The circuit breaker dc (options)

 

(57) Abstract:

Multi-stage step-down chopper circuit for arc welding by providing a current flow between the electrode and the workpiece, while the circuit breaker includes an input constant current source, the first switching stage with the first switching device and the first inductor and the first cascade selectively connects the input constant current source between the electrode and the workpiece managed work cycle and switching speed, and a second switching stage, with the second switching device and the second inductor, and the second cascade is also selectively connects the specified input constant current source between the electrode and the workpiece with the above-mentioned controllable duty cycle and switching speed, in this regard, improvement breaker is that it contains the first and second chokes are wound on one core, and that circuit is provided feedback correction minimum current. The technical result is increased reliability. 2 C. and 22 C.p. f-crystals, 9 Il.

The present invention relates to a step-down chopper DC for use by the constant current, having a scheme to control the effective inductance between the step-down chopper and weld the workpiece.

Most welding power sources welding arc DC are single-stage or two-stage inverter to convert power source DC in controlled welding constant current by using a pulse-width modulator to generate a series of current pulses that have managed workflows, to limit the parameters of the welding operation. For many years it is known the use of breaker DC with a switching device controlled pulse-width modulator for supplying discrete current pulses from the source of DC power to the welding station. Breakers direct current used in welding are described in many patents. One of these many patents is patent N 5637246 issued by Ikegami (Ikegami), mentioned here for reference. This patent shows a design of a step-down chopper circuit used to control the power source of the welding arc with a drive from the engine, in which the toggle actuator is controlled by a comparator implementation is knitted with step-down chopper. Shows the General design and layout of control used in circuit breakers direct current, is used as the power source of the welding arc. Although the circuit breaker in this known patent is driven by a motor powered by the generator, the input constant current source for a step-down chopper is often rectifier, controlled single-phase or three-phase power source. The present invention, in particular, is intended for units with motor-driven, similar to that described in the patent N 5637246 issued Ikegami; however, it is also applicable to downward breaker, which uses the input rectified AC characterizing the input DC step-down chopper.

When creating a step-down chopper is often necessary to provide two or more power modules connected in parallel, and each of these modules provides a given amount of current, for example to 200 amps. In the past, each of powerful modules were connected in parallel and needed its own reactor to generate the required output inductance to control the flow of arc current and the modulation of the input pulse is mnogo module in the multi-stage breaker DC there were some difficulties. Since the output chokes different stages were parallel, the effective inductance of a step-down chopper was significantly reduced. As a result, there occurred a rapid increase in short circuit current, the rate of growth which could exceed 300 amps/sec. This rapid growth in the output current step-down chopper circuit creating a very rigid, sharply tapering arc and caused a significant splash. Thus, the use of two or more parallel powerful modules in the circuit breaker DC type, which is the focus of the present invention, is not suited for a smooth and controlled arc welding.

As another predposylki ideas mark that known circuit breakers direct current used for welding, had output choke or coil of variable inductance to control the growth rate of the short circuit current. With the introduction of larger inductance in the output circuit breaker growth rate was less. This lower growth rate leads to a softer, smoother arc with less spatter. A higher growth rate, which is called the reduced effective inductive reactive is onecause arc with a large splash. If forced reduction of the inductance to a greater value, the arc current may be sufficient to maintain the arc, which can lead to unstable arc during the welding operation. The problems associated with the design of inductors, low inductance, especially annoying at extremely low speed wire feeder. To solve the problems associated with high or low values of inductance in panyhose the breaker, the welding industry has borrowed mainly inverters, so that scheme alert can detect approaching a short circuit and start a scheme smooth output to set the current mode to control the rate of growth of current electronic means without significant dependence on the values of the inductance of the output choke. Use the inverter with current pulses controlled by electronic means, to control the welding operation has led to some difficulty consists in the fact that the system was unable to determine the exact time of a short circuit, especially when using long cables to the welding operation.

Disadvantages associated with parallel output chokes in the Board by tilting the characteristics of increasing current and decreasing the output current of downconverters still remain problems that plague step-down chopper and which cause uncertainty when coming down-Converter for welding. Lowering the converters often require two or more parallel powerful modules or switching stages to obtain the required load capacity. This requirement leads to the problems associated with parallel operation of inductors, the switching devices. In addition, lowering the breakers have no method of electronic control waveform signal in the welding cycle, so that problems associated with attempts to regulate the output inductor or inductors to control the rise and fall of the welding current, is not solved. All these problems have contributed to the preference of the inverters are less expensive, more robust and easy to maintain lowering the breakers.

The present invention relates to improvements in panyhose the breaker DC, used for arc welding, through which solved some of the problems associated with the use of one or more inductors or chokes, in particular samples is lennyg powerful modules. In accordance with one feature of the present invention parallel powerful modules used in the circuit breaker DC to increase the load capacity, current, when they are used for welding, modified so that the output inductor or inductors connected magnetic communication with one steel core with high magnetic permeability. Transformer connection of two or more chokes or inductors causes the inductive reactance in a separate power modules remains high, without reduction, usually associated with parallel installation of chokes or inductors. As an example, note that if the throttles of each of the parallel of powerful modules had inductive reactance 150 mH and were connected in parallel, the effective output inductance reduction circuit breaker in the case of two parallel powerful modules would be approximately 75 mH. Through the use of the present invention, the effective inductance in the two output stages of a step-down chopper is equal to 150 mH. This effectively doubles the inductance of the system and when podergivani circuit 150 amps/msec. As described above, the same system had an increase in current of about 300 amps/msec when the throttles were connected in parallel, but were not associated magnetic connection.

In accordance with this feature of the present invention, it is proposed improvements in multistage panyhose the breaker for arc welding, which causes the flow of current between the electrode and the workpiece. The circuit breaker includes an input constant current source, the first switching stage with the first switching device, the first flywheel diode and the first inductor and the first cascade selectively connects the input constant current source to the electrode and the workpiece at a controlled speed, the second switching stage, with the second switching device, the second flywheel diode and a second inductor, and the second cascade selectively connects the input constant current source to the electrode and the workpiece with the managed switching speed, and pulse-width modulator to control the switching speed in accordance with the control signal. Improvement corresponding to the invention, consists in the idea of providing magnetoresitive core and means for transformat the K. In accordance with the invention, a constant current source for step-down chopper circuit may be engine driven generator, such as described in U.S. patent N 5637246 issued Ikegami, or the power source of rectified alternating current. In accordance with the invention, it is possible to use multiple switching stages. In practice, panyhose the breaker using two parallel switching of the cascade. The switching devices are preferably bipolar transistors with insulated gate (IGBT), but can be and other fast-acting powerful switches, such as field-effect transistors (FETS).

Are you using the above multi-stage step-down chopper, or single-stage step-down chopper, the second feature of the present invention provides a method to control the effective inductance of the arc. This is done by control closed loop minimum arc current. In accordance with this feature of the invention, the error amplifier is used to integrate the arc voltage during the measurement or control of the arc current. When the arc current attempts to fall below a pre-selected minimum value is raised by the scheme, the control amplifier errors. This scheme supports at least the minimum current to the pre-selected level. By regulating the minimum current is controlled by the effective inductance of the arc without actually changing the size of the throttle or choke on the output of the reduction circuit breaker. By increasing the minimum arc current arc during the welding operation becomes softer with less spatter. As a consequence, the reduction of the minimum arc current causes an additional spray and creates a more penetrating arc. When using the present invention, the correction pattern to maintain at least the minimum current at the output of the reduction circuit breaker ensures that the arc during the welding operation never reaches a low voltage, for example zero, what is done if the arc unstable. Through the use of this feature of the invention, the arc remains stable even at very low speed wire feeder. In practice, the welding operation using this feature of the invention was carried out using the electrode wire L 50, supplied by Lincoln electric company" and is), and arc unexpectedly remained stable. This stabilizing feature of the present invention does not depend on the length of the electrode cable, which until now has been difficult, especially at low welding speeds.

The above feature of the present invention provides a pre-selected set minimum current for the welding operation. This feature is applicable, generally speaking, when the welding operation is controlled by a feedback circuit on the closed-circuit regulating the arc voltage to achieve a pre-selected set voltage. However, you can also apply the correction pattern minimum current when the circuit feedback in a closed loop regulates the output signal of the step-down chopper circuit to maintain the pre-selected welding current or pre-selected relationship of voltage and current, as in the case of welding. In accordance with another feature of the invention, the minimum current in the present invention may be a function of the average actual arc current. Through the use of this aspect of the invention, the minimum current set in the correction pattern, automatically adjusts the softness of the arc with the change speed wire feeding or wire diameter from one welding operation to another. Since the average current is changed proportionally and minimum current correction circuits corresponding to the present invention.

The advantage of using the correction circuits minimum current corresponding to the present invention, detected using a step-down chopper circuit corresponding to the present invention, for welding pipes. In the past, the inclination of the working characteristics of the voltage/current used in the welding of pipes, had to do quite steep, so the open-circuit voltage at low currents were relatively high. Through the use of the present invention, theoretical open-circuit voltage can be set quite low for welding by using the working curve with a very gentle slope. By using this gentle slope, when the current is reduced by the operation of welding the pipes, the voltage is gradually increased until, until it reaches the minimum current correction circuits. At this point, the step-down chopper controls the operation of welding in constant current mode, thus creating a significant open-circuit voltage. This use of the present invention eliminates the problem according to this invention, when the current reaches a low level, minimum current correction circuits instantly increases the voltage to any desired level, limited only by the maximum open-circuit voltage of the power source. Increased voltage keeps a set minimum current correction circuits. The invention prevents the arc extinguishing even when welding pipes at a fairly gentle curve of voltage/current.

The primary objective of the present invention to provide an improved step-down chopper DC, used for welding, which can be designed with powerful parallel cascades without the need of balancing currents and without the necessity of increasing the reactance of the individual output chokes or inductors.

Another objective of the present invention to provide the above improved step-down chopper DC, which changes the effective inductance of the arc due to the introduction of the scheme of correction minimum current in step-down chopper circuit, causing current to the welding operation never drops below a given fixed level of current and thus REGZA improvement of the above advanced a step-down chopper DC which does not require significant changes in existing technology, and leads to the excellent work of the reduction circuit breaker when using the many powerful cascades and when welding with a minimum current, which could cause the extinguishing of the arc.

These and other objectives and advantages will become apparent from the following description, given with the accompanying drawings.

Fig. 1 represents a wiring diagram showing the step-down chopper DC, used for arc welding process in which many concurrent powerful modules used to use one feature of the present invention,

Fig. 1A is a conventional block diagram of an alternative input constant current source for use in panyhose the interrupter shown in Fig. 1,

Fig. 2 is a cross section of the core to install the output choke down chopper circuit shown in Fig. 1, and the implementation thus features of the present invention,

Fig. 3 is a conditional Assembly and the block diagram of the feedback circuit in the closed circuit used in the present invention, together with the correction pattern Ostia,

Fig. 3A is a simplified mounting and a block diagram of a feedback system in a closed circuit to provide a control signal for use pulse-width modulator when regulating only current or voltage, and this system can be used with step-down chopper circuit shown in Fig. 1, without the proposed correction circuits shown in Fig. 3,

Fig. 4 is a simplified mounting and a block diagram showing a more specific variant of implementation of the scheme of the correction current is shown in Fig. 3, with automatic regulation of minimum current as a function of the average current of an arc welding operation, generated by the chopper circuit DC shown in Fig. 1,

Fig. 5 represents a circuit diagram showing a preferred specific implementation to obtain the minimum current in the specific embodiment shown in Fig. 4,

Fig. 6 represents a graph of the current pulse, representing the amount of current as a function of time, using the flow chart correction minimum current, which is a part of the present invention,

Fig. 7 represents a graph similar to Fig. 6, Illus is my correction of the specified minimum power,

Fig. 8 is a graph of the current/voltage showing two working curves for the operation of welding the tubes to illustrate the disadvantage of using relatively gently tilt, and

Fig. 9 represents a graph similar to Fig. 8, illustrating the use of the present invention in the operation of welding the pipe and illustrating the advantage of the circuit correction minimum current corresponding to the present invention.

Referring now to the drawings, in which image is shown only to illustrate preferred specific variant of implementation of the present invention and not for purposes of limitation, note that in Fig. 1 shows a multi-stage step-down chopper circuit 10 DC is used as the power source of the welding arc to the direction of the current between the electrode E and the workpiece W. the circuit Breaker 10 includes an input source 12 DC, depicted in the form of the engine 20, operate the generator or synchronous generator with an output winding 22 of the stator, the output of which is isolated by a diode 24. An alternative type of the input constant current source is shown in Fig. 1A, where the rectifier 30 has a three-phase input, including bus 32, 34 is output in Fig. 1. The circuit breaker includes a first switching cascade 50, which includes a switching device 52 in the form of a bipolar transistor with insulated gate (IGBT) or a field-effect transistor (FETS), insulated optically associated with the formation of 54 IGBTs are switched in accordance with the pulses at the input 56 of the feedback generated by the standard optical connector 57 at a frequency in the range of 20 to 40 kHz. In practice, the pulses applied to the input to the shaper 54, proceed to exit 60 pulse-width modulator (PWM) 62 in the circuit 64 control feedback. The pulses on the bus 60 cause the switching device to be opened or closed at a frequency of 20 kHz with a duty cycle at the output 60 of pulse-width modulator, controlled to determine the amount of current directed to the electrode E and the workpiece W. the Multistage circuit breaker 10 includes many powerful parallel modules, of which there are only two. The second module is switching cascade 100 connected in parallel with the first switching cascade 50 and includes a switching device 102 in the form of IGBTs or FETS with isolated optically connected driver 104 IGBT controlled by pulses at the input ity of the two cascades is a decoupling capacitor 110, 112, respectively, to provide current flow from the source 12, when the switching device 52, 102 are non-conductive. When they are conductive, to weld the workpiece through the parallel switches is current determined by the current flowing between the electrode E and the workpiece W. the Diodes 120, 121 overrunning clutch connected in parallel to weld the workpiece and are behind parallel inductors 130, 132 of the first and second switching stages respectively. In accordance with the present invention, the inductors or coils 130, 132 are rigidly connected in the sense transformer connection on a common core 134. By using this idea, the effective inductance of the circuit breaker 10 is, essentially, the inductance of each of the inductors 130, 132, which, generally speaking, have the same inductance. However, they do not need full approval. In addition, the switching device 52, 102 do not require the coordination and balancing of the currents, because the inductance associated with the same core. The output inductance of each cascade is not reduced, as would occur in the parallel scheme, where the choke 130, 132 are separated from each other. Details first OGE perceived by busses 140, 142 and sent to the circuit 64 controls the feedback, as shown in Fig. 1. Shunt 150 current creates in the bus 152, the voltage level, which is a measure of current in the welding arc. Bus 152 is connected to terminal 154 of the circuit 64. In accordance with standard technology, the generator 160 excites a pulse-width modulator (PWM) 162 at a frequency, which is shown equal to 20 kHz; however, this frequency may have different levels within the normal range of frequencies of 20 to 40 kHz. The arc current at terminal 154 or the voltage between buses 140, 142 is compared with the level of the reference voltage at a fixed point, is applied to terminal 170, and this reference voltage is controlled by the bus 174 to the output of the circuit 172 of choice. Manual or automatic selection of a specific operation of arc welding is determined by the logic of the terminals 180, 182 or 184 or switches in the circuit 172. In the depicted specific embodiment, the terminal 180 is chosen when the circuit breaker 10 to be used for welding rod or metal arc welding with consumable electrode in an inert gas environment. Thus, the control power source or circuit breaker continuous current is set so that the current is at a fixed prescribed level C1. Klemm level or with a pre-set angle specified as C2. When welding with a slope used in the welding of pipes and shown in Fig. 8 and 9, the slope of the operating line current and voltage is kept constant at the level specified as C3. This operation arc welding select at terminal 184. As will be explained below, when the select voltage control, you can use a small control current to obtain a predefined angle of inclination of the voltage as a function of current, not constant voltage.

During the operation of the switches in the circuit 172 selection determines the type of arc welding that you want to spend. A Boolean condition on the bus 174 is then compared with either voltage between buses 140, 142, or with the level of current on the bus 152, or a combination of these two parameters. The circuit 64 control feedback includes a pulse-width modulator 62, which is controlled to define the width or the operating cycle of the pulses on the output bus 60 with frequency or switching speed, driven generator 160.

Considering now Fig. 2 in more detail, note that the core 134 is received by the juxtaposition of the pieces of transformer steel with high magnetic permeability in the form of a W-shaped sexual, two inductor connected magnetic connection and provide an effective inductance for the circuit breaker 10 that corresponds to the selected value of the impedance in a separate choke. In accordance with standard technology transformers, half 200, 202 are separated by a small gap g. In practice, separate chokes have an inductive reactance of 150 μh, the invention provides the net reactance of the circuit breaker with two or more cascades of 150 mH. This level was chosen because welding rods requires sufficient stored energy in the inductors to prevent extinction.

By choosing the terminals 180, 182 or 184 the interrupter is operated in accordance with the desired mode. This function is illustrated in more detail in Fig. 3, where the amplifier 220 error has an adjustable input bus 222 and the reference or setpoint input bus 174, going to the positive terminal 234, so that the output signal on bus 226 is a control signal representing a voltage to control the pulse width modulator 62. The amplifier 220 includes a resistor 220a gain control. This is a standard technique for pulse-width modulators used dla, which is a control signal for selecting the operating cycle of the pulse-width modulator, working in unison with generator 160 frequency or speed. To prevent rapid changes in the business cycle, the amplifier 220 includes an integrating circuit 220b, which causes the amplifier 220 to perform the functions of the integrator when the capacitor 220c is connected in parallel with resistor 220a.

The preferred specific implementation shown in Fig.1 has a circuit 64 to control feedback with the input busbars 140, 142, 152, and 174. The same bus is depicted in the upper part of the mounting and the flowchart shown in Fig. 3. This drawing also depicts additional details of the implementation principles of circuit 64 feedback, with unit 230 controls the selecting selects which of the tires 232, 234 or 236 must accept input signals directed to the negative terminal of the regulated input or bus 222 of amplifier 220 errors. Specific bus for control variables input of an error amplifier is chosen, closing one of the switches 232a, 234a or 236a. Summarizing the connection 244 has an exit 246, going to the switch 236a. This control mode voltage at which summarizes seedy tilt, resistor 250 provides a controlled ratio of current Iasumming connection 244. As shown, when the switch 232a is closed, the amplifier 220 errors takes a variable signal representing the arc current, and an integrating circuit 220b is not connected. The output 226 to quickly change the behavior of the pulse-width modulator. Similarly, closure of switch 236a causes the supply voltage of the arc on an adjustable amplifier input errors. Switch 226b connects the circuit 220b, so that the pulse-width modulator gradually changes the mode, and chokes 130, 132 control the growth rate of the current. These two controls voltage or current is shown in block 230' control selection in Fig. 3A. The switching circuit 172 of choice, with inputs 180, 184 and 186, respectively, includes switches 172a, 172b and 172c, appropriate switches, as shown in block 230 control. During the operation of the preferred specific variant of the implementation shown in Fig. 3, and the alternative shown in Fig. 3A, when the switches 232a and 172a are closed, the error amplifier regulates the current of the arc until it reaches a fixed value of C1. Due to the circuit switch 236a, 236b and 172c of the error amplifier regulates sernia C2. To create a slope voltage, use a resistor 250. In addition, we note that during the operation of arc welding with an inclination of the working characteristics as in the welding of pipes, switches 234a, 234b and 272b, which are not shown in simplified form in Fig. 3A, closed. Thus, the slope of the dependence of the voltage from the current control using the constant C3by regulating the voltage at the output 226, which is the control signal for pulse-width modulator 62. A work cycle of the pulses in the tire 62 controls the voltage on the bus 226.

In accordance with a feature of the invention, as shown in Fig. 3 provides a diagram 300 of the correction current. This scheme uses the first entry 302 having a rheostat 304 to regulation set reference point of the minimum current that is used by the input 152 of comparator 310. This comparator is supplied with a shunt resistor 312 high gain, resulting in the output 314 supports the established minimum current on the diode 316, when the arc current in the bus 152 is equal to the adjusted set minimum current, determined by the setting of rheostat 304, or less than this current. Diagram 300 correction allows you to control PE will decrease to a low value signaling the approaching extinction of the arc. At this point, the comparator 310 connects the diode 316 to the output voltage 314 and controls the operation of arc welding so that the rheostat 304 tracked the minimum level of current IMIN. The rheostat controls the effective inductance falling on the site characteristics of the welding cycle. Since the current adjust upward, the arc becomes softer. The arc current never reaches zero; hence, it is very useful for low speed wire feeder. Through the use of the present invention, as shown in Fig. 3, it is possible to integrate the arc voltage and to control the welding operation, as there is a state of low current. Symptom control correction appears in a pre-selected minimum level IMIN. Adjusting the minimum current in the direction of decreasing, you can get more samostyan, unlike softer arc and less spatter when regulating the minimum current in the direction of a higher level. The use of correction circuits minimum current with some standard control feedback in a closed loop regulation provides effective output inductive reactionsolution regulation minimum current IMINfor comparator 310 so that the set current will change at different arc characteristics, such as the speed of the wire. In accordance with this further feature of the present invention, mixing of the arc current minimum current proportionally. In practice, this goal is achieved through the control setpoint minimum current from resistor 304 in accordance with the average arc current on the bus 322. The average arc current derived from the voltage on the bus 152 via filter circuits includes a resistor 330 and capacitor 332. Then the average arc current is multiplied by the inverse number of specified electric element 340, which includes the rheostat 342 with a shoulder 346, managing bus 334, connected directly to the circuit 300 of correction or rheostat 304 shown in Fig. 3. Thus, the regulation of the shoulder 346 rheostat provides regulation of the inverse number for modifications submitted deviations of the average arc current from a selected reference or the minimum level of current IMINat the input of the comparator 310. Through the use of diagrams shown in Fig. 4 and 5, is controlled automatically set to the minimum current and the correction patterns, when the arc current reaches a low level.

The advantage of the circuit 300 correction is illustrated in Fig. 6 and 7. In Fig. 6 step-down chopper circuit 10 has no schema 300 correction and is driven by a circuit shown in Fig. 3A. With the introduction of the scheme 300 correction step-down chopper circuit 10 operates in accordance with Fig. 7. Both examples include a plot 350 DC, followed by a short circuit with the rapid growth of current indicated by the plot or line 352. The speed of ascent line 352 controls the inductor 130, 132, because the duty cycle of pulse-width modulator does not change, because the switch 236b includes an integrating circuit 220b. After a break of a short circuit, on the site of the recession 354 current gradually decreases at the stage control with constant voltage. In the absence of a schema 300 correction section recession 354 may take the shape of the curve 354a, shown in Fig. 6. On this curve the current plot of the decay reaches the zero value, and this leads to the unstable condition of the arc. Through the use of circuit 300 correction operation step-down chopper circuit is converted to work with a fixed set minimum current IMINor adjustable set min is inogo state of the arc. Through the use of an adjustable predetermined minimum current is very active management of the arc. In both cases, the effective output inductance of the circuit breaker 10 is modified so that would be impossible in a system that has no schema correction.

Another advantage of the circuit 300 is implemented when the step-down Converter 10 is used for welding of pipes, where current and voltage change of the working characteristic. The slope is determined by the circuit switch 172b, 234a and 234b. As is known, the operating characteristic voltage/current for the operation of welding the pipes should be relatively steep, as shown by line 360 in Fig.8. In the presence of steep operating characteristics with decreasing voltage increases, so that when there is no current there is, essentially, the open-circuit voltage. It is advantageous to work with a relatively gentle slope of the working characteristics, as represented by line 362 in Fig. 8 and line 362 in Fig. 9. When working on this line or curve at zero current there is a lack of open-circuit voltage from the power source. This is an inefficient operation of welding. Through the use of circuit 300 correction operation welding ensures the gradual change in voltage with change in arc current. When the arc current is reduced to the minimum level of IMINused in the circuit 300, the circuit 300 correction causes the down-regulation of the breaker until it reaches a minimum voltage. This is shown by plot line 374 370 that the maximum open circuit voltage for the power source is realized while maintaining a predetermined minimum current, resulting arc is stabilized at low currents.

It is possible to make various changes in the circuits shown on the drawings, without departing from the scope of the claims of the present invention.

1. Chopper constant current for arc welding, comprising an input constant current source, the first switching stage with the first switching device and the first inductor while the first stage is executed to selectively connect the input DC source to the electrode and the workpiece with a controllable duty cycle and switching speed, the second switching stage, with the second switching device and the second inductor, the second stage is executed to selectively connect the input DC is irate pulse width modulator to control the specified duty cycle and switching speed in accordance with a control signal, characterized in that it contains magnetically-permeable core, and means for creating a transformer connection specified first and second choke by winding the above first and second chokes on the specified core.

2. The circuit breaker DC under item 1, characterized in that the constant current source is a generator driven by the engine.

3. The circuit breaker DC under item 2, characterized in that the breaker has only said first and said second switching stages.

4. The circuit breaker DC under item 2, characterized in that the switching devices are bipolar transistors with insulated gate (IGBT).

5. The circuit breaker DC under item 1, characterized in that the switching devices are field effect transistors (FETS).

6. The circuit breaker DC under item 1, characterized in that the switching devices are bipolar transistors with insulated gate (IGBT).

7. The circuit breaker DC under item 1, characterized in that the constant current source is a rectifier having an AC input and DC output.

8. Perushim the difference between the voltage between the said electrode and the workpiece and a reference signal, which is the indicator of the selected desired arc voltage.

9. The circuit breaker DC under item 8, characterized in that it includes a correction system for limiting the control signal value that supports at least the minimum current between the electrode and the workpiece.

10. The circuit breaker DC under item 9, characterized in that the correction pattern includes means for regulating the specified minimum current.

11. The circuit breaker DC under item 9, characterized in that the correction pattern includes tools for managing the specified minimum current as a function of the average current between the said electrode and the workpiece.

12. The circuit breaker DC on p. 11, wherein the correction pattern includes means for regulating the mean current.

13. The circuit breaker DC under item 1, characterized in that the control signal is an error signal representing the difference between the current between the said electrode and the workpiece and a reference signal, which is the indicator of the selected desired arc current.

14. The circuit breaker DC on p. 13, otoribashi at least the minimum current between the electrode and the workpiece.

15. The circuit breaker DC under item 14, characterized in that the correction pattern includes means for regulating the specified minimum current.

16. The circuit breaker DC under item 14, characterized in that the correction pattern includes tools for managing the specified minimum current as a function of the average current between the said electrode and the workpiece.

17. The circuit breaker DC under item 16, characterized in that the correction pattern includes means for regulating the specified function.

18. The circuit breaker DC under item 1, characterized in that the control signal is a control signal for a voltage and current between the electrode and the workpiece.

19. The circuit breaker DC under item 18, characterized in that it includes a correction pattern for limiting the control signal value that supports at least the minimum current between the electrode and the workpiece.

20. The circuit breaker DC under item 19, characterized in that the correction pattern includes means for regulating the specified minimum current.

21. The circuit breaker DC for d is the device and choke, in this case, the specified stage is executed to selectively connect the input DC source to the electrode and the workpiece with a controllable duty cycle and switching speed and pulse-width modulator to control the specified duty cycle and switching speed in accordance with a control signal, characterized in that it contains a correction pattern, made with the possibility of limiting the control signal value that supports at least the minimum current between the said electrode and the workpiece.

22. The circuit breaker DC on p. 21, characterized in that the correction pattern includes means for regulating the specified minimum current.

23. The circuit breaker DC on p. 21, characterized in that the correction pattern includes tools for managing the specified minimum current as a function of the average current between the said electrode and the workpiece.

24. The circuit breaker DC on p. 23, characterized in that the correction pattern includes means for regulating the mean current.

 

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8 cl, 8 dwg

FIELD: electrical engineering.

SUBSTANCE: proposed diode-transistor bridge relates to electrical engineering, particularly to electrical machines and can be used in structural couplings with magnetic bearings. Diode-transistor bridge comprises supply diagonal and load diagonal incorporating at least one inductor coil (8). Note that throttle (7) is additionally included in load diagonal, RC-circuit (9) being connected in parallel to said throttle. Capacitor (12) and power source are connected in said supply diagonal, the latter being connected via separating diode (13). Transistors (5,6) connected into bridge arms have no common connection point. Storage capacitor (12), throttle (7) with RC-circuit (9) and separating diode (13) connected in the diode-transistor bridge in proposed manner, allows a notable reduction in consumed power of the bridge, diametre of conductors connected to power supply and its overall dimensions.

EFFECT: higher reliability, reduced dependence of source weight-and-size upon consumed power.

1 dwg

FIELD: electrical engineering.

SUBSTANCE: integrated power supply voltage converter is intended for efficient conversion of power supply voltage for low-capacity and low-voltage devices that operate from batteries and accumulators to voltages that are less than voltages of chemical power supply sources. Circuit of integrated power supply voltage includes the following components: substrate for circuit arrangement, output unit connected to power supply source and generating output signal, control unit, which controls output unit by means of feedback, unit of low-frequency filter, function of which is to level output signal received from output unit, control unit is equipped with source of reference voltage, voltage divider, clock signal generator and error detector, besides voltage divider transforms signal from reference voltage source and sends it to input of error detector, where signal is also supplied from output unit as well, and further from error detector control signal arrives to permitting input of clock signal generator, and output unit is arranged as based on switched capacitors in the form of two cascades connected in parallel, the first of which comprises capacitor (17), one p-channel transistor (18) and three n-channel transistors (19, 20, 21), the second cascade comprises capacitor (22), p-channel transistor (23) and three n-channel transistors (24, 25, 26), besides transistors of output unit cascades are controlled by two paraphrase signals from clock signal generator "input 1" and "input 2" so that "input 2" signal is sent to transistors (18, 20, 21) and (24), and signal "input 1" is sent to transistors (19, 23, 25, 26), transistors are connected so that depending on level of "input 1" and "input 2" signals, which may either be high or low, at the moment of time, when "input 1" signal is of high level, and signal "input 2" is of low level, current passes through transistors (18, 19) and capacitor (17) from power supply source to output, besides capacitor (17) is in charging phase, and through transistors (25, 26) and capacitor (22) from common bus to output, besides, capacitor (22) is in discharging phase, and at the moment of time, when "input 1" signal is of low level, and signal "input 1" is of high level, current passes through transistors (20), (21) and capacitor (17) from common bus to output, besides, capacitor (17) is in discharging phase, and through transistors (23, 24) and capacitor (22) from power supply source to output, besides capacitor (22) is in charging phase, and at the same time, both in charging or discharging phase of capacitors (17) and (22) current flows in one direction towards outlet of output unit.

EFFECT: achievement of low output voltages and improved efficiency factor at low energy consumption.

7 dwg

FIELD: radio engineering.

SUBSTANCE: voltage switching unit with protection against current overload includes electronic switch which supplies the power to load unit and to overload freezing unit. Overload freezing unit freezes the activation of electronic switch at initial supply of input voltage and provides the deactivation of electronic switch when the current is higher than the specified one. Additionally introduced shaper of delayed pulse unlocks the electronic switch, provides the specified delay relative to the supply of input voltage.

EFFECT: improving reliability of the device owing to excluding the current stabilisation mode at any kinds and modes of load, and enlarging functional capabilities owing to tuning of current commutation time relative to supply of input voltage.

2 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: in a stabiliser, comprising an input capacitor, a transistor, a diode, a throttle, a current sensor and an output capacitor, parallel to the input capacitor there are the following components connected in series - an upper stabilitron, a current stabiliser and a lower stabilitron, joined to a negative pole of the input capacitor, parallel to the upper stabilitron there are the following components connected - an interlocking device, connected to an upper comparator, an operational amplifier and a reference voltage divider, a sawtooth oscillator, an upper comparator and an operational amplifier, and a bridge circuit is connected in parallel to the lower stabilitron, including a transistor of an optical transistor and three resistors, and also a lower comparator. At the same time devices are used for galvanic isolation of control elements.

EFFECT: expansion of input voltage range, simplification, reduced cost, increased reliability and convenience of the stabiliser operation.

4 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: protection circuit of the power supply unit of a dc voltage apparatus is installed at the output of the power supply unit, and between the positive terminal (3) of the power supply unit and the positive terminal (1) of said apparatus there is a switching element (S1) and an inductor (L1), which is connected between the switching element (S1) and the positive output terminal (1), wherein the inductor (L1) on its side connected to the positive output terminal (1) is also connected to the an output capacitor (C2), and the side of the inductor (L1) connected to the switching element (S1) is connected to a diode (D1), which is connected in parallel to the output capacitor (C2) n the cathode side, and there is also a device for controlling the switching element (S1), which includes the switching element (S1) depending on current measured in the protection circuit.

EFFECT: designing an apparatus which, as a result of connecting units when the apparatus is operating, the absence of current harmonics is determined, and therefore undervoltage on the conductor line.

16 cl

FIELD: electricity.

SUBSTANCE: invention is a device with supply from a solar battery, which includes a battery, at least one photoelectric element (which may be a part of a solar module comprising multiple photoelectric elements) and a DC-perceptive AC device, such as a compact fluorescent lamp. The device with supply from a solar battery may also include the first DC-DC converter, which receives the first electric signal from at least one photoelectric element and provides a charging signal to a battery, and the second DC-DC converter, which receives the second electric signal from a battery and provides for a DC signal of DC supply to the DC-perceptive AC device.

EFFECT: higher efficiency factor.

19 cl, 3 dwg

FIELD: electricity.

SUBSTANCE: step-up voltage converter comprises an input circuit with a choke in one of branches, two power keys, two diodes, and a starting key with a resistor shunting it and two in-series output capacitors. In order to improve reliability of semiconductor elements and prevention of the core saturation upon supply of input voltage should be performed in four stages. Unbalanced conditions of the converter operation are eliminated by introduction into the scheme of two auxiliary keys controlled by two auxiliary drivers and two operating amplifiers (OA). A resistor is connected in series with each auxiliary key and each operating amplifier contains series circuits, which consist of a diode and resistor thus ensuring hysteresis of connection and disconnection of the auxiliary keys.

EFFECT: high reliability.

5 dwg

FIELD: electricity.

SUBSTANCE: invention relates to the field of electrical equipment and can be used in digital control systems of DC voltage converters with the function of suppression of the hazardous oscillations of output voltage occurring at a certain set of parameters of the system. In the nonlinear dynamics control system the control system consisting of the main subsystem and the control auxiliary subsystem, approximators on the basis of neural networks is connected to the power part of the converter. The converter control signal provides the stabilization of average value of output voltage. In the system the correction of error signal is provided, thus the stabilization of the design dynamic mode (1 cycle) is provided.

EFFECT: ensuring of pre-set nonlinear dynamic properties of the system and pre-set parameters of speed and accuracy of output voltage stabilization in case of refusal from parametrical synthesis.

3 dwg

FIELD: electricity.

SUBSTANCE: direct-current voltage converter comprises control field-effect transistor, which gate is shunted by parallel circuit from counterconnected first diode and first resistor while its drain is connected to anode connection point of switching diode and the first output of choke, which second output is connected to the first input pin joined to source of the control field-effect transistor and the first output pin connected through output capacitor to cathode connection point of switching diode, the second output pin and the first output pin of the output voltage divider, which second output is connected to the first output pin meanwhile the midpoint is connected to measuring input of the control unit, which common leg is connected to the first output pin, emitter follower, which output pin is connected to the first output of the second resistor. The circuit is featured by introduction of a coupling capacitor connected between the second output of the second resistor and gate of the field-effect transistor, the first transistor with load resistor in the collector circuit and auxiliary capacitor connected between outputs of the collector and emitter of the first transistor, which base is connected to output pin of the control unit, emitter is connected to the first output pin while collector - to input pin of the emitter follower. At that in the suggested device the control unit may consist, for example, of pulse generator, which output is coupled to input of saw-tooth voltage shaping unit and to the first input of comparator circuit, which second input is coupled to output of saw-tooth voltage shaping unit and its third input is coupled to output of feedback amplifier, which input is connected to input pin of the control unit and its second input is connected to output of the reference element. In operating mode at large pulse ratio of control voltage at the gate of field-effect transistor (low duration of gating pulses) due to introduction of an auxiliary capacitor the control field-effect transistor starts operation in linear mode limiting reduction in duration of control voltage thus preventing loss in stability of regulation by DC voltage stabiliser.

EFFECT: reliability improvement.

3 cl, 3 dwg

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering and can be used in load time division multiple access systems. Power supply with USB interface comprises: USB interface, smooth switching circuit and DC/DC conversion circuit, which are connected in series. From output of DC/DC conversion circuit power is supplied to loading time-division multiple access system. Power supply source also comprises a capacitor, first end of which is connected between smooth switching circuit and DC/DC conversion circuit, and second end is grounded. Said capacitor is used for limitation of input current of DC/DC conversion circuit. Value of capacitor is selected in accordance with voltage on capacitor, when loading time-division multiple access system is operating or not operating, maximum current allowable for output via a USB interface, input voltage of DC/DC conversion circuit, voltage and current required by load time division multiple access system, and period of operation of load time-division multiple access system.

EFFECT: technical result consists in compensation of power at reduced capacitance in circuit of connector, providing compensation of power, ensuring working parameters of power supply source with USB interface.

8 cl, 8 dwg

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