JPH04172965A - Double voltage generating circuit - Google Patents

Abstract

PURPOSE:To obtain a simple and highly efficient double voltage generating circuit by connecting the intermediate point of series connected switching element with the intermediate point of series connected capacitors, connecting the opposite ends of the switching elements in parallel with a DC power supply and connecting the opposite ends of the capacitors in parallel with a load. CONSTITUTION:A DC power supply EB is connected between terminals (a), (b) and a voltage V1 is applied. When a switch element S1 is opened and a switch S2 is closed, a charging current i1 is fed to a capacitor C1 until the capacitor C1 has a voltage V1, When the switch element S1 is closed and the switch element S2 is closed, a charging current i2 is fed until the capacitor C2 has a voltage V1. When the operation is repeated, a voltage V2 which is double of a DC input voltage can be obtained across the capacitors C1, C2. Furthermore, fluctuation of DC output to a load Lo is suppressed through increase of operating frequencies of the switch elements S1, S2 and increase of capacities of the capacitors C1, C2.

Description

[Detailed description of the invention] The present invention relates to a voltage doubler generating circuit.

2. Description of the Related Art Conventionally, voltage doubler generating circuits consisting of a DC power supply, an inverter circuit, and a voltage doubler rectifier circuit have been known.

FIG. 1 is an example of a conventional voltage doubler generating circuit. In the figure, 1.2 is a DC input terminal, c, d are DC output terminals, Sl,
S2, S3, and S4 are switching elements such as thyristors and transistors, Dl and D2 are diodes, CI and C2 are voltage doubler capacitors, Ell is a DC power supply, and Ro is a load of the voltage doubler generating circuit.

When DC power source E is connected to input 1.2 and 1 is applied, Sl and 34 are closed and S2 and S3 are open, E,
Electrify in the order of 10 → S1 → D1 → C1-84-E, -, and C
Charge 1 to ■1. Next, 81, S4 is open, S2,
If S3 is a closed circuit, E, +-83 → C2 → D2 → S2
→Turn on power in the order of E4 and - to charge =I capacitor C2 to ■1. Thereafter, by repeating this operation, the capacitance of capacitors C1 and C2 becomes sufficiently large, and diode D1.
If the voltage drop of D2 is ignored, the voltage across the series circuit of C1 and C2 is V. becomes 2V, and becomes a voltage doubler generating circuit. As described above, the voltage doubler generating circuit shown in FIG. 1 requires at least four switching elements, and the structure including the control circuit for the switching elements is complicated and expensive. Furthermore, when obtaining a quadrupled voltage or the like by cascade connection, there is a drawback that an inverter circuit is required for each stage.

The present invention aims to eliminate the drawbacks of the conventional circuits mentioned above and provide a simple and highly efficient voltage doubler generating circuit, and also to be applicable to high voltage circuits and AC conversion circuits. The present invention provides a voltage doubler generating circuit that performs the following steps. FIG. 2 shows an embodiment of the present invention, and FIG. 5 is an explanatory diagram of the operation of FIG. 2. In both figures, E8 is a DC power supply, a, b are DC input terminals, c,
cl is a DC output terminal, DI D2 is a rectifier diode,
Ci, C2 are capacitors, Sl, S2 are thyristors,
Switch elements such as transistors and RO are loads.

That is, the switch elements S1 and 82 are connected in series, and both ends thereof (referred to as first ends) are connected to DC input terminals a and b. Also, capacitors C] and 02 are connected in series, and both ends (referred to as second ends) are connected to DC output terminals c and d.
Connect to. Furthermore, between the first and second ends,
Respectively, the rectifier diodes D1 and D2 are E R+ -1
C4D 1-+ C-+ R.

→d-D2-b+EI]- in the direction of energization, and the midpoint between switch elements S1 and 82 and capacitors C1 and 02
Connect between the intermediate points.

Next, the operation will be explained. DC power supply ER is connected to terminals a and b in Fig. 2, vl is applied, Sl is open, and S2
If is a closed circuit, as shown in mode I in Fig. 3(a),
The charging current 11 to C1 flows until the voltage of 01 becomes ■1. Next, when Sl is closed and S2 is opened in FIG. 2, charging current 12 flows and 02 is charged up to Vl, as shown in mode H in FIG. 3(b). Thereafter, by repeating this operation, a voltage V2 twice the DC input voltage is obtained at both ends of the second capacitors C1 and C2 connected in series. The DC output to the load R6 has less fluctuation due to an increase in the operating frequency of the switching elements S1 and S2 and an increase in the capacitance of the capacitors C1 and C2.

FIG. 4 shows an example in which the voltage doubler generating circuit of the present invention is applied to an inverter circuit. When the DC power source E6 is a battery, it is possible to easily boost the voltage, and the output voltage 2, which is boosted to twice the DC input voltage, is transferred to the switch elements S3, S4, S5,
For example, it is applied to a bridge inverter circuit configured by S6 to output AC. can be obtained.

FIG. 5 shows an example in which two stages of voltage doubler generating circuits according to the present invention are connected in cascade. As a result, the output voltage V3 becomes the capacitor C
1, C2, C3, and C4 are sufficiently large, and D 1 and D
2. D3. D4. S1, S2, S3. If the voltage drop of S4 is ignored, four times the DC input voltage ■1 can be obtained. Furthermore, if the number of stages is increased, an output voltage 2n times higher can be obtained when there are n stages.

The embodiments of the present invention shown in FIGS. 2, 4, and 5 may be used in
Various modifications can be made.

For example, when the DC power supply EB is obtained by converting the AC power supply with a rectifier instead of a battery, when an inverter circuit other than a bridge inverter is used, when the number of cascade stages is increased, when various protection devices are added, and in other cases, the design The above changes, additions, etc. are included in the present application within the scope of the gist of the present invention.

According to the present invention, since it is possible to boost the voltage of a DC power source such as a battery with a very simple circuit and high efficiency, it is effective for DC input of an inverter circuit, and has great industrial effects.

[Brief explanation of the drawing]

Fig. 1 is an example of a conventional IJ circuit, Fig. 2 is a circuit diagram showing an embodiment of the present invention, Fig. 3 is an explanatory diagram of the operation of Fig. 2, and Figs. 4 and 5 are other embodiments of the present invention. This is a circuit diagram showing Sl.
, S2, S3, S4. S5. S6 is a switch element, C1
, C2, C3, C4 are capacitors, DI, D2, D3,
D4 is a rectifier diode, EB is a DC power supply, Ro is a load,
V 1 , V 2 , V 3 , Vo are each specified voltage, a
, b, c, d, e, f, and 3.4 are designated terminals. Patent applicant: Shindengen Kogyo Co., Ltd. 2
I! Figure 1 Tail Figure 2 a Dl Figure 3 Figure 4 Figure 5

Claims (3)

[Claims] (1) A DC power supply, a series-connected switch element, a series-connected capacitor, and each rectifier diode connected between the first end of the series-connected switch element and the second end of the series-connected capacitor. The intermediate point of the series-connected switch elements and the intermediate point of the series-connected capacitor are connected, and the first both ends are connected in parallel to the DC power supply side, and the second both ends are connected in parallel to the load side. A voltage doubler generating circuit characterized in that the connection of the rectifier diode is made to be in the direction of conduction of the load current, and the switch elements connected in series are alternately turned on and off. (2) The voltage doubler generating circuit according to claim (1), which is connected in series in multiple stages. (3) The voltage doubler generating circuit according to claim (1) or (2), which additionally connects an inverter circuit.