 sings fade out), which provides

when a zero signal is turned on at its input, which disconnects the key amplifier 2. Since at this moment the external voltage from the electric motor 1 is removed, a voltage arises on it equal to the electromotive force, which is proportional to the rotation frequency of the rotor. This voltage, through a powered gated amplifier 4, is fed to a sawtooth voltage driver 5. At the end of the clock pulse 8, the voltage 9 (Fig. 2) at the output of the driver 5, the saw-tooth voltage begins to linearly decrease.

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and at the moment of comparing it with the threshold 10 of the discriminator 6, the latter is triggered and switches on the key amplifier 2. The higher the rotor speed of the electric motor 1, the greater its electromotive force, the lower the voltage 9 at the output of the former 5 for saw voltage and, the shorter the pulse duration 11 (Fig. 2) at the output of the discriminator 6, during which the supply voltage is applied to the electric motor 1. Thus, the rotor speed of the electric motor is stabilized l 1.

The signal from the output of the gated amplifier 4 is fed to the information input of the sample-storage device 7, to the control input of which a clock pulse 8 from the generator 3 is received. Since the information in the device 7 is recorded only under the influence of the control pulse 8 (sample), the signal at its output in the storage mode will be equal to the signal at the output of the gated amplifier 4 at the moment of the end of the clock pulse 8, i.e. electromotive force (and proportional to the speed of rotation of the rotor of the electric motor 1). The output signal from the sampling-storage device 7 is fed to the control input of the generator 3 clock pulses and increases its frequency.

At the beginning of the start-up, the angular rotation speed of the rotor is close to zero and the frequency of the generator 3 is minimal. At the same time, the duration of the clock pulse 8 (Fig. 2) is sufficient to accurately measure the speed (electrical transient process in the core

minimum start time of the motor. With an increase in the angular velocity of the rotor of the electric motor 1, the voltage at the output of the sampling-storage device 7 increases, which causes an increase in the frequency of the generator 3 and a decrease in the duration of the clock pulses 8. This increases the steepness of the conversion of the electromotive force into the pulse duration 11 (Fig. 2) and most of all, with the accuracy of stabilization of the angular velocity of rotation of the rotor of the engine in a steady state. .

Claims (1)

Invention Formula A DC motor that contains an electric motor, the root winding of which is connected via a key amplifier to a power source, serially connected clock generator, a strobing amplifier, a sawtooth driver, and a discriminator whose output is connected to the control input of a key amplifier, and the second input - with the input of the gated amplifier, the second input connected to the output of the key amplifier, characterized in that, in order to reduce the start-up time and accuracy and stabilize the rotational speed, a sampling-storage device is introduced into it, the clock pulse generator is provided with an additional input for connecting to the output of the sampling-storage device, one input of which is connected to the output of the gated amplifier, and the second one - with the output of the clock pulse generator. FIG. 2