JPH04165410A - Direct-current power unit - Google Patents

Abstract

PURPOSE:To stably output a voltage by varying the output voltage of a reference voltage generating circuit by detecting and amplifying variation in the input voltage through resistance division, etc. CONSTITUTION:The reference voltage generating circuit 6 is equipped with a detecting circuit part which divides a DC voltage inputted from a voltage input terminal 1 through resistances 9 and 10 to detect the input voltage variation, a voltage generating circuit part which generates a constant voltage while resistances 11 and 12 and a constant voltage diode 13 are connected in series, and an amplifying circuit part consisting of a transistor (TR) 14 for amplification and a resistance 15. In such a case, when the input DC voltage rises, the base voltage of the TR 14 rises to increase the current flowing through the resistance 11, whose voltage drops increases to reduce the voltage variation at the connection point between the resistances 11 and 12; and then the voltage supplied to the constant voltage diode 13 becomes stable and the output voltage (reference voltage Vb) of the voltage generating circuit 6 becomes stable. Consequently, the voltage generating circuit 2 can generates the stable DC voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a DC power supply device incorporated into electronic equipment and the like.

An example of the basic circuit of a conventional DC-DC converter type DC power supply device is shown in Fig. 1 (this Fig. 1 is also used in the present invention), and an example of a conventional reference voltage generation circuit in the device is shown in Fig. 3. are shown respectively. In FIG. 1, a DC voltage is input from the outside to a voltage input terminal 1 and is supplied to a voltage generation circuit 2. As shown in FIG. The voltage generation circuit 2 is a DC-DC converter type DC voltage generation circuit, which generates a DC voltage different from the DC voltage inputted from the voltage input terminal 1, and supplies it to the output terminal 3 as an output voltage. A reference voltage generation circuit that receives the voltage V obtained by dividing the output voltage of the voltage generation circuit 2 by a resistor 4.5 and the DC voltage input from the voltage input terminal 1, and generates a reference voltage using a resistor and a constant voltage diode. 6' is inputted, and a comparison detection circuit 7 that detects and amplifies the difference voltage between the input voltages v, , vb' and the output voltage of the comparison detection circuit 7 is inputted, and the output voltage is set to the above voltage. A D(, -DC converter type) with a voltage stabilizing circuit function configured with an output voltage control circuit 8 that supplies voltage to the voltage generating circuit 2 and controls the voltage generating circuit 2 so that the output voltage of the voltage generating circuit 2 is constant. A DC power supply device outputs a DC voltage to the output terminal 3.The reference voltage generating circuit 6' has a circuit configuration as shown in FIG. 3, and 17 and 13 are the resistors and constant voltage diodes. .16 is an electrolytic capacitor.

Problems to be Solved by the Invention However, the above-mentioned conventional DC with voltage stabilizing circuit function
- A problem with DC converter-type DC power supplies is that the output voltage does not sufficiently follow up with changes in the load and input voltage, and a stable voltage is not output.

The present invention solves these conventional problems and eliminates load fluctuations,
It is an object of the present invention to provide a DC power supply device whose output voltage is stable even when input voltage fluctuates.

Means for Solving the Problems In order to achieve the above object, the present invention provides a reference voltage generation circuit with a detection section that detects fluctuations in input voltage by resistor division, an amplification section that amplifies the detected voltage, and outputs a reference voltage. The reference voltage generating circuit outputs a stable output voltage by varying the output voltage of the reference voltage generating circuit with respect to fluctuations in the input voltage.

Effects With the above configuration, the present invention can stably output the output voltage of the voltage generating circuit by detecting and amplifying fluctuations in the input voltage by resistor division or the like and varying the output voltage of the reference voltage generating circuit.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a basic common circuit of the DC-DC converter type DC power supply device explained in the above-mentioned conventional technology, and FIG. 2 shows one implementation of the reference voltage generation circuit in the circuit according to the present invention. FIG. 3 is an example circuit diagram.

Furthermore, FIG. 4 is a power supply voltage (input voltage) versus reference voltage output characteristic diagram.

The configuration and operation of the circuit shown in FIG. 1 are almost the same as the configuration and operation of the conventional technology described above, and the difference is that the configuration and operation of the reference voltage generation circuit 6 are different, so that the output voltage is set to Vb. That's true.

The reference voltage generation circuit 6 according to the present invention will be explained below with reference to FIG.

In FIG. 2, a detection circuit section that divides the DC voltage input from voltage input terminal 1 by resistors 9 and 10 to detect input voltage fluctuations, and resistors 11 and 12 and a voltage regulator diode 13 are connected in series. The output voltages of the voltage generation circuit section that generates a constant voltage and the detection circuit section are input to the base of the amplifying transistor 14, the emitter is grounded by the resistor 15, and the collector is connected to the connection point of the resistors 11 and 12, and the voltage is A reference voltage generating circuit 6 is constructed by connecting an amplifier circuit section for amplifying fluctuations, and a constant voltage diode 13) and an electrolytic capacitor 16 in parallel.

Next, its operation will be explained.

(1) When the DC voltage input from the input terminal 1 becomes high, the base voltage of the amplifying transistor 14 increases, and the current flowing through the resistor 11, which is the load resistance of the amplifying transistor 14, increases, and the resistance increases. The voltage drop across resistor 11 increases and the voltage fluctuation at the connection point of resistor 11.12 decreases. Accordingly, the voltage supplied to the constant voltage diode 13 becomes stable, and the output voltage (reference voltage Vb) l of the voltage generating circuit 6 also becomes stable.

(2) When the same-power DC voltage becomes low, the base voltage of the amplifying transistor 14 becomes low, the current flowing through the resistor 11 decreases, the voltage drop across the resistor 11 decreases, and the resistor 1
1. Voltage fluctuations at the 12 connection points are reduced. Accordingly, the output voltage (reference voltage Vb) of the voltage generating circuit 6 becomes stable.

If the above explanation is illustrated in a characteristic diagram, the characteristics of the output voltage Vb of the reference voltage generation circuit 6 (as shown in FIG. 4) are as follows:
A more stable reference voltage is output than the output voltage Vb' caused by '.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the reference voltage for comparison with the output voltage generated by the voltage generation circuit is stabilized even when the input DC voltage fluctuates, so that the voltage generation circuit can It is possible to realize a DC power supply device that generates a stable output voltage.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a DC-DC converter type DC power supply device with a voltage stabilizing circuit function according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a reference voltage generation circuit according to an embodiment of the present invention, and FIG. The figure is a circuit diagram of a reference voltage generating circuit in a conventional example, and FIG. 4 is an output characteristic diagram of power supply voltage (input voltage) versus reference voltage. 1... DC voltage input terminal, 2... Voltage generation circuit, 3... DC voltage output terminal, 4,
5. ...Resistor, 6...Reference voltage generation circuit, 7...Comparison detection circuit, 8...Output voltage control circuit, 9.10, 11.12゜15・・・・・・
・Resistance, 13... Constant voltage diode, 14...
...Amplification transistor. Name of agent: Patent attorney Haruaki Ogata 2 people Figure 3 Figure 4 4tv is - 9 in 1 -

Claims (1)

[Claims] Inputs a voltage generation circuit that inputs a DC voltage to the input terminal, converts it to a different DC voltage, and outputs the DC voltage to the output terminal, and inputs a reference voltage generated by the reference voltage generation circuit and a comparison voltage obtained by dividing the above output voltage by resistance. a comparison detection circuit that detects the difference voltage and outputs a control voltage; and a comparison detection circuit that inputs the control voltage and supplies the output voltage to the voltage generation circuit so that the output voltage of the voltage generation circuit becomes a constant voltage. A DC-DC converter type DC power supply device configured with an output voltage control circuit that controls a voltage generation circuit, wherein a reference voltage that is an output voltage of the reference voltage generation circuit is detected by detecting fluctuations in the input DC voltage. A DC power supply device that outputs a constant output voltage of the voltage generating circuit by changing the output voltage.