SU714367A1 - Three-position relay - Google Patents

Description

i

The invention relates to the field of automation and is intended in combination with various resistance sensors (thermistors, photoresistors, hygristors, etc.), current, voltage, etc. for three-position control of temperature, pressure, current, voltage, etc. quantities

A three-position relay is known, which contains a three-position sensitive device, a blocking generator, an isolation transformer, and a half-wave rectifier on thyristors. A disadvantage of the known device is the absence of a dead zone and a differential between switching actuators 1.

It is also known a contactless relay with a threshold device on a single junction transistor with an RC-circuit in the emitter circuit of the transistor. A disadvantage of the known device is that it does not provide a three-position response characteristic of the actuators 2.

The aim of the invention is to provide the possibility of three-position adjustment of the parameters of the controlled object with high reliability of operation.

To achieve this goal, a three-position relay contains a threshold element at the first unijunction transistor, the first base of which is connected to the control electrode of the first thyristor, the cathode of which is connected to a common terminal to which one pin of the resistor is connected, the other pin of which is connected to the first base of the first uni junction transistor, the emitter of which is connected through a capacitor to the common bus and through a resistor to the connection point of the first terminals of the resistance sensor and the variable resistor, and The second output of the resistance sensor is connected to the common bus, and the second output of the over-resistor to the movable contact of the potentiometer, one fixed output of which is connected to the common bus through a variable resistor, and the second fixed output to the positive terminal of the DC power supply, additionally introduced threshold elements transistors, capacitors, resistors, diodes, potentiometers, triacs, with the fifor base of the first single junction transistor through a cogenerator connected to its emitter and 46; a resistor with a movable rotary potentiometer, the first fixed output of which is connected to the positive supply source bus; direct current second stationary in .-. water through a constant resistor and a variable resistor connected to the bus, her bus and directly to the anode of the diode, the cathode of which through a resistor connected to the junction of the anode of the first thyristor with the first terminals of the resistor, the second output of which connected to the control of the first triac electrode of the triac, and the first output of the capacitor, the thief whose output is connected to the first bus of the AC source and to the first current output of the first triac, KOTOpiie is connected via a resistor to the positive w. DC power supply, to which one capacitor plate is connected, the second plate of which is connected to the second single-junction transistor. The first base of which is connected to the control electrode of the second thyristor, the cathode of which is connected to the common bus, to which one output of the resistor is connected, the second output which is connected to the first base of the second one-junction transistor, the emitter of which through a capacitor is connected to the second base of its single-junction transistor, which through a resistor The first fixed output is connected to the positive pin of the DC source, the second fixed output through a resistor is connected to a common bus and indirectly to the anode of a diode, the cathode of which is connected via a parallel connection to the anode of the second thyristor. resistor and capacitor under; l is very close to the first bus of the AC source, to which the first one is connected | The second BC11VOD of the second triac, the control electrode of which through a resistor is connected to the connection point of the first capacitor plate, the second facing of which is connected to the first current output of the second triac and the anode of the third thyristor, the cathode of which is connected to the common busbar, equalizer electrode to the first base the third unijunction transistor directly and through a resistor to the common 1iin, to which one output of the resistor is connected, the second output of which is connected via a resistor to the positive bus of the constant source and directly to the second base of the third single junction transistor, whose emitter is connected via a capacitor to the common bus, via a resistor to the positive power supply line of the direct current and directly to the anode of the diode, the cathode of which is connected to the emitter of the second single junction transistor and to the point the connection of the anode of the diode and the first output of the resistor, and the cathode diode is connected to the emitter of the first single junction transistor, and the second output of the resistor to the connection point of the ground sensor and the variable resis ora, second bus AC power source via respective actuators connected to the second current terminals of the first and second triacs. FIG. 1 is a schematic diagram of the device. B three-position relay containing a threshold element on the unijunction transistor 1, the first base of which is connected to the control electrode of the thyristor 2, the cathode of which is connected to the common bus 3, to which one output of the resistor 4 is connected, the other output of which is connected to the first base of the single junction transistor 1, the emitter of which is connected through a capacitor 5 to the common bus 3 and through a resistor 6 to the connection point of the first terminals of the resistance sensor 7 and the variable resistor 8, and the second terminal of the resistance sensor 7 is connected to The common bus 3 and the second output of the variable resistor 8 are connected to the first contact of the potentiometer 9, one fixed output of which through the variable resistor 10 is connected to the common bus 3, and the second fixed output to the plus bus 1 of the DC power supply is additionally introduced threshold elements on unijunction transistors, capacitors, resistors, diodes, potentiometers, and triacs, the second base of the unijunction transistor 1 connected to its emitter through a capacitor 12 and to a movable potential contact through a resistor 13 the meter 14, the first fixed output of which is connected to the p.tusus busbar 11 of the DC power supply, the second fixed output through the fixed resistor 15 and the variable resistor 16 is connected to the common bus 3 and directly to the anode of the diode 17, the cathode of which resistor 18 is connected to the connection point of the anode t} of the fistor 2 with the first output of the resistor 19, the second output of which is connected to the control electrode of the triac 20, and the first output of the capacitor 21, the second output of which is connected to the first bus 22 of the extinguished current source and to the first The current output of the CI diode 20, which through a resistor 23 is connected to the positive bus 11 of the DC power source, to which one plate of the capacitor 24 is connected, the second plate of which is connected to the emitter of the single junction transistor 25, the first base of which is connected to the control electrode of the thyristor 26 whose cathode is connected to the common bus 3 to which one is connected

the output of the resistor 27, the second output of which is connected to the first base of the unijunction transistor 25, the emitter of which through capacitor 28 is connected to the second base of its unijunction transistor 25, which through the resistor 29 is connected to the movable contact of the potentiometer 30, the first fixed output of which is connected to the positive bus AND source direct current, the second fixed output through the resistor 31 is connected to the common bus and directly to the anode of the diode 32, the cathode of which through the resistor 33 is connected to the anode of the thyristor 26, which is black Without parallel connection of the resistor 34 and the capacitor 35 is connected to the first bus 22 of the AC source, to which the first current lead of the triac 36 is connected, the control electrode through the resistor 37 is connected to the connection point of the first capacitor plate 38, the second plate of which is connected to the first the current output of the triac 36, and the anode of the thyristor 39, the cathode of which is connected to the common bus 3, the control electrode to the first base of the single junction transistor

40 directly and through a resistor

41- to the common bus 3, to which one pin of the resistor 42 is connected, the second pin of which is connected via the resistor 43 to the positive bus 11 of the DC source and directly to the second base of the single junction transistor 40, the emitter of which is connected via a capacitor 44 to the common bus 3 through a resistor 45 to the plus bus 1 of the DC power supply and directly to the anode of the diode 46, the cathode of which is connected to the emitter of the single junction transistor 25 and to the connection point of the anode of the diode 47 and the first output of the resistor 48, and the cathode 47 p Connected to the emitter of the unijunction transistor 1, and the second output of the resistor 48 to the connection point of the resistance sensor 7 and the variable resistor 8, the second section 49 of the alternating current source through the respective executive bodies 50, 51 is connected to the second current leads of the triacs 20, 36 and directly - to one output of the primary winding of the transformer 52 of the DC power source, the second terminal of which is connected to the first bus 22 of the AC source, the secondary winding of the transformer of the power source is constant current inputs is connected to the bridge rectifying unit 53, the positive terminal of which is connected to the positive plate of the capacitor 54 of the filter and to the positive bus power supply DC and the - terminal to the negative plate of filter capacitor 54 and to a common Ishna 3.

Fig. 2 shows time diagrams at characteristic points of a three-position relay, at a temperature above the norm (Fig. 2a), equal to the norm (Fig. 26) and less than the norm (Fig. 2c),

where Ug is the voltage plots on the capacitor 44

and 4o threshold of the threshold element on the unijunction transistor 40

Us 5.4., - voltage plots on capacitor 24

E source - power supply voltage 0dc

Uc5, - voltage diagram on capacitor 5

UTI - threshold triggering of the threshold element on the unijunction transistor 1

five

UTJS threshold of the threshold element on the unijunction transistor 25

and / .- voltage on the upper output of the resistance sensor 7 relative to the common bus 3

4.0 - the oscillation period of the generator is

transistor 40 T i.s ...- the oscillation period of the generator on

transistor 25

T, is the oscillation period of the generator on

5 transistor 1

The device works as follows.

When the supply voltage is applied, the transistor 25 is opened, since its emitter is connected to the positive power source through a capacitor 24, and the latter transmits through itself, the transistor 25 and the control electrode-cathode gap of the thyristor 26 a current pulse. In this case, the capacitor 24 is closed up to the voltage of the power source, and the thyristor 26 is opened and held in the open position by the direct current flowing through its anode circuit. When, for example, temperature is controlled

0 in the installation area of the sensor 7, the resistance is above the norm, its resistance is small and the voltage drop across it will be lower than the voltage of the unlocking transistors 1 and 25. And since the HC circuit 45, 44 is connected directly to the power supply, the capacitor 44 is charged to voltage in which the emitter-base transition of the transistor 40 is shifted in the forward direction. At these times, the transistor 40 will turn on, and the capacitor 44 is discharged to the resistor 41,

0 causes unlocking of the thyristor 39. At the same time, the thyristor 26 is locked due to the switching capacitors 35 and 38 and the common resistor 23. Through the gap the cathode control electrode of the triac 36, the resistor 37 and the anode circuit of the thyristor 39 are flowing current

the action of which the triac 36 is unlocked. An actuator 51, for example, a relay, an electromagnet, a two-phase electric motor is turned on, reducing, for example, the flow of coolant to the control object. With the help of resistors 42 and 43, the pickup threshold of the transistor 40 is set obviously below the pickup threshold of transistors 1 and 25. Therefore, although capacitor 44 is connected through dividing diodes 46 and 47 to the emitters of transistors 25 and 1, in this case only the transistor 40 will be unlocked periodically.

When the temperature of the control object decreases to its nominal value, the resistance of the resistance sensor 7 increases and the voltage across it increases to a value greater than the voltage of the unlocking of the transistor 25, but lower than the voltage of the unlocking of the three-position relay. Therefore, capacitor 24 begins to periodically charge through the emitter-base transition of transistor 25 to resistor 27, causing thyristor 26 to unlock. Thyristor 26, when unlocked, causes capacitor 36, 38 and resistor 23 to close the thyristor 39. Triac 36 closes and the actuator 51 is turned off. Through the separation diode 46, the capacitor 44 is discharged to the emitter-base of the transistor 25, blocking the transistor 40 from periodic operation. As soon as the thyristor 26 is unlocked, by shunting the resistor 31 through the separation diode 32 by the resistor 33, the voltage of the second base of the transistor decreases. This ensures the creation of a differential between the switchings of the executive body 51.

If the temperature drops below normal, the voltage drop across the resistance sensor 7 exceeds the response threshold of transistor 1. Consequently, capacitor 5 will periodically discharge through the emitter base of transistor 1 to resistor 4. In this case, the thyristor 2 and triac 20 will turn on and the executive body 50, carried out an increase in the flow of coolant. By means of capacitors 21 and 35 and resistor 23, the thyristor 26 is locked. Unlocking, transistor 1 will periodically discharge capacitor 44 through discharge diodes 46 and 47, and charge capacitor 24 discharging to resistors 48 and 8, blocking unlocking transistors 25 and 40. By shunting resistor 15 through resistor 18 through diode 17 and the thyristor 2 decreases the threshold of unlocking of the transistor 1. This creates a differential}) duration between the threshold of actuation and disconnection of the actuator 50. In the future, the operation of the regulator is repeated.

The RC time constant 48, 24 is chosen higher than the RC time constant 5, 6 and below in m RC in circuit 46, 44. The tripping voltage of the three-point relay is controlled by the sweat (Chip light 14, 30. Setpoint the relay is triggered by a potentiometer 9. The total insensitivity between the actuators 50 and 51 actuators is changed when Pomon 1 and the variable resistor 16. Capacitors 12 and 28 provide an effective value for the relay circuit.

(The above is illustrated with diagrams for example, at characteristic points of a three-position relay.

At temperatures in the sensor zone more

the norm (Fig. 1a) relaxes only the generator on the transistor 40. The voltage on the capacitor 24 decreases by the amount of voltage on the sensor Uy. On capacitor 5, the voltage is UT.

If the sensor temperature is equal to the set-point temperature, the generator at the transistor 25 relaxes. In this case, the voltage across the capacitor 24 (Uci4) changes by approximately the value of the unlocking threshold of transistor 25 (Utg). On capacitor 44, the voltage Ue ++ does not reach the unlocking threshold of transistor 40 (it4o) - The voltage on the capacitor 5 (LIcs) is less than the threshold of the transistor (Ueri).

When the temperature is lower than the preset time: 1: the generator is connected to the transistor 1. In the case of a capacitor 5, it is charged to the threshold of the transistor 1 and charged to the residual voltage of the transistor. Capacitor 24 does not have time to discharge by LTJS value due to charging through diode 47 before voltage supply E is not. The capacitor 44, discharging through diode E 1 46 and 47 to tra 1 sistor 1, does not have time to charge before the voltage is triggered; 1 of the transistor 40 (Uris). As can be seen from the diagrams, the time Tg5 Ti for which the time constants are chosen t t, if f s.9, ", useses9- UT4o threshold

 IJTiS UTI.

0 Since the unijunction transistors used in the relay circuit as poroFUjix elements are characterized by a high stability of the response threshold when the voltage fluctuates within the maximum voltage range.

j power and ambient temperature, the proposed relay has a high accuracy of operation. The three-position relay circuit is characterized by simplicity and non-contact, which makes it highly reliable in operation. The device is characterized by high

0 sensitivity, its input resistance can reach hundreds of kOhms, and executive mechanisms of considerable power can be connected to its output. A suggested relay may be used.

Claims (2)

J not only in combination with temperature sensors, but can also be used with other sensors, such as photoresistors, hygristors, pressure sensors, and current. voltage, etc. In this case, the proposed device provides a three-position regulation of light, humidity, pressure, current and other quantities. The invention is a three-position relay containing a threshold element at the first single junction transistor, the first base of which is connected to the control electrode of the first thyristor, the cathode of which is connected to a common bus to which one output of the resistor is connected, the other output of which is connected to the first base of the first single junction transistor emitter which is connected through a capacitor to a common bus and through a resistor to the point of connection of the first terminals of the resistance sensor and the variable resistor, the second terminal of the sensor It is connected to the common busbar, and the second output of the variable resistor to the movable contact of the potentiometer, one fixed output of which is connected to the common busbar through the variable resistor, and the second fixed output to the positive lead of the DC power source, in order to three-position adjustment of the parameters of the controlled object with high reliability of operation, additionally introduced threshold elements on the same junction transistors, capacitors, resist oors, diodes, potentiometers, triacs, the second base of the first unijunction transistor is connected via capacitor to its emitter and through a resistor with a moving potentiometer contact, the first fixed output of which is connected to the plus terminal of the DC power supply, the second fixed output through a fixed resistor and the variable resistor is connected to the common bus and directly to the anode of the diode, the cathode of which through the resistor is connected to the connection point of the anode of the first thyristor with the first output of the resistor, The first pin of which is connected to the control electrode of the first triac, and with the first pin of the capacitor, the second pin of which is connected to the first AC power supply terminal and to the first current output of the first triac, which is connected via a resistor to the positive DC power supply source to which One capacitor plate is connected, the second plate of which is connected to the emitter of the second unijunction 67 GO transistor, the first base of which is connected to the control electrode of the second thyristor, the cathode of which It is connected to a common bus to which one pin of the resistor is connected, the second Kotoporo pin is connected to the first base of the second All-transition transistor, the emitter of which is connected via a capacitor to the second base of its single-junction transistor through the resistor connected to the movable contact of the potentiometer, the first fixed output of which is connected to the positive voltage source of a direct current source, the second fixed output through a resistor is connected to a common busbar and directly to the anode of a diode, the cathode of which through a resistor p is connected to the anode of the second thyristor, which is connected via a parallel connection of a resistor and a capacitor to the first shim of the ac source, to which the first current output of the second triac is connected, the control electrode of which through a resistor is connected to the junction point of the first capacitor plate, the second facing of which is connected to the first current output of the second triac, and the anode of the third thyristor, the cathode of which is connected to a common busbar, the control electrode - to the first base of the third single junction transition torus, directly and through a resistor - to a common bus to which one output of the resistor is connected, the second output of which is connected via a resistor to the positive DC-power bus and directly to the second base of the third single junction transistor, whose emitter is connected to the common bus through a capacitor, through a resistor to the positive terminal of the DC power source and directly to the anode of the diode, the cathode of which is connected to the emitter of the second single junction transistor and to the junction point of the diode anode and the first water is a resistor, the cathode of the diode is connected to the emitter of the first single junction transistor, and the second terminal of the resistor is connected to the junction of the resistance sensor and the variable resistor, the second bus of the alternating current source is connected to the second current leads of the first and second triacs. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 455330, cl. G 05 D 23/19, 09/07/78. 2. Thyristors. Technical reference. Translated from English, ed. Labuntsova, V.A., et al., 1971, p. 336, fig. 13-12. -; "g, o ,,., - uch - lh Hgcg