SU1653150A1 - Transistor-magnetic switch - Google Patents

Description

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{21) 4418968/21 (22) 03.05.88 (46) 30.05.910 Bul V 20

(71) Moscow Energy Institute

(72) A.P.Valkovoi, S. 1 Buzykin, A.P. Gabov, B.A. Glebov, V.Yu.Golikov and N.B. Roznin

(53) 621.382 (088.8)

(56) Klaus Rischmuller. Darlington - Kadule mit designer Shaltverlusten. - Electronic, 1983, No. 18, s.108-112. Zavlov M.1I, Optimization of parameters of current transformers in the control circuits of transistor power amplifiers. Theses of reports of the All-Union Scientific and Technical Conference: Problems of converting equipment. Kiev; Part 3, 1979, p. 163, fig.2.

(54) MAGNETIC-TRANSISTOR KEY (57) The invention relates to a pulsed technique and can be used in control systems. The purpose of the invention is to increase reliability and speed. The magnet-transistor switch contains power transistors 1-4, connected to buses 5, 6 of a constant voltage source according to a bridge circuit, in the diagonal of which there is a load 7, control current transformers 8-11 with primary windings 12-15 and secondary windings 16-19, additional current transformer 20 with primary winding sections 21, 22, secondary winding 23 and energy output circuit 24, current-measuring resistor 25, diode 26, capacitor 27, bias current source 28, auxiliary switches 29,

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30, the control inputs of which are connected to the outputs 32, 33 of the control device 31 having a measuring input circuit 34, a threshold element 35, a trigger 36, logic elements OR 37, AND 38, 39 and two control

The invention relates to a pulse technique and can be used in control systems and control, in the electric drive, in automation devices 0

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

Figure 1 shows an embodiment of the device; 2 shows an embodiment of control current transformers in the form of a single magnetic

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The magnetically-transistor switch contains power transistors 1-4 connected to the buses 5, 6 of the source with a constant voltage on the bridge circuit, in the diagonal of which the load 7 is connected, the control transformers 8-11 of the current with the primary windings 12-15 and the secondary windings 16-19, additional current transformer 20 with primary winding sections 21, 22, secondary winding 23 and energy output circuit 24, current measuring resistor 25, diode 26, capacitor 27, bias current source 28, auxiliary switches 29, 30, device 31 controls with outputs 32, 33 and c will measure Flax input circuit 34.

The control unit contains a threshold element 35, a trigger 36, a logical element OR 37, two logical elements AND 38, 39 and two control inputs 40, 41.

The load terminals 7 through the junctions collector - base power transistors 1, 2 are connected to bus 5 and connected to another bus 6 through serially connecting section 21 of additional current transformer 20 n junction collector - base of force transistor 3 and through connected in series 22 primary section of additional winding current transformer 20 and the collector junction - base of the power transistor 4. Secondary

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Inputs 40, 41 o. The introduction of an additional current transformer 20, a resistor 25, a diode 26, a capacitor 27, and a source 28 provide comprehensive protection for the device and increase its reliability. 2 Il.

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the winding 23 of the additional current transformer 20, the current-measuring resistor 25 and the diode 26 form a series circuit, to the terminals of which

 Connected: mixing current source 28, capacitor 27; a circuit of connected in series and according to the primary windings 12, 14 of the control transformers 8, 11 of the current and the auxiliary switch 29; a circuit of connected in series and according to the primary windings 13, 15 of the control transformers 9, 10 of the current and the auxiliary switch 30. The secondary windings 16 and 19 of the control transformers 8 and 11 of the current are connected each between the base and emitter of the power transistors 1 and 4, respectively. Secondary windings 17, 18 control current transformers 9, 10 are connected each between the base and the emitter of the power transistors 2 and 3, respectively.

The invention does not change if each of the load terminals 7 is connected to bus 6 via a junction collector — the base of the power transistor 3 and 4, respectively, and with bus 5 — through a chain of connected sections 21, 22 of the primary winding of the additional current transformer 20 and the junction the collector is the base of the power transistor 1 and 2, respectively. It is also possible to interchange these elements in the circuit of the series-connected primary winding sections and the collector junction — the base of the power transistor. In the latter case, the primary winding sections may be connected in parallel or the winding may contain a single section.

The input circuits of the auxiliary switches 29, 30 are connected to the outputs of the control device 31, having two

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the control inputs 40, 41, and the current-measuring resistor 25 is connected to the input circuit of the threshold element 35, which is also the measuring circuit of the control device 31. The output of the threshold element 35 is connected to the R-input of the trigger 36, and the S-input of this trigger through the element OR 37 is connected to the first inputs of logic elements: And 38 and 39, in which the second inputs are connected to the output of the trigger 36 "The first inputs of logic elements And 38 and 39 are simultaneously the first and second control inputs 40 and 41 of the control device 31.

The principle of operation of the magnet-transistor switch is as follows.

Upon receipt of the unlocking signal, for example, to the input 40, the trigger 36 is set to a state with a high level at the output, and the element 38 transmits the unlocking signal to the control input of the auxiliary switch 29, which leads to its transition to the high conductivity state. The source current 28 and the discharge current of the capacitor 27, the bias current charged by the source 28, begin to flow through the primary windings 12, 14 and the auxiliary switch 29. Transforming the current of the primary windings 12, 14 into the secondary windings 16, 19 causes unlocking (initial) power transistors 1 and 40 At the same time, the current from the bus 5 starts to flow through the circuit of the collector-emitter connected in series of the power transistor 1, winding 16, load 7, section 22 of the primary winding of additional transformer 20, collector-emitter junction 4 yl transistor winding 19. From section 22 of the primary winding of the transformer 20 additional current is transformed to the secondary winding 23 of this transformer. The winding current 23, proportional to the load current flowing through section 22, is closed through diode 26, primary windings 12, 14 of control transformers 8 and 11, auxiliary switch 29 and current measuring resistor 25. This current, transforming into secondary windings 16 and 19, ensures the flow through the emitter circuits of power transistors of a current greater than the load current 7 flowing through the collector circuits

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power transistors 1 and 4. As a result, the power transistors go into saturation mode, with the emitting emitter current and the current of the collector junction being proportional to the link, and the proportionality factor by selecting the transformation ratios of the additional and control transformers is set to a larger unit.

The removal of the unlocking signal from the input 40 causes the appearance at the output of the element 38 of the logical O, i.e. in the input circuit of the auxiliary key 29, the unlocking signal disappears, the key goes into a low conductivity state, and the circuit of the windings 12, 14 is broken. At the same time, in the emitter circuit of power transistors 1 and 4, the flow of the unlocking current also stops, and the secondary windings 16 and 19 become significant inductive resistances j and also increases the speed, since their control mode corresponds to the most high-speed control scheme with a common base.

After the auxiliary switch 29 opens, the current through the load 7 continues to flow for the time required to dissolve the charges in the bases of the power transistors 1 and 4 and lock their collector transitions. At this stage, the current of the winding 23 is closed through the capacitor 27. or the same accumulated charge in the capacitor 27 is used to force the process of turning on the power transistors belonging to the opposite shoulders of the bridge.

After locking the power transistors, the energy stored in the transformers is dissipated in the power output circuit or returned to the power source using, for example, circuit 24

In the embodiment of control current transformers of the opposite arms of the bridge as a single magnetic unit, the common primary winding of each pair of control current transformers is magnetically connected to two cores.

mi, on which there are one secondary winding, and therefore the currents of these windings are proportional to the current of the common primary winding, which closes through the corresponding auxiliary key.

If for any reason (overload, short circuit in the load, exit from

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an increase in the current in the winding circuit 23 will occur above a predetermined threshold level, at the output of the threshold element 35 a signal is received, by which the trigger 36 goes to state O, and through the logic elements 38, 39 the unlocking signal to the inputs of the auxiliary switches 29, 30. Thus, comprehensive protection is provided.

functional reliability is increased throughout the device.

Claims (2)

1. A magneto-transistor switch containing four power transistors, the output circuit of each of which is included in the corresponding shoulder of the bridge, in one diagonal of which the load is included, and the other diagonal is connected to the busbars of the constant voltage source, four control transformers, two auxiliary key and control device, characterized in that, in order to increase reliability and speed, an additional current transformer, current-measuring resistor, diode, capacitor and bias current source, m one power bus connected to the first and second load terminals through the collector-base junction, respectively, of the first and second power transistors, another bus Q 0 5 Q five through the circuit from the serial section of the primary winding of an additional current transformer and collector-base junction of the third and fourth power transistors, respectively, the secondary winding of the additional current transformer, current measuring resistor and diode form a series circuit, to the terminals of which are connected in parallel capacitor serially connected first auxiliary switch and primary windings of the first pair of control current transformers, which secondary windings are connected between the emitter and the base, respectively, of the first and fourth power transistors, a chain of series-connected second auxiliary switch and primary windings of the second pair of control current transformers, in which the secondary windings are connected between the emitter and the base of the second and third power transistors, respectively the inputs of the auxiliary switches are connected to the corresponding outputs of the control device, the measuring input circuit of which is connected to the tokoism itelnomu resistor. 2. The key pop. 1, characterized in that each pair of control current transformers is made in the form of a single magnetic unit containing two cores, with the series-connected primary windings of each pair of control current transformers being magnetically connected to two corresponding cores, each of which the secondary winding of the corresponding transformer is placed d i sixteen and J FIG. 2