SU1651365A1 - Ac commutator - Google Patents

Abstract

The invention relates to a pulse technique and can be used in alternating voltage switching devices on active-inductive loads. The purpose of the invention is to increase reliability and speed. The alternating voltage switch contains transistor switches 1–4, current transformers 17–1, 17–2, each of which contains two primary and two secondary windings, threshold elements 13–16, and buses 27, 28 of the alternating voltage source; Each transistor switch 1-4 contains control and power transistors 20, 21, respectively. Introduction of current transformers 17-1, 17-2, threshold elements 13-16 and their corresponding inclusion allows to exclude the appearance of through currents, 1 sludge,

Description

The invention relates to a pulse technique and can be used in secondary power supply sources, for example, for switching an alternating voltage at an active-inductive load.

The purpose of the invention is to increase reliability and speed.

The drawing shows the basic electrical circuit of the proposed switch.

The switch contains four transistor switches 1 ... 4, four first resistors 5 ... 8, a control transformer 9, windings 10 and 11 of which form paraphase busbars, and winding 12 is an input, four threshold elements 13-16 and two transformers 17-1 and 17-2 currents with primary and secondary windings 18-1 ... 18-4 and 19-1 ... 19-4 respectively.

Each transistor switch contains a control and power transistors 20 and 21, the first and second diodes 22 and 23, the second resistor 24, the first terminal of which is connected to the first output winding 19-1 ... 19-4, emitter of transistor 21, anode diode, respectively 22 and connected to the first output of the key, the second output of the resistor 24 is connected to the anode of the diode 23, the base of the transistor 21 and the emitter, the transistor 20, the collector of which is connected to the second output of the corresponding winding 19-1 ... 19-4.

The cathode of the diode 22 and the second output of the corresponding winding 18-1 ... 18-4 are connected to the second output of the key, the first output of which is connected to the collector of the transistor 21.

The base of the transistor 20 of the corresponding key 1 ... 4 is connected via the corresponding resistor 5 ... 8 to the corresponding parsphase bus and to the first output of the corresponding threshold element 14, 13, 16 and 15, the second output of which is connected to the collector of the transistor 20 keys 2, 1, 4 and 3, respectively.

The first outputs of keys 1 and 3 are connected to the first outputs of keys 2 and 4 and to the second outputs of windings 10 and 11 of transformer 9, respectively, the winding 12 of which is connected to the first and second buses 25 and 26 of the source of equalizing voltage. The second outputs of the keys 1 and 4 are connected to the buses 27 and 28 of the variable voltage source

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respectively, the second outputs of the keys 2 and 3 are interconnected and connected via the bus 29 and the load to the common bus. The successively included keys 1-4 are combined into two keys of two-sided conductance with proportional-current control, forming the rack of an alternating input voltage switch. Transformers 17-1, 17-2 are made common for keys 1, 4, and 2, 3, respectively, and are two four-winding transformers operating in a two-stroke (symmetrical) mode at the frequency of the input source.

The threshold elements 13-16 may consist of two series-connected diodes.

The switch works as follows.

Tires 27 and 28 are supplied with a variable voltage of arbitrary shape from a source of alternating voltage. In the absence of a control voltage on buses 25 and 26, transistors 20 and 21 of all keys are closed, the voltage on

bus 29 is missing i

When the alternating voltage form 25 and 26 is applied, the square wave is controlled by keys 1–4, moreover, when the voltage between the buses 25 and 26 is positive, the voltage on the winding 10 (11) is unlocking (locking) for transistors 20 and 21 keys 1 and 2 (3 and 4), while the keys 3 and 4 are open, and the keys 1 and 2 are closed. Depending on the polarity of the voltage between the buses 27 and 28, one of the transistors 21 of the keys 1 and 3 turns out to be forward and the other in the inverse state. With a positive (negative) input voltage, bus 29 is connected to bus 27 via transistor 21 of key 1 (2), the corresponding winding 18-1 ... 18-4 of key 1 (2), diode 22 of key 2 (1). The direction of the current to the bus (from the bus) 29 is accepted positive (negative). Due to the magnetic coupling of the windings of the transformers 17-1 and 17-2, a positive (negative) current is applied to the collector 20 of the switch 1 (2) through the corresponding winding 18-1 ... 18-4 of the positive current from the corresponding winding 19- 1 ... 19-4, supporting the base current of the transistor 21 proportional to the load current, to the collector of the transistor 20

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The key 4 (3) is the negative voltage of the corresponding winding 19-1 ... 19-4, but the threshold element 16 (15) is closed, since the voltage on the winding 11 is also negative. After changing the polarity of the voltage between the buses 25 and 26, the transistor 21 of the switch 1 (2) will begin to dissipate, its base current flows through the circuit: the base of the transistor 21, dioce 23, resistor 5 (6), winding 10, emitter of the transistor 21. Polarity the voltages on the windings of the transformers remain the same. The threshold element 16 (15) opens and the negative voltage of the corresponding winding 19-1 ... 19-4 goes to the base of the transistor 20 of the switch 3 (4), prohibiting it to turn on. This is the protection against through currents.

After the transistor 21 of the key 1 (2) is absorbed, it closes, the voltage on the corresponding winding 19-1 ... 19-4 changes polarity, the threshold element 16 (15) closes and the voltage of the winding 11 opens the key 4 (3). If the input voltage is positive (negative), the bus 29 is connected to the bus 28 through the transistor 21 of the switch 3 (4) corresponding to the coil 18-1, .. 18-4, the diode 22 of the switch 4 (3), while the negative (positive) load current, the collector of the transistor 20 of the key 3 (4) is applied a positive voltage of the corresponding winding 19-1 ... 19-4, supporting a positive current connection, to the collector of the transistor 20 of the key 2 (1) - negative voltage the corresponding winding 19-1 ... 19-4, the threshold element 14 (13) is closed. When the voltage between the buses 25 and 26 becomes positive again, the threshold element 14 (13) opens for the dissolving time of the transistor 21 of the switch 3 (4) and keeps the switch 1 (2) in the open state. After unlocking key 3 (4), the device returns to its original state, then the processes are repeated.

Claims (1)

Invention Formula An alternating voltage switch containing four transistor switches connected in series between the buses of an alternating voltage source, whose common bus is through 13656 the load is connected to the combined pins of the second and third transistor switches, the control inputs of the first, second and third, fourth transistor switches are connected respectively to two pairs of control paraphase busbars, the second and fourth control paraphase buses are connected to the first outputs of the first, the second and third, fourth transistor keys, respectively, each transistor key contains a control and a power transistor, the base of the first of the 15 of which are connected through the first resistor to the first control input of the transistor switch, the base of the power transistor is connected to the first terminal of the second resistor, the emitter is connected to 20 by the first output of the transistor switch, which is connected back to the second diode through the second output of the transistor switch, and a second diode, characterized in that 25 in order to increase reliability and speed, two four-winding current transformers and four threshold elements are introduced, the first and second primary windings of the first current transformer are connected between the collectors of power transistors and the second outputs of the first and fourth transistors, the first and second secondary windings are connected between the second terminals second resistors, emitters of power transistors and collectors of control transistors of the first and fourth transistor switches, respectively, and autoApp the primary windings of the second trans-Lormator current are connected between the collectors of the power transistors and the second outputs of the second and third transistor switches, the secondary windings ds are connected between the second pins second resistors, emitters of power transistors and collectors of control transistors, the second and third transistor switches, respectively, The CQ bases of the power transistors of all transistor switches are connected to the emitters of the control transistor and through the back-connected second diodes to the bases of the control transistors, collectors of the control transistors 35 55 the first and fourth transistor switches are connected via the corresponding threshold elements with the bases of the control transistors of the second and three I of the transistor keys, and the collection of elements with control bases control transistor tori of the second and fourth transistor and the third transistor switches soi-transistor keys, respectively, dineny through the corresponding thresholds,