JPH07219652A - Power unit - Google Patents

Abstract

PURPOSE:To easily provide the power unit which has a zero variable constant voltage or zero variable constant current function at a low price. CONSTITUTION:A DC stabilized power source 1 outputs a DC output voltage Vout in a stable state. This DC stabilized power source 1 is equipped with a variable output voltage terminal TRM which varies the set value of the output voltage Vout. A zero variable control module 4 which supplies a variable command voltage is connected to the variable output voltage terminal TRM. Consequently, the existent DC stabilized power source 1 is only equipped with the zero variable control module 4 to add the zero variable constant voltage or zero variable constant current function.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device capable of variably controlling an output voltage from zero volt and a power supply device capable of variably controlling an output current from zero ampere.

[0002]

2. Description of the Related Art Generally, a power supply device capable of variably controlling an output voltage from zero volt and a power supply device capable of variably controlling an output current from zero ampere are referred to as a zero variable constant voltage low current power supply device, and are referred to as semiconductors, car electronics, It is effectively used in manufacturing departments that require large capacity for electronic parts. In such a power supply device, a switching circuit including a DC / DC converter and the like, a zero variable constant voltage control circuit and a zero variable constant current circuit are incorporated in the same case to operate a volume that varies output voltage and output current. As a result, the output voltage or the output current is supplied to the predetermined set value in a stable state.

[0003]

In the power supply device of the prior art described above, since each circuit is incorporated in the same case as described above, it is necessary to design the entire device for exclusive use. Therefore, the design takes a huge amount of time and cost until the product is completed, and there is a drawback that a power supply device having such a zero variable constant voltage or zero variable constant current function cannot be easily and inexpensively produced.

Therefore, in view of the above problems, it is an object of the present invention to provide a power supply device having a zero variable constant voltage or zero variable constant current function simply and inexpensively.

Another object of the present invention is to provide a power supply device having a zero variable constant voltage and a zero variable constant current function at the same time simply and inexpensively.

Another object of the present invention is to provide a power supply device capable of performing a zero variable constant voltage control for a DC stabilized power supply with a simple circuit configuration.

Another object of the present invention is to provide a power supply device capable of performing a zero variable constant current control for a stabilized DC power supply with a simple circuit configuration.

[0008]

SUMMARY OF THE INVENTION The present invention provides a stabilized DC power supply having an output voltage variable terminal for varying a set value of a DC output voltage, and a zero for supplying a variable command voltage to the output voltage variable terminal. And a variable control module.

It is preferable that the zero variable control module includes a zero variable constant voltage control circuit that maintains the output voltage from the DC stabilized power supply at a predetermined set value. Further, it is preferable that the zero variable control module includes a zero variable constant current control circuit that maintains an output current from the DC stabilized power supply at a predetermined set value. In this case, the zero variable control module may include both the zero variable constant current control circuit and the zero variable constant voltage control circuit.

The zero variable constant voltage control circuit includes a voltage detection circuit for detecting the output voltage of the DC stabilized power supply,
The first reference voltage supply circuit whose setting value can be changed by the first variable resistor is compared with the detection signal of the voltage detection circuit and the reference voltage of the first reference voltage supply circuit, and the comparison result is shown. It is preferable that the output voltage variable terminal comprises a first error amplifier supplied as a command voltage. Further, the zero variable constant current control circuit includes a current detector that detects an output current of the stabilized direct current power supply, a second reference voltage supply circuit whose setting value can be changed by a second variable resistor, and It is preferable that the detection signal of the current detector and the reference voltage of the second reference voltage supply circuit are compared with each other and the comparison result is supplied to the output voltage variable terminal as a command voltage.

[0011]

With the above structure, the output from the DC stabilized power supply can be set to an arbitrary value from zero volts or zero amperes by simply applying a predetermined variable command voltage from the zero variable control module to the output voltage variable terminal of the DC stabilized power supply. It can be changed to a set value in a stable state.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In the circuit configuration diagram shown in FIG. 1, reference numeral 1 is a general-purpose DC stabilized power supply that converts a DC input voltage Vin applied between input terminals 2 and 2A into a DC output voltage Vout. Is a DC / DC converter including a switching element and a transformer (not shown), and an output voltage Vout from the DC / DC converter.
A feedback circuit is provided to stabilize the voltage at a predetermined set value. Further, the stabilized DC power supply 1 is provided with an output voltage variable terminal TRM capable of externally varying the set value of the output voltage Vout. Variable output voltage terminal T
RM is an output voltage Vou built in the DC stabilized power supply 1.
When a command voltage is supplied to the output voltage variable terminal TRM from the outside by being connected to an output voltage detection circuit (not shown) that detects t, the reference voltage in the output voltage detection circuit is set according to the command voltage. It has become. That is, when the command voltage is raised, the set value of the output voltage Vout also rises, and when the command voltage is dropped, the set value of the output voltage Vout also falls. The output voltage Vout is supplied from the stabilized DC power supply 1 to the load (not shown) and the like via the output terminals 3 and 3A.

Reference numeral 4 denotes an external zero variable control module which is provided separately from the stabilized DC power supply 1 and supplies a variable command voltage to the output voltage variable terminal TRM. The zero variable control module 4 includes a zero variable constant voltage control circuit 5 for keeping the output voltage Vout from the stabilized DC power supply 1 at a predetermined set value, and an output current Iou flowing through the output voltage Vout line.
The zero variable constant current control circuit 6 for keeping t at a predetermined set value is provided as an original feedback loop. In the present embodiment, the zero variable constant voltage control circuit 5 and the zero variable constant current control circuit 6 are both provided, but the zero variable control module 4 may be configured by either one of the circuits. The zero variable constant voltage control circuit 5 controls the output voltage Vo from the stabilized DC power supply 1.
voltage detection circuit 7 for detecting ut, a first reference voltage supply circuit 9 having a first variable resistor 8 that can be operated from the outside, a detection signal of the voltage detection circuit 7, and a first reference voltage supply It is configured by a first error amplifier 10 which compares the reference voltage of the circuit 9 and supplies the comparison result to the output voltage variable terminal TRM as a command voltage. The voltage detection circuit 7 is
It consists of a series circuit of voltage dividing resistors 11 and 12 connected between the output voltage Vout line and the ground line.
The voltage from the connection point of 1 and 12 is the error amplifier as a detection signal.
0 applied to one input terminal. Further, the reference voltage supply circuit 9 is composed of a series circuit of a fixed resistance 13 for voltage division and a DC power supply 14 together with the variable resistance 8 described above, and the voltage at the connection point of the variable resistance 8 and the fixed resistance 13 causes an error as a reference voltage. amplifier
Applied to the other input terminal of 10. The set value of the reference voltage of the reference voltage supply circuit 9 can be changed by operating the variable resistor 8. Also, the error amplifier 10
Of the diode 15 whose anode side is connected to the output terminal of the error amplifier 10 between the output terminal and the variable output voltage terminal TRM.
Is provided. The diode 15 is provided to prevent the current from flowing into the output voltage variable terminal TRM side when the current from the output terminal of the error amplifier 10 reaches a predetermined level or higher.

On the other hand, the zero variable constant current control circuit 6 includes a shunt resistor 21 as a current detector for detecting the output current Iout from the stabilized DC power supply 1 and a second shunt resistor 2 which can be operated from the outside.
Second reference voltage supply circuit 23 including the variable resistor 22 of FIG. 1 and the detection signal of the shunt resistor 21 and the reference voltage of the reference voltage supply circuit 23 are compared, and the comparison result is output voltage variable terminal TR.
A second error amplifier 24 is supplied to M as a command voltage. The detection signal from the shunt resistor 21 is applied to one input terminal of the error amplifier 24, but the reference voltage supply circuit
23 is composed of a series circuit of a variable resistor 22, a fixed resistor 25 for voltage division, and a DC power supply 26, and the voltage at the connection point between the variable resistor 22 and the fixed resistor 25 is applied to the other input terminal of the error amplifier 24 as a reference voltage. To be done. The reference voltage of this reference voltage supply circuit 23 is
By operating the variable resistor 22, its set value can be changed. Further, a diode 27 whose anode side is connected to the output terminal of the error amplifier 24 is provided between the output terminal of the error amplifier 24 and the output voltage variable terminal TRM. The diode 27 has a variable output voltage terminal TR when the current from the output terminal of the error amplifier 24 reaches a predetermined level or higher.
It is provided to prevent the inflow of current to the M side.
In the embodiment, the current detector is a shunt resistor 21
However, it is also possible to use, for example, a current transformer with less output loss.

Next, the operation of the above configuration will be described. When the input voltage Vin is applied between the input terminals 2 and 2A, the stabilized DC power supply 1 supplies a predetermined output voltage Vout from the output terminals 3 and 3A in a stable state. Output voltage V
The voltage setting value of out is determined by the voltage level of the output voltage variable terminal TRM, and as the voltage level of the output voltage variable terminal TRM decreases, the voltage setting value of the output voltage Vout also decreases. There is. When the zero variable control module 4 is connected to the stabilized DC power supply 1 having such an output voltage varying function, the output voltage Vo from the stabilized DC power supply 1 is adjusted in the zero variable constant voltage control circuit 5.
ut is divided by the resistors 11 and 12 of the voltage detection circuit 7,
While being output as a detection signal to the input terminal of the error amplifier 10, in the zero variable constant current control circuit 6, the output current Iout from the stabilized DC power supply 1 is output to the input terminal of the error amplifier 24 as a detection signal by the shunt resistor 21. To be done.
Then, the zero variable constant voltage control circuit 5 compares the detection signal from the voltage detection circuit 7 with the reference voltage from the reference voltage supply circuit 9 in the error amplifier 10, and outputs the command voltage of the voltage level based on the comparison result. By applying the voltage to the voltage variable terminal TRM, constant voltage control is performed so that the output voltage Vout becomes a constant value. The zero variable constant current control circuit 6 is also an error amplifier.
At 24, the detection signal from the shunt resistor 21 is compared with the reference voltage from the reference voltage supply circuit 23, and the command voltage of the voltage level based on the comparison result is applied to the output voltage variable terminal TRM to change the output voltage Vout line. Output current I
Constant current control is performed so that out has a constant value.

In this series of constant voltage / constant current control,
The variable output voltage Vout is achieved by operating the variable resistor 8 of the zero variable constant voltage control circuit 5. That is, when the variable resistor 8 is operated to decrease the reference voltage applied to the input terminal of the error amplifier 10, the command voltage output from the output terminal of the error amplifier 10 to the output voltage variable terminal TRM also decreases. Therefore, the output voltage Vout from the stabilized DC power supply 1 drops, and the constant voltage control by the zero variable constant voltage control circuit 5 is continued under this lowered voltage setting value. In this case, the variable resistor 8 is operated to output the output voltage Vo.
It is possible to variably control ut to approximately zero volt. Conversely, when the variable resistor 8 is operated to increase the reference voltage applied to the input terminal of the error amplifier 10, the output voltage Vout also increases, but when the command voltage from the error amplifier 10 exceeds a certain voltage level, The diode 15 prevents the current from flowing into the output voltage variable terminal TRM side, and consequently prevents the output voltage Vout from rising without limitation.

Further, the variable resistance of the zero variable constant current control circuit 6
When 22 is operated to decrease the reference voltage applied to the input terminal of the error amplifier 24, the command voltage output from the output terminal of the error amplifier 24 to the output voltage variable terminal TRM also decreases. Therefore, the output current I flowing through the output voltage Vout
out decreases, and under this reduced current setting,
The constant current control by the zero variable constant current control circuit 6 continues.
In this case, the output current Iout can be variably controlled to about zero ampere by operating the variable resistor 22. On the contrary, when the variable resistor 22 is operated to increase the reference voltage applied to the input terminal of the error amplifier 24, the output current Iout also increases, but when the command voltage from the error amplifier 24 exceeds a certain voltage level, Output voltage variable terminal TRM by diode 26
Inflow of current to the side is blocked, and an unlimited increase of the output current Iout is prevented.

As described above, according to the present embodiment, in accordance with claim 1, the stabilized DC power supply 1 having the output voltage variable terminal TRM for varying the set value of the output voltage Vout and the variable resistors 8 and 22 are provided. The zero variable control module 4 supplies a command voltage that can be changed by operation. That is,
If the stabilized DC power supply 1 having at least the output voltage variable terminal TRM is provided, it is easy to design the zero variable control module 4 forming a part of the device without designing the entire device exclusively as in the conventional case. Further, it is possible to inexpensively produce a power supply device having a zero variable constant voltage or zero variable constant current function.

According to the second aspect, the output voltage Vout from the DC stabilized power supply 1 is applied to the zero variable control module 4.
Is provided with a zero variable constant voltage control circuit 5 for maintaining a predetermined set value, a simple and inexpensive zero variable constant voltage mechanism can be provided by simply adding the zero variable constant voltage control circuit 5 to the existing DC stabilized power supply 1. A power supply having Further, according to claim 3, the zero variable control module 4 is provided with the zero variable constant current control circuit 6 for keeping the output current Iout from the stabilized direct current power supply 1 at a predetermined set value. By simply adding the control circuit 6 to the existing DC stabilized power supply 1, it is possible to create a simple and inexpensive power supply device having a zero variable constant current mechanism. Particularly in the case of the present embodiment, the zero variable control module 4 includes both the zero variable constant voltage control circuit 5 and the zero variable constant current control circuit 6,
It is possible to easily and inexpensively create a power supply device having a zero variable constant voltage and a zero variable constant current function at the same time.

Further, in this embodiment, in accordance with claim 4,
The voltage detection circuit 7 in which the zero variable constant voltage control circuit 5 detects the output voltage Vout, the first reference voltage supply circuit 9 whose setting value can be changed by the variable resistor 8, the detection signal of the voltage detection circuit 7, and the The first error amplifier 10 compares the reference voltage of the first reference voltage supply circuit 9 with the reference voltage and supplies the comparison result to the output voltage variable terminal TRM as a command voltage. It becomes possible to perform zero variable constant voltage control for the stabilized DC power supply 1. Further, in the present embodiment, according to claim 5, the zero variable constant current control circuit 6 detects the output current Iout of the stabilized DC power supply 1 by a shunt resistor 21 which is a current detector and a variable resistor 22 to set the set value. Second reference voltage supply circuit 23 capable of changing
And a second error amplifier 24 which compares the detection signal of the shunt resistor 21 with the reference voltage of the second reference voltage supply circuit 23 and supplies the comparison result as a command voltage to the output voltage variable terminal TRM. With a simple circuit configuration, it is possible to perform zero variable constant current control on the existing DC stabilized power supply 1.

The following points can be mentioned as effects of the embodiment. In the zero variable constant voltage control circuit 5, the output voltage Vout rises indefinitely when the variable resistor 8 is operated only by inserting and connecting the diode 15 for preventing overvoltage to the output terminal of the error amplifier 10 and the output voltage variable terminal TRM. This can be easily prevented on the zero variable control module 4 side. In the zero variable constant current control circuit 6, the error amplifier is simply
By simply inserting and connecting the diode 27 for preventing the overcurrent to the output terminal of 24 and the output voltage variable terminal TRM, it is possible to easily increase the output current Iout without limit at the time of operating the variable resistor 22 on the zero variable control module 4 side. Can be prevented.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

[0023]

According to the first aspect of the present invention, the power supply device according to claim 1 supplies a stabilized direct current power source having an output voltage variable terminal for varying the set value of the DC output voltage and a variable command voltage to the output voltage variable terminal. It is possible to provide a power supply device having a zero variable constant voltage or zero variable constant current function simply and inexpensively.

According to a second aspect of the present invention, in the zero variable control module, the zero variable control module includes a zero variable constant voltage control circuit for maintaining the output voltage from the DC stabilized power source at a predetermined set value. A power supply device having a zero variable constant voltage or zero variable constant current function can be provided easily and inexpensively.

According to a third aspect of the present invention, in the zero variable control module, the zero variable control module includes a zero variable constant current control circuit that maintains the output current from the DC stabilized power source at a predetermined set value. Thus, it is possible to provide a power supply device capable of easily and inexpensively producing a zero variable constant voltage or zero variable constant current function. In this case, if both the zero variable constant current control circuit and the zero variable constant voltage control circuit are provided, it is possible to easily and inexpensively provide a power supply device having the zero variable constant voltage and zero variable constant current functions at the same time.

In the power supply device according to the present invention, the zero variable constant voltage control circuit can change the set value by a voltage detection circuit that detects the output voltage of the DC stabilized power supply and a variable resistor. A first reference voltage supply circuit, a detection signal of the voltage detection circuit and a reference voltage of the first reference voltage supply circuit are compared, and the comparison result is supplied to the output voltage variable terminal as a command voltage. It is possible to provide a power supply device capable of performing zero variable constant voltage control for a stabilized DC power supply with a simple circuit configuration.

Further, in the power supply device according to a fifth aspect of the present invention, the zero variable constant current control circuit can change the set value by a current detector for detecting the output current of the DC stabilized power supply and a variable resistor. A second reference voltage supply circuit, a detection signal of the current detector and a reference voltage of the second reference voltage supply circuit are compared, and the comparison result is supplied to the output voltage variable terminal as a command voltage. It is possible to provide a power supply device capable of performing zero variable constant current control on a stabilized DC power supply with a simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention.

[Explanation of symbols]

 1 DC stabilized power supply 4 Zero variable control module 5 Zero variable constant voltage control circuit 6 Zero variable constant current control circuit 7 Voltage detection circuit 8 First variable resistor 9 First reference voltage supply circuit 10 First error amplifier 21 Shunt Resistance (current detector) 22 Second variable resistance 23 Second reference voltage supply circuit 24 Second error amplifier TRM Output voltage variable terminal

Claims (5)

[Claims] 1. A stabilized DC power supply having an output voltage variable terminal for varying a set value of a DC output voltage, and a zero variable control module for supplying a variable command voltage to the output voltage variable terminal. Characteristic power supply device. 2. The power supply device according to claim 1, wherein the zero variable control module includes a zero variable constant voltage control circuit that keeps the output voltage from the DC stabilized power supply at a predetermined set value. . 3. The zero variable control module according to claim 1, further comprising a zero variable constant current control circuit that keeps an output current from the DC stabilized power supply at a predetermined set value. Power supply. 4. The zero variable constant voltage control circuit, a voltage detection circuit for detecting an output voltage of the DC stabilized power supply,
A first reference voltage supply circuit whose setting value can be changed by a variable resistor, a detection signal of the voltage detection circuit, and the first reference voltage supply circuit.
3. The power supply device according to claim 2, further comprising: a first error amplifier that compares the reference voltage of the reference voltage supply circuit with the reference voltage and supplies the comparison result to the output voltage variable terminal as a command voltage. 5. The zero variable constant current control circuit includes a current detector that detects an output current of the DC stabilized power supply, and a second reference voltage supply circuit that can change its set value by a second variable resistor. And a second error amplifier that compares the detection signal of the current detector with the reference voltage of the second reference voltage supply circuit and supplies the comparison result as a command voltage to the output voltage variable terminal. The power supply device according to claim 3, wherein: