JPS62178173A - Power unit - Google Patents

Abstract

PURPOSE:To use a regulator having the same constitution by changing over a rectifying means to full-wave rectifying operation or voltage-doubler rectifying operation in response to a reaching to a predetermined value or less of input AC voltage. CONSTITUTION:When commercial AC voltage is applied between terminals 1, 2 and switches 4, 5 are closed, the voltage is rectified by a diode bridge 6 while being rectified by a diode D0. Rectified voltage by the diode D0 is divided by resistors R1, R2, and applied to an anode for a Zener diode ZD, switching operation corresponding to a voltage value is conducted, and a transistor Q1 is turned ON/OFF. Accordingly, a TRIAC is turned ON/OFF, and the rectifying operation, full-wave rectifying operation and voltage-doubler rectifying operation, of the diode bridge 6 is changed over.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a power supply device used for equipment such as a television receiver, and more particularly to a power supply device that can be used in two regions with different commercial AC voltages. .

B0 Summary of the Invention The present invention detects an input AC voltage in a power supply device that is used in equipment such as a television receiver and is compatible with two areas with different commercial AC voltages, and By switching between full-wave rectification operation and voltage doubler rectification operation accordingly, it is possible to eliminate the problems of conventional power supply bags, which have a configuration in which the rectification operation is manually switched using a switch, and also to make the regulator common. This makes it possible to reduce the size, simplification, and cost.

C6 Prior Art In general, the total field is called a low voltage region, which is below region C where the commercial AC voltage is 100 to 120 V, which is adopted in Japan, the United States, etc. ) and areas where commercial AC voltages of 220 to 240V are used in Europe (hereinafter referred to as high voltage areas). These two
When manufacturing equipment such as television receivers that are compatible with different regions, the following methods have conventionally been used to deal with power supplies with regulators (stabilizing circuits) used in the equipment. It's here.

(a) Design dedicated regulators for each and treat them as separate equipment.

(11) Make the regulator a so-called wide range regulator that can be used throughout the company.

(C) Install a switch in a certain part of the equipment and manually switch between full-wave rectification and voltage doubler rectification.

Problems to be Solved by the D0 Invention However, in the case of (a) above, there was a problem in terms of management man-hours. Further, in the case of (b) above, there are problems such as an increase in the size of the regulator and an increase in cost. Also,
The above case (C) has the advantage of being able to use a common regulator, but it also has the problems of causing damage to the circuit due to incorrect switching of the switch and making the switching operation of the switch cumbersome.

Therefore, the present invention has been proposed in view of the above-mentioned conventional heating point, and the rectifying operation is automatically switched according to the input AC voltage, and the regulators are shared, that is, regulators with the same configuration are used. The purpose is to provide a power supply device that can

Means for Solving the E0 Problem In order to achieve the above-mentioned objects, the power supply device of the present invention has the following features:
A voltage detecting means for detecting whether the input AC voltage is below a predetermined value (a); and a rectifying means for switching and selecting a full-wave rectification operation and a voltage doubler rectification operation to rectify the input AC voltage; It is characterized in that the rectifying operation of the rectifying means is switched in accordance with the detection output from the means.

Moreover, the uninvention is characterized in that the above-mentioned @Ammunition U is characterized in that the voltage detection means has a Zener diode, and rectifies the input AC voltage and supplies it to the Zener diode to obtain a detection output. .

21 Effects According to the present invention, the voltage detection means detects whether the input AC voltage is below a predetermined value, and the full-wave rectification operation and the double By switching between the voltage rectification operation and the voltage rectification operation, substantially the same DC voltage can be obtained even when used in either of two regions where commercial AC voltages are different.

G. Examples Examples of the present invention will now be described in detail with reference to the drawings.

G-1, First Embodiment FIG. 1 shows the power supply device of the first embodiment. One of the terminals 1 and 2 to which the commercial AC voltage vI is applied is connected via a fuse 3 and a switch 4, and the other is connected via a switch 5 to an input terminal of a diode bridge 6, which is a rectifier consisting of diodes D and D4. each connected. The switch 5 is a motion switch. Diode D2 of the diode bridge 6. A first anode of a triac 7, which is an AC control element, is connected to the connection point D3. A capacitor C0 and a transistor Q are connected between the first anode and the gate of this triac 7.
The emitter and collector of 1 are connected in parallel. A rectifying diode D and a resistor RIy are connected in series between the input terminals of the diode bridge 60. A capacitor C2 is connected in parallel with the resistor R1 and the resistor R2.The connection point between the resistor R1 and the resistor R2 is connected to the base of the transistor Q1 via a Zener diode (constant voltage diode) Zf) which is the main element of the voltage detection means. Also connected to the capacitor C! through the resistor C! It is connected to the. Further, capacitors C3 and C4, resistors R4 and R, and a smoothing capacitor C3 are connected in parallel between the output terminals of the diode bridge 6, and the second anode of the triac 7 is connected to the capacitors C3 and C3. , and the connection points of resistors R, ,R,.

Further, one of the output terminals of the diode bridge 6 is connected to a terminal 8, and the other output terminal is connected to a terminal 9. These terminals 8 and 9 are connected to, for example, a regulator (not shown).

Next, the operation will be explained. When a commercial AC voltage v1 is applied between the terminals 1 and 2 and the switches 4 and 5 are closed, the voltage V1 is rectified by the diode bridge 6 and also by the diode D0. Then, the voltage rectified by the diode D0 is divided by the resistors R1 and R2 and applied to the anode of the Zener diode Zf), and a switching operation is performed according to the voltage value to turn on the transistor Q. As a result, the triac 7 is turned on and off, and the rectification operation of the diode bridge 6, that is, the full-wave rectification operation and the voltage doubler rectification operation are switched. Note that the threshold voltage is set to, for example, about 150 V (alternating current), and the Zener diode ZD has a Zener voltage of about 15 V, for example.

This will be explained in detail below. 220~ in high voltage areas
When a commercial AC voltage V of 240V is applied between the terminals 1.degree.2 and the switches 4 and 5 are closed, a DC voltage of about -20V, for example, is applied to the anode of the Zener diode ZD. This voltage exceeds the Zener voltage, turning on the Zener diode ZD and turning on the transistor Q. Therefore, the triac 7 remains off, and the diode bridge 6 performs normal full-wave rectification, and a DC voltage V0 of about 300V is obtained between the terminals 8 and 9.

Further, when a commercial AC voltage Yl of 100 to 120V is applied between terminals 1 and 2 in a low voltage area and switches 4 and 5 are closed, a DC voltage of about -10V is applied to the anode of the Zener diode ZD. applied. Since this voltage does not exceed the Zener voltage, the Zener diode ZD is not turned on and the transistor Q1 is turned off. The triac 7 is off immediately after the switches 4 and 5 are closed, and full-wave rectification starts, but the capacitor C is charged through the resistor R5 and the gate is negatively biased. Citri attack 7 is turned on. The time constant at this time is determined by resistor R3 and capacitor C1.

And the diode D2yD3 of the diode bridge 6
are respectively reverse-biased by capacitors C3 and C4 to be in a cut-off state, and the diode bridge 6 performs a voltage doubler rectification operation. That is, input AC voltage v1
Diode D during the period of interplay with the positive half cycle of .

Capacitor C3 is charged through diode D4 during the period corresponding to the negative half cycle, and a DC voltage v0 of about 300V, approximately twice the peak value, is obtained between terminals 8 and 9. .

In this way, in the power supply device of the first embodiment, whether or not the input AC voltage v1 is lower than or equal to the threshold voltage (predetermined value) is detected by the Zener diode Zl), and the The rectifying operation of the diode bridge 6 is automatically switched.

Therefore, the disadvantages of the conventional power supply device in which the control #L operation is manually changed over by a switch are eliminated. That is, it is possible to prevent damage to the circuit due to incorrect switching of the switch, and it is also possible to eliminate the troublesome operation of the switch. Further, since substantially the same direct current voltage (rectified voltage) can be obtained whether the device is used in a low voltage region or a high voltage region, a regulator can be used in common, and miniaturization and simplification can be achieved. Also, with this,
Cost reduction becomes possible. Furthermore, since the rectification operation by the diode bridge 6 starts with full-wave rectification no matter where it is used, high voltage will not be rectified at voltage, and safety measures are perfect.

G-2, Second Embodiment The Dentsu equipment of the second embodiment shown in FIG. 2 is one in which the present invention is applied to a power supply device for a television receiver.
Auto degauss (automatic demagnetization) at the same time as switching the rectification operation
It is also possible to control the circuit. The emitter of transistor Q2 is connected to switch 5 and diode bridge 6.
The base is a Zener diode Z
Connected to D. Further, the collector of the transistor Q2 is connected to the coil 21 of the relay 20. One end of the degauss coil 22 is connected between the switch 4 and the diode bridge 60, and the other end is connected between the switch 5 and the diode bridge 6 via the positive temperature coefficient thermistor (posistor) 23, 24 and the contact of the relay 20. has been done. An external resistor R0 is connected to the positive temperature coefficient thermistor 24. For the positive temperature coefficient thermistors 23, 24 and the external resistor R6, resistance values are used such that the optimum demagnetizing effect can be obtained in each of the low voltage region and the high voltage region. - As an example, the positive temperature coefficient thermistors 23 and 24 have resistances of 8Ω and 30Ω at room temperature, respectively, and the external resistor R6 has a resistance of 100Ω. Note that the configuration of other parts is the same as that of the first embodiment described above, and a description thereof will be omitted.

Commercial AC voltage V of 220-240V in high voltage areas
When l is applied between terminals 1 and 2, Zener diode ZD turns on, transistor Q1 turns on, full-wave rectification is performed, and transistor Q2 turns on, causing current to flow through coil 21 of relay 20 and contact is switched, and the input voltage vi is applied to the degauss coil 22 via the positive temperature coefficient thermistor 24 and resistor R6 to perform a degaussing operation.

In addition, when a commercial AC voltage v1 of 100 to 120 V is applied between terminals 1 and 2 in a low voltage area, the Zener diode ZI) is not turned on and the transistor Q8 is turned off, and the voltage rectification operation is not performed. At the same time, the transistor Q is also turned off and the contacts of the relay 20 are not switched, and the input voltage v1 is applied to the degauss coil 22 via the positive characteristic thermistor 23 to perform the degaussing operation.

According to the power supply device of the second embodiment, the same effects as those of the first embodiment can be obtained, and the positive temperature coefficient thermistors 23 and 24 are automatically switched according to the input voltage vi. It is possible to obtain the optimum degaussing effect in both low-voltage and high-voltage areas.

It should be noted that the configuration of the autodegauss circuit shown in FIG. 2 is a theoretical one, and various configurations are actually possible.

G-3, Third Embodiment The third embodiment of the power supply device shown in 3:/I uses a relay 30 as the middle stage of voltage detection.

The triac 7 has a first anode connected to capacitors Cs and C.
The second anode is connected to the connection point of the diode D2.4 of the diode bridge 6 and the connection point of the resistor R41. It is connected to the connection point of Ds. The gate of the triac 7 is connected to a capacitor C4 via a resistor. Further, a capacitor C1 and a relay 30 are connected between the 17th node and the gate of the triac 7.
are connected in parallel. Coil 31 of the above relay 30
is connected between the input terminals of the diode bridge 6. The relay 30 is, for example, an AC relay that turns on when the applied AC voltage is 176V or higher and turns off when the applied AC voltage is 144V or lower. The configuration of other parts is as follows.
This is the same as the first embodiment described above, and the explanation will be omitted.

Commercial AC voltage of 220-240V in high voltage areas7
1 is applied between terminals 1 and 2, the relay 30 is turned on and the trial act is turned off, and the diode bridge 6
A full-wave rectification operation is performed.

Further, when a commercial AC voltage Y1 of 100 to 120 V is applied between the terminals 1 and 2 in a low voltage region, the relay 30 is not turned on. Triac 7 is switch key,
Immediately after 5 is closed, it is off and full-wave rectification starts, but the capacitor C1 is charged through the resistor R7 and the gate is negatively biased, so the citriac 7 is turned on and the diode bridge 6, a voltage rectification operation is performed.

According to the power supply device of the third embodiment, the same effects as those of the first embodiment can be obtained.

It should be noted that the present invention is of course not limited to the first to third embodiments described above, and for example, instead of the triac 7, it is also possible to use a relay or a thyristor 2 connected in antiparallel.

H0 Effects of the Invention As is clear from the description of the embodiments described above, in the power supply device of the present invention, the voltage detection means detects whether the input AC voltage is below a predetermined value, and depending on the detection result, The rectifying operation of the rectifying means is automatically switched. Therefore, it is possible to eliminate the problems of the conventional power supply device in which the rectification operation is manually changed using a switch. Further, since substantially the same DC voltage (rectified voltage) can be obtained whether the device is used in a low voltage region or a high voltage region, a common regulator can be used, and miniaturization and simplification can be achieved. Moreover, this enables cost reduction.

Furthermore, CMR installed in conventional worldwide power supply equipment,
The transformer (common mode noise transformer) has one large core in order to suppress the saturation of the transformer when the current increases.
However, according to the present invention, substantially equal rectified voltages can be obtained and a noise filter can be inserted after the rectifier circuit, so that miniaturization can be achieved.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a tube 1 of a power supply device according to the present invention, FIG. 2 is a circuit diagram also showing a second embodiment, and FIG.
The figure is also a circuit diagram showing the third embodiment. 6...Diode bridge Zf), Zener diode 30■" Relay

Claims (2)

[Claims] (1) comprising voltage detection means for detecting whether the input AC voltage is below a predetermined value; and rectification means for switching and selecting full-wave rectification operation and voltage doubler rectification operation to rectify the input AC voltage; A power supply device characterized in that the rectifying operation of the rectifying means is switched according to the detection output from the voltage detecting means. (2) The power supply according to claim 1, wherein the voltage detection means has a Zener diode, and rectifies the input AC voltage and supplies it to the Zener diode to obtain a detection output. Device.