SU497563A1 - Relay Controller - Google Patents

Description

comparator torch circuits are produced from a DC source 16. The emitters of the transistors are combined and connected to the source of the reference voltage 17, having the same polarity from the relative common wire as the source 16. The diode 18 together with the base-emitter junction of the transistor 6 forms the first a balanced voltage comparison circuit across a resistor 2 with an olon Uonof source 17. The second comparison circuit is formed by a diode 19 and the base-emitter junction of the transistor 7. The dividers 20, 21 and 22, 23 each of the comparison circuit sets the bias current from the source nickname of the collector power 16. The output winding 24 of the pulse transformer 10 through the aperiodic link 25, 26 and the diode 27 is connected to the control circuit of the output thyristor 28. The output thyristor 29 is controlled from the winding 30 via the aperiodic link 31, 32 and the diode 33. The output thyristors are powered pulsating voltage. The winding 34 of the transformer 10 through a resistor 35, a capacitor 36 and a neon lamp 37 is connected to the aperiodic feedback link 38, 39 of the regulator. The charge rate of the capacitor 39 feedback is determined by the resistor 35, and the discharge is determined by the resistor 38. The voltage from the output of the feedback link 38, 39 is fed to the input of amplifier 1. In the absence of an input signal (7v), the current at the output of amplifier 1 is also to zero. In this case, the bias current, specified in the first balanced comparison circuit, passes from the source of collector power supply 16 through divider 20, diode 18 and resistor 2, which is much lower impedance than divider 21. Due to the shunt effect of resistor 2, the voltage drop across divider 21 is small and the base – emitter junction of transistor 6 is closed by the reference voltage t / onop. For the second balanced comparison circuit, the bias current passes through divider 22, diode 19, and low-impedance resistor 3. The base-emitter transition of transistor 7 is also closed by the reference voltage t / onop. Since transistors 6, 7 are closed, there are no voltages on the output windings 24, 30, 34 of transformer 10, output thyristors and a neon light bulb are closed, and the voltage at the output of the f / o controller is zero. The appearance of the input signal t / Bx will cause a current at the output of amplifier 1, which creates a voltage drop across resistors 2, 3. Let the direction of the current be such that the voltage on resistor 2 tends to close diode 18 and the voltage on resistor 3 to open diode 19. If the voltage across the resistor 2 is equal to the reference t / onop, the dynamic resistance of diode 19 increases greatly and the bias current creates a voltage drop across the divider 21, which leads to the opening of the base-emitter transition of the transistor 6, while the voltage drop resistor 3 before Through diode 19 to divider 23, the transistor 7 will be even more locked. As a result of opening transistor 6, the positive feedback circuit transfer ratio: collector of transistor 6, diode 8, half 11, transformer 10, winding 40, divider 21, base-to-junction the emitter of transistor 6 becomes more critical. Due to the positive feedback in the comparator, the process of forming the working output pulse will occur. First, as a result of the regenerative | GO process, the transistor 6 abruptly saturates, the leading front of the working output pulse is formed. By flowing the base current at divider 21, the diode 18 is closed, and the comparison circuit is disconnected from the input signal. Then, the output pulse is formed, the duration of which is determined by the parameters of the transformer 10, the base current of the transistor 6, which is defined by the divider 21 and the current gain of transistor 6. At this time, due to the low saturation resistance of the transistor, the comparator has a high load capacity. Further, due to the increase of the magnetizing current of the transformer 10, the collector current will reach the limit value, a reverse regenerative process will occur, as a result of which the transistor will close abruptly and the back edge of the output pulse will be formed. During the generation of the working output pulse by the transistor 6, the magnitude of the voltage on the collector and the magnitude of the blocking voltage on the base-emitter transition of the transistor 7 increase even more. Although at the same time the voltage on the winding 12 is applied to the diode thyristor 14, which has an S-shaped volt-ampere characteristic, in the forward direction, the thyristor 14 remains in the closed state, since the switching voltage of the resistor is selected several times greater than the voltage of the collector power - SK. At the same time, the voltage on the winding 11 is applied to the thyristor 13 in the locking direction. Due to the action of the magnetizing current on the winding II, a reverse polarity voltage surge occurs, which leads to the switching of the thyristor 13. During the time determined by its switching time, the thyristor 13 will go to the open state. The formation of a reverse ejection is complete. On. the back-ejection time will open the base-emitter transition of transistor 7. However, this will not cause a positive feedback on the second input, since the voltage on the winding 11 will close diode 9 and the voltage on the collector of transistor 7 will drop to zero. Due to the active losses in the circuit formed by the winding 11 and the thyristor 13, the magnetizing current of the transformer 10 drops. In this case, the voltage on the winding 11 is determined by the residual switching voltage of the thyristor 13. The magnetizing current reaches the reverse switching value of the thyristor 13, and. thyristor closes. The further nature of the decay, the magnetising current, and therefore the magnitude of the return zone of the comparator is determined by the value of the resistor 15. When the normal process of magnetizing the current is terminated, the generation of the new operating output impulse will begin. At the stage of restoring the magnitude of the voltage on the collector and the blocking voltage at the junction, the base of the emitter of the transistor 7 decreases slightly, however, the transistor 7 remains a closed reference voltage. At the backstage stages, the thyristor 14 is closed by the reverse voltage on the winding 12. When the output current of the amplifier 1 is changed and if the voltage on the resistor 3 is equal or more, the comparator will work but the input diode 5 will increase. 19, the transistor 7 will open and the transmission coefficient of the positive feedback circuit: collector of transistor 7, diode 9, winding 12, transformer 10, winding 41, divider 23, base-emitter junction of transistor 7 will become more critical. A working output pulse of reverse polarity will be formed, after which thyristor 14 will switch. Otherwise, the processes when the comparator is triggered by inputs 4 and 5 are similar.

Instead of diode thyristors 13, 14, it is possible to use other semiconductor devices with an S-shaped current-voltage characteristic (triode thyristors, symmetrical thyristors, avalanche transistors, single junction transistors, etc.).

Thus, on the output windings of the comparator, depending on the sign of the input signal, a sequence of pulses appears. Usually for a feedback circuit with a neon lamp in order to obtain a wide range of settings for the regulator, a voltage of 100-200 in the output winding 34 is required. Therefore, the supply voltage of the comparator 2k is selected within 10-20 volts, based on a reasonable compromise between the complexity of the pulse transformer 10 and power supply 16. To turn on high-power output thyristors 28, 29, the duration of the working output pulses must be at least 5-10 microseconds. Consequently, the duration and volt-second area of the working output impulse is hundreds of times longer and the volt-second plane of the backflash, since the non-retry time of modern thyristors, made according to planar technology in an integrated design, is ten nanoseconds and less.

The residual switching voltage of the thyristors 13, 14 ne exceeds 0.5-1.0 V, therefore, the amplitude of the working output pulse is 10-20 times greater than the reverse voltage at the recovery stage.

Such a strong difference between the working output pulse and the back surge and voltage in the recovery stage makes it possible to isolate the working output pulses with the simplest means of selection in duration, namely using passive RC filters and amplitude detectors.

In the feedback circuit, the selector is made up of a resistor 35 n capacitor 36 and a neon lamp 37 in duration. Moreover, the capacitor 36 has a very small capacitance which can be formed by the capacitance of the assembly. The constant of the link 35, 36, which is small compared to the duration of the working OUTPUT of the pulse, will only lead to a certain tightening of its fronts; however, it is enough that the amplitude of the reverse emission does not exceed the ignition threshold of the neon lam. 37, which performs the phase-sensitive discharge - the magnitude of the working output pulses and, therefore, the charge of the feedback capacitor 39 by a positive polarity when the comparator is triggered by the input 4 and the voltage m of negative polarity when the comparator is triggered Inlet 5.

In the thyristor control circuit 28, the selector is formed by the length of 25, 26n and diode 27, which, when the comparator is triggered by the input 4, select the operating output pulses and turn on the thyristor 28. There is a voltage at the output of the regulator. In this case, at the stages of the back surge and recovery, the voltage on the capacitor 32 is less than the threshold voltage of the diode 33 and the thyristor 29 is closed.

When the co.parator is triggered by the input 5, the thyristor 29 is turned on. The duration of the thyristors 28, 29 is switched on is determined by the response threshold of the comparator return zone as a relay element of the regulator and the parameters and settings of the regulator feedback circuit. Turning off the transistors 28, 29 is performed every half-period of the supply voltage across the anode.

Thus, a relay element with a three-position relay characteristic, whose output signals are used simultaneously to control the neon lamp in the feedback circuit and the output of the thyristor and their regulator, is made on a single pulse tract of the transformer, which simplifies the device compared to with known.

To build a relay element, one transformer, one collector power supply, one reference voltage source and two transistors are used, which ensures that the characteristics of the device are identical across the phases of the input voltage. Although the difference in the current transfer coefficients of the transistors doesn’t lead to the nonidentity of the duration of the working pulses, the self-leveling property is inherent in the scheme, since the change in the duration of the working pulses is associated with a proportional change in the magnetizing current and with a reverse change in the recovery time, and therefore, with a constant pulse duration which is important for the feedback circuit.

The comparator trigger threshold, due to the relay characteristic, does not depend on the spread of the thyristors. There is no need for a large number of adjustments to the controller.

The output of the thyristors is triggered by a continuous sequence of pulses with a high frequency. Therefore, the turning-on angle of the thyristors does not exceed one degree, and the voltage losses on the load are reduced. The reliability of the device is increased in comparison with the known ones.

Subject invention

A relay controller for controlling a constant speed actuator, containing an amplifier and an actuator on thyristors in the forward channel and a CS link with a neon lamp in the feedback circuit, characterized in that, in order to simplify and improve reliability, the forward channel the regulator is supplied with a regenerative .m voltage comparator, made on two transistors and a pulse transformer with several windings and a load element in the form of a semiconductor device, with a symmetric S-shaped volt-ampere characteristic, and one of the transformer windings having a midpoint, through the diodes connected to the collectors of transistors, and the other coil via the selectors duration chains connected to a control thyristors and neon lamps.

Ш1з:

55

39

g

1Q

25 27