JP2000287441A - Two output chopper circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reducing the number of parts when a single output chopper is changed into a two output chopper. SOLUTION: A serial circuit of an inductor 4 and a first switching element 3 is connected in parallel with an input power supply 1, and a serial circuit of a first rectifying element 6 and a first capacitor 8 is connected in parallel with the first switching element 3 in a chopper circuit. A second switching element 2 is connected between the input power supply 1 and the inductor 4. A serial circuit of a second rectifying element 7 and a second capacitor 9 is connected in parallel with a serial circuit of the inductor 4 and the first switching circuit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

The present invention relates to a circuit configuration of a two-output chopper circuit.

[Prior art]

FIG. 10 simply shows a conventional one-output chopper as two
FIG. 9 is a circuit diagram of an output chopper. Here, 1 is an input power supply, 2 and 3 are switch elements, 4 and 5 are inductors,
6 and 7 are rectifying elements, and 8 and 9 are capacitors. The voltages of the capacitors 8 and 9 are V1 and V2. 3, 4, 6, and 8 are provided with boost choppers. This allows the capacitor
8, a DC voltage V1 is obtained. 2, 5, 7, and 9 constitute a step-up / step-down chopper. This allows the capacitor 9
To obtain a DC voltage V2.

The problem shown in FIG. 10 is that the number of parts increases to increase the size. In the case of single output, the parts are 3, 4, 6,
8 points. In order to make this into two outputs, usually, FIG.
The parts 2, 5, 7, 9 are increased as shown in FIG. By doing so, a single output chopper can be replaced with a two-output chopper, and the output can be increased. However, in this method, the number of components 2, 5, 7, and 9 increases, and the number of components doubles to eight. With increasing demands for miniaturization and weight reduction, it is often not possible to increase the number of components.

[Problems to be solved by the invention]

As described above, conventionally, since the output of the chopper circuit is increased from a single output to two outputs, the number of components has been significantly increased. SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-output chopper with a minimum number of components when increasing the output of a chopper circuit from a single output to two outputs.

[Means for Solving the Problems]

In the present invention, the number of components is reduced by sharing the two inductors 4 and 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an embodiment of the first aspect of the present invention. In FIG. In a chopper circuit in which a series circuit of a first rectifying element 6 and a first capacitor 8 are connected in parallel with a third switch element 3, a second switch element 2 is connected between an input power supply 1 and an inductor 4, A series circuit of the rectifying element 7 and the second capacitor 9 is connected in parallel to a series circuit of the inductor 4 and the first switch element 3. FIG. 6 is a diagram showing an embodiment of the second aspect of the present invention.
And a series circuit of a first switch element 3 and a series circuit of a first rectifying element 6 and a first capacitor 8 connected in parallel with the first switch element 3. The second switch element 2 is connected between the second switch element 2 and the inductor 4, and a series circuit of the second rectifier element 7 and the second capacitor 9 is connected in parallel to the second switch element 2. FIG. 9 shows a more specific embodiment of the present invention, in which a series circuit of a third switch element 10 and a fourth switch element 11 is connected in parallel to a series circuit of a capacitor 8 and a capacitor 9 in FIG. And the first capacitor 8
A series circuit consisting of a second inductor 12 and a third capacitor 13 is connected between a connection point of the second capacitor 9 and a connection point of the third switching element 10 and a connection point of the fourth switching element 11. And

Next, the circuit operation of the present invention will be described. FIG. 2 shows operation waveforms of the circuit of FIG.

Before describing the circuit operation, a time and a state are defined. One cycle is divided into four states by a combination of ON and OFF of the switch elements 2 and 3. The start time and end time of each state, and ON / OFF of the switch elements 2 and 3 are defined as follows. State 1 is from time t0 to t1. In state 1, both switch elements 2 and 3 are on. State 2 is from time t1 to t2. In state 2, switch element 2 is off and switch element 3 is on. State 3 is from time t2 to t3. In state 3, both switch elements 2 and 3 are on. State 4 is from time t3 to t4. In state 4, switch element 2 is on and switch element 3 is off. Next, the operation will be described in order from state 1.

In state 1, both switch elements 2 and 3 are on. As a result, no current flows because the rectifying elements 6 and 7 are reverse-biased. Therefore, the equivalent circuit in state 1 is as shown in FIG. An input voltage is applied to the inductor 4, and the current increases linearly.

In state 2, switch element 2 is off and switch element 3 is on. When the switch element 2 is turned off at the time t1, the inductor 4 operates so as to continue to flow the current in the same direction as before, so that the inductor 4 → the switch element 3 → the capacitor 9 → the rectifying element 7 → the inductor.
Current flows through route 4. On the other hand, since the switching element 3 remains on, the rectifying element 6 is reverse-biased. Therefore, the equivalent circuit at this time is as shown in FIG. The inductor 4 is clamped at the output voltage V2, and its current decreases linearly.

In state 3, the on / off state of the switch is the same as in state 1, and the operation is the same. The current of the inductor 4 increases linearly.

In state 4, switch element 2 is on and switch element 3 is off. When the switching element 3 is turned off at the time t3, the inductor 4 operates so as to continue to flow the current in the same direction as before, so that the inductor 4 → the rectifying element 6 → the capacitor 8 → the input power supply 1 → the switching element 2
→ Current flows through the route of the inductor 4. On the other hand, since the switching element 2 remains on, the rectifying element 7 is reverse-biased. Therefore, the equivalent circuit at this time is shown in FIG.
Becomes The inductor 4 is clamped at (output voltage V1−input voltage), and its current decreases linearly. One cycle ends when the switch element 3 is turned on again at the time t4, and the state returns to the state 1 again.

As is clear from the above description, state 1,
2 is an operation of the step-up / step-down chopper, and states 3 and 4 are operations of the step-up chopper. Therefore, it can be said that the present invention is a circuit in which two choppers are integrated.

The output voltages V1 and V2 are represented by the following equations.
Where Vi is the input voltage, Li is the inductance of the inductor 4, T is the switching cycle, ton ₁ is the on time of the switch element 3, ton ₂ is the on time of the switch element 2, Io ₁ is the output current of V1, and Io ₂ is the output current of V1. This is the output current of V2. The flow directions of Io ₁ and Io ₂ are shown in FIG.

(Equation 1)

(Equation 2) As can be seen from Expressions 1 and 2, it is possible to control the output voltage by controlling ton ² / T. For example, T
If a constant that is fixed frequency, the output voltage is proportional to the ton ^2.

FIG. 6 shows another circuit configuration of the present invention, in which circuit portions and components having the same reference numerals as those in FIG. 1 have the same contents. As shown in FIG. 6, even if the connection between the middle points of the capacitors 8 and 9 is changed to the plus side of the input power supply 1 instead of the minus side, the operation can be performed without any problem. In this case, the operation is reversed, and states 1 and 2 are operations of the step-up chopper, and states 3 and 4 are operations of the step-up / step-down chopper. This is because the route through which the current flows changes. Since the operations in states 1 and 3 are the same in both FIG. 1 and FIG. 6, the description is omitted. In state 2, the current flows through the route of inductor 4 → switch element 3 → input power supply 1 → capacitor 9 → rectifier element 7 → inductor 4. FIG. 7 shows an equivalent circuit at this time.
Since the input power is included in the route, it is understood that this is the operation of the boost chopper. In state 4, the current flows through the route of the inductor 4, the rectifier 6, the capacitor 8, the switch 2, and the inductor 4. FIG. 8 shows an equivalent circuit at this time. Since the input power supply is not included in the route, it is understood that this is the operation of the step-up / step-down chopper.

The output voltage at this time is as follows because the step-up and step-up and step-down are switched.

(Equation 3)

(Equation 4)

As described above, the connection between the middle points of the capacitors 8 and 9 may be either on the plus side or the minus side of the input power supply 1. This means that the circuit of the present invention can be used regardless of whether the input power is positive or negative.

FIG. 9 shows a more specific embodiment of the present invention. Circuit parts and components having the same reference numerals as those in FIG. 1 have the same contents.
This embodiment is an inverter in which one end of an output is connected to one end of an input, and is an example of a signal generator for ringing a telephone called a ringer. The AC output is used by being superimposed on the DC. As compared to FIG.
11, an inductor 12, and a capacitor 13 are added. These components constitute a half-bridge inverter. In the operation, the DC voltages V1 and V2 are switched by the switch elements 10 and 11, and converted into a set of rectangular waves corresponding to a required AC waveform. An AC voltage is obtained by shaping the waveform of this rectangular wave train through a filter composed of an inductor 12 and a capacitor 13. In FIG. 9, the AC output is connected to the negative side of the DC input, which is a method called “−48 V superposition”. Telecommunications equipment is so named because it uses DC48V with positive ground. on the other hand,
There is also a method of connecting to the positive side of the DC input.
It is called "superposition." As described above, in the circuit configuration of the present invention, the midpoint of the capacitors 8 and 9 may be connected to the plus side or the minus side of the input power supply.
Therefore, just by providing switching means, one device
It can handle both -48V superimposition and G superimposition. This is an example in which the features of the present invention are successfully used.

As described above, when the present invention is used, a single output can be changed to two outputs while suppressing an increase in the number of parts.
It has great industrial applicability.

[Brief description of the drawings]

FIG. 1 is a circuit configuration of the present invention.

FIG. 2 is an operation waveform of FIG.

FIG. 3 is an equivalent circuit of states 1 and 3 in FIG. 1;

FIG. 4 is an equivalent circuit of state 2 in FIG.

FIG. 5 is an equivalent circuit of state 4 in FIG. 1;

FIG. 6 shows another circuit configuration of the present invention.

FIG. 7 is an equivalent circuit of state 2 in FIG. 6;

8 is an equivalent circuit of state 4 in FIG.

FIG. 9 shows an embodiment of the present invention.

FIG. 10 shows a conventional circuit configuration.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 input power supply 2 switch element 3 switch element 4 inductor 5 inductor 6 rectifier 7 rectifier 8 capacitor 9 capacitor 10 switch element 11 switch element 12 inductor 13 capacitor

Claims (3)

[Claims] A series circuit of an inductor and a first switch element is connected in parallel to an input power supply, and a first rectifying element and a first capacitor are connected in parallel to the first switch element. In a chopper circuit in which series circuits are connected in parallel,
A second switch element 2 is connected between the input power supply 1 and the inductor 4, and a series circuit of a second rectifier element 7 and a second capacitor 9 is connected to a series circuit of the inductor 4 and the first switch element 3. A two-output chopper circuit, which is connected in parallel to the chopper. 2. A series circuit of an inductor 4 and a first switch element 3 is connected in parallel with an input power supply 1, and a first rectifier element 6 and a first capacitor 8 are connected in parallel with the first switch element 3. In a chopper circuit in which series circuits are connected in parallel,
A second switch element 2 is connected between the input power supply 1 and the inductor 4, and a series circuit of a second rectifier element 7 and a second capacitor 9 is connected in parallel to the second switch element 2. Features a two-output chopper circuit. 3. A series circuit of a third switch element 10 and a fourth switch element 11 is connected in parallel with a series circuit of the first capacitor 8 and the second capacitor 9; A series circuit composed of a second inductor 12 and a third capacitor 13 was connected between a connection point of the second capacitor 9 and the second capacitor 9 and a connection point of the third switch element 10 and the fourth switch element 11. 3. The two-output chopper circuit according to claim 1, wherein: