JPS6126465A - Power source circuit - Google Patents

Abstract

PURPOSE:To generate a direct current of the polarity or voltage different from a sole DC power source by a small-size and light-weight circuit by associating a switch circuit, and a rectifier having the first and second diodes and the first and second capacitors. CONSTITUTION:A DC of a voltage V1 with respect to a ground line is applied to a terminal 11 of a switch circuit 1, and a terminal 10 is connected to the ground line. The circuit 1 alternately connects a terminal 12 with a terminal 11 in response to a switching signal of a pulse train of the prescribed period. The terminal 12 is connected with one end of a capacitor C1 of the input terminal side of a rectifier 2. The rectifier 2 has capacitors C1, C2 and diodes D1, D2, and a voltage V2 is applied to the terminal 20 of the anode side of the diode D1. The voltage of the sum or difference of the absolute values of the voltages V1, V2 is obtained from the output terminal 21. When the voltage V2 is set to zero, the negative voltage V1 can be converted to a positive voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply circuit, and more particularly to a power supply circuit that generates direct current of different polarity or voltage from a single direct current power supply.

Conventionally, a switching regulator has been used as a power supply circuit that generates direct current of a different polarity or voltage from a power source that generates a single direct current of a predetermined polarity and voltage with respect to a ground line. However, switching regulators are not only used as switch circuits and rectifier circuits, but also as voltage converters.

Since it is equipped with a transformer for insulation and insulation, it has the drawbacks of large external dimensions, large weight, and high price.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and provide a power supply circuit that is smaller, lighter, and less expensive than conventional circuits.

The circuit of the present invention includes: a switch circuit that alternately switches a predetermined first DC voltage and a voltage applied from a predetermined point of the circuit to a first terminal in response to a switching signal; and a predetermined second DC voltage. a first diode having one end connected to a second terminal which is given an output voltage, and a second diode connected in series to the first diode, between the second terminal and a third terminal for transmitting an output voltage. a diode path consisting of at least two diodes connected in series with the same polarity, and a first terminal having one end connected to the connection point of the first and second diodes and the other end connected to the first terminal.
and a second capacitor having one end connected to one end of the second diode near the third terminal and the other end connected to a ground line. ing.

Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a circuit diagram showing a first embodiment of the present invention. A direct current of voltage 1 is applied to the terminal 11 of the switch circuit 1 with respect to the ground line, and the terminal 10 is connected to the ground line. Switch circuit 1 connects terminal 12 to terminals 10 and 11 in response to a switching signal that is a pulse train of a predetermined period.
Connect alternately. The terminal 12 is connected to one end of a capacitor C1 on the input end side of the rectifier circuit 2. To the terminal 20, which is the other input terminal of the rectifier circuit 2, a DC voltage of voltage 2 is applied to the ground wire (voltage 2 may be zero < 5, in this case, the terminal 20 is connected to the ground wire). ). A diode D8 is connected in the forward direction from the terminal 20 toward the other end of the capacitor C1, and a diode D is connected in the forward direction from the connection point of the capacitor C1 and the diode DI toward the terminal 21, which is the output end. ing.

Further, a capacitor C8 is connected between one end of the output end of the diode D and the ground line.

Note that the 1% resistor p connected in parallel to the diode DI shown by the broken line is necessary only when V>o and V2<O, and is used to bypass the off-state diode D1 and allow the charging current to flow through the capacitor C1. It is connected to. (Note that the product of the values of the resistor Rp and the capacitor C1, that is, the time constant, is set to be sufficiently large.) From the switch circuit 1 to the terminal 12 according to the switching signal
, voltage ■, and voltage zero are applied alternately. If the polarity of the voltage v1 is positive, the capacitor C1 is charged when the voltage at the terminal 12 is zero, and the capacitor C2 is charged when the voltage at the terminal 12 is -. If the polarity of the voltage (2) is negative and the voltage V is higher than the voltage v1, the capacitor C1 is charged when the terminal 12 is at the voltage (2), and the capacitor C2 is charged when the voltage at the terminal 12 is zero. (The explanation will be given while ignoring the voltage drop in the switch circuit 1 and the diode D1.) First, the operation when the polarity of the voltage (2) is positive will be explained. ■,
If the polarity of is positive (or negative and V, +V>O holds), the diode D is in the on state when the voltage at the terminal 12 is zero (or the diode D is in the on state, but , through the resistive island) is applied to the capacitor (C1) and charged, and the voltage across the capacitor C1 rises substantially to the voltage V. At this time, as will be described later, the voltage of the capacitor C3 during operation increases. Since the voltage across it is higher than the voltage V, the diode D2F1
It is on. After this, when the voltage at the terminal 12 becomes V, the voltage at the connection point between the capacitor C1 and the diode D1 rises to (Ml '' Vl ), and the diode D8 turns off.
Since the voltage across the terminal 7 is discharged by the amount of current supplied to the load, it is lower than (V, ±Vt), and the diode D is turned on.

Concomitantly, capacitor C1 is recharged and the voltage across it rises to approximately (Vt above Vt).

That is, when the polarity of the voltage v1 is positive, a positive voltage of +i (Vt above Vt) is output to the terminal 21.

Next, when the polarity of voltage (1) is negative and higher than voltage V or voltage vl, when terminal 12 is at voltage vI, diode D1 is turned on, capacitor C8 is charged, and the voltage between its ends is The voltage rises to (Vl-Vl).

At this time, diode D! is in the off state. After this, when the voltage at terminal 12 becomes zero, diode D,
turns off, diode D turns on, charge is transferred from capacitor C8 to capacitor C9, and the voltage across capacitor C2 becomes approximately ('*-V
t). That is, in this case, a voltage of approximately (V'5-Vl) is output to the terminal 21.

Therefore, in the circuit of this embodiment, a new power source is obtained which has positive polarity and has an output voltage that is the sum or difference of the insulation values of voltages V and (2). Furthermore, by setting the voltage V to zero, the negative voltage V□ can be converted to a positive voltage 1v,1.

In order to realize the switch circuit 1, which is a changeover switch that alternately connects the terminals lO and 11 to the terminal 12, with an on/off switch using a transistor, the terminal 11
A first switch that turns on and off between terminals 10 and 12, and a second switch that turns on and off between terminals 10 and 12 must be combined. In this case, in order to prevent excessive current from flowing through the switch circuit 1, it is necessary to configure the first and second switches so that they are not turned on at the same time.

FIG. 2 is a circuit diagram showing an example of the configuration of the switch circuit l. Terminal 13, which is the receiving end of the switching signal, is connected to a resistor R.
1 and R1 to the ground line, and the dynamic resistance is connected to the transistor Q.

The base of t is connected. The emitter and collector of transistor Q are connected to the ground line and terminal 14, respectively.
It is connected to Terminal 1 with positive polarity voltage + voltage applied
1 is connected to the emitter of transistor Q2, which is the first switch, and is further connected to terminal 14 via resistors R8 and R4.

The base of transistor Q2 is connected to the resistor and the connection point of R4, and the collector is connected to the resistor. 1 to the ground line through the transistor Q, and the second switch is the transistor Q.
, which is connected to the base of ℃. The emitter of transistor Q is connected to terminal 12 and the collector is connected to terminal 10. Furthermore, a diode D (7i: diode D) is connected in the P direction (from the base to the emitter of the transistor Q3).The terminal 1 () is connected to the ground. This is a switch that turns on and off between the terminal 14 and the ground line according to the switching signal.In other words, when the voltage of the switching signal reaches a high level σ-■, the emitter of the transistor Q
When the voltage between the collector and the collector becomes on and the voltage of the switching signal becomes similar (σ), the emitter-collector of the transistor Q1 becomes off. When the terminal 14 and the connected terminal/line ';ll-men state is reached, the voltage between the emitter and base of the transistor Q2 increases, the base current increases accordingly, and the emitter/collector m] turns on. Become. At this time, the voltage at the collector of the transistor Q2 is different from the voltage at the terminal 12, as is clear from the above explanation when a positive voltage force is applied to the terminal 11 in FIG.
voltage will be higher than that of Therefore, diode D. turns on, and the voltage +E1 is guided to the terminal 12 via the main transistor Q2 and the diode D0. At the same time, the emitter and base of the transistor Q3 are reverse biased and the terminal turns off. The period between 10 and 12 is turned off. That is, when the connection between the terminal 14 and the ground wire is turned on, the switch of the rudder 1 is turned on, and the second switch is turned off.

Next, when the terminal 14 and the ground line are turned on, the voltage between the emitter and base of the transistor Q1 becomes almost zero, and the transistor Q1 is turned on.

Along with this, the base of transistor Q (resistance)
is grounded through the transistor Q,
Since the emitter voltage of , that is, the voltage at terminal 12 is positive, diode D0 is turned on, and transistor Q is biased and turned on. That is, when the terminal 14 and the ground wire are turned off, the first switch is turned off, and the second switch is turned on.

In this way, in the switch 1 path in the VC1iI'J2 diagram, the supply 1
When the second switch turns on (or off), the second switch turns off (or on),
Both switches are configured so that they are not turned on at the same time. Note that the transistor Q is a switch provided as a buffer so that a switching signal supply source can be connected regardless of its circuit type. When connecting the supply source, the switch can be omitted and the terminal 14V (connected).Also, it is easy to change the terminal 11 to apply a negative polarity voltage, for example, the transistors Qt and Q8. If the polarity of the diode D0 is reversed, the configuration 1 can be achieved. Figure 3 shows the configuration 2 of the present invention.
It is a circuit diagram showing an example of. This embodiment is a circuit using a rectifier circuit 3 in which the polarities of the diodes D1 and D of the first embodiment (see FIG. 1) are reversed and connected.

First, if the polarity of the voltage V applied to the terminal 11 is negative (or 2 such that the polarity of the voltage V applied to the terminal 30 is negative (or h is positive and ■□+■2<0 holds) In this case, diode D is in the on state when terminal 12 has zero voltage (or diode D is in the off state but resistor R
p), capacitor C1 is charged and the voltage across it is approximately ■.

become. When the voltage at terminal 12 becomes , after , diode D1 turns off and diode D
, turns on, the capacitors are charged, and the voltage across them becomes approximately (V, +V,). That is,
A negative voltage of approximately (V1+Vt) is output to the terminal 31.

If the polarity of the voltage ■ is positive and the voltage ■ is lower than the voltage ■1, when the voltage at the terminal 12 becomes voltage ■1, the diode DI turns on and the diode D turns off, and the capacitor C0 is charged and the voltage across it becomes approximately (Vx-Vt). After this, when the voltage at terminal 12 becomes zero, diode D is turned off, diode D is turned on, and capacitor C1
is charged and the voltage across it becomes approximately (Vs-Vt). That is, a voltage of approximately (Vs-Vs) is output to the terminal 31.

Therefore, in the circuit of this embodiment, a new power source having a negative polarity and an output voltage □ that is the sum or difference of the absolute values of the voltages V% and □, respectively, can be obtained. Furthermore, by setting the voltage V to zero, the positive voltage (1) can be converted to a negative voltage -V.

FIG. 4 is a circuit diagram showing a third embodiment of the present invention. A direct current of positive voltage +E is applied to the terminal 11 of the switch circuit 1, and the terminal 10 is connected to the terminal 41 which is the output end of the rectifier circuit 4. The terminal 12 is connected to one end of a capacitor C1 on the input end side of the rectifier circuit 4. II force direction diode D from the ground wire towards the other end of capacitor C1
1 is connected, capacitor C3 and diode D1
The connection point with the terminal 41 is connected to the terminal 41 via the diode D and the diode D. Also, the diode D2 and
A capacitor C1 is connected between the connection point and the ground line. In this embodiment, the capacitance values of capacitors C1 and C3 are selected to be substantially equal.

When voltage +E is applied to terminal 12 in response to the switching signal, diodes D2 and Ds are turned on, and diodes D and Ds are turned off, and capacitors C0 and C1 are charged and a voltage is applied between their respective terminals. The voltage becomes approximately B/2. Next, when terminal 12 is connected to terminal 10, diodes D and D are turned on and diode D is turned off, and capacitors C3 and C! are connected between terminal 41 and the ground line. are connected in parallel. Therefore, in this embodiment, the voltage +E
This results in a power supply with an output voltage approximately half that of .

Note that when applying a negative voltage or -E to the terminal 11 instead of the voltage +E, the diode D of the rectifier circuit 4 is used.

A power supply with a voltage of -E/2 can be obtained by using a rectifier circuit in which all of the polarities of the first and second sides are reversed and connected.

By appropriately combining the circuits of the first to third embodiments as described above, a DC power source having a different polarity or voltage can be obtained from a single power source. That is, first, as described above, the polarity of the voltage of a single power source can be inverted using the circuit of the first or second embodiment. Also,
In the circuit of the first or second embodiment, the voltage of a single power supply is applied to the switch circuit 1 and the rectifier circuit 2 or 3 as voltages V and V, and the voltage of the single power supply is approximately twice that of the voltage of the single power supply. Can generate voltage. Therefore, the first to third
The circuit of the embodiment provides a power supply with double or half the voltage of a single power supply. In this way, a plurality of voltages are generated based on a single power source, and two of the voltages are further combined as appropriate to generate a voltage that is the sum or difference of both voltages in the circuits of the first and second embodiments. As a result, a DC power source having a polarity or voltage different from that of the original single power source is obtained.

When setting a plurality of such combinations of voltages, if the voltages (■1) input to the switch circuits l of the circuits of the first or fourth second embodiments used in each combination are all the same, the switch circuits 1 Compared to using only one circuit and connecting the input terminals of a plurality of rectifier circuits 2, 3, or 4 to it and providing a switch circuit 1 for each combination, the number of switching times is M.
The number of l can be reduced, and the circuit can be made smaller.

An example is shown below.

FIG. 5 is a block diagram showing a configuration example of a combination of the first and second embodiments. Terminal 12 has the input terminals of rectifier ports [2 and 3 connected in parallel, and terminal 11 has a positive 9
A positive voltage +E is applied to the terminals 20 and 30.

However, 5 t E B+ and E2 are set so that El>F'2 is satisfied. W. As explained in FIGS. 1 and 83, a positive voltage (E1+Fy) is output to the terminal 21, and a negative voltage -(Et-Ex) is output to the terminal 31.

As is clear from the embodiments described above, the circuit of the present invention eliminates the need for large size, heavy, and expensive transformers, and allows direct current of different polarity or voltage to be generated from a single power supply. This has the effect of realizing a power source that is smaller, lighter, and cheaper than conventional ones.

[Brief explanation of drawings]

Each of FIGS. 1 to 4 is a circuit diagram showing an embodiment of the present invention, and FIG. 5 is a block diagram showing an embodiment of the present invention. 1... Switch circuit, 2-4... Rectifier circuit, 10-14, 20.21.30,31,41...
...Terminal, c, *ct...Capacitor, D
0~D8...Diode, Q+~Q3...
...transistor, mol.....resistance 1, \, 1 V2 Fig. 1 Fig. 3

Claims (5)

[Claims] (1) A switch circuit that alternately switches a predetermined first DC voltage and a voltage applied from a predetermined point of the circuit to a first terminal in response to a switching signal, and a switch circuit that is applied with a predetermined second DC voltage. A first terminal with one end connected to a second terminal.
and a second diode connected in series with the first diode.
a diode path consisting of at least two diodes connected in series with the same polarity between the second terminal and a third terminal delivering the output voltage;
a first capacitor with one end connected to the connection point of the first and second diodes and the other end connected to the first terminal; and one end connected to the third terminal of the second diode. and a second capacitor connected to one end and a second capacitor connected to a ground line at the other end. (2) The switch circuit includes a first transistor that turns on and off the first DC voltage to the first terminal in response to the switching signal, and a first transistor that turns on and off the first transistor. The power supply circuit according to claim 1, further comprising a second transistor that turns off and turns on a voltage applied from a predetermined portion of the circuit to the first terminal, respectively. (3) The switch circuit alternately switches the first DC voltage and the voltage applied from the ground line to
2. The power supply circuit according to claim 1, wherein the diode path of the rectifier circuit comprises two diodes, the first and second diodes. (4) The switch circuit alternately switches the first DC voltage and the voltage applied from the third terminal and guides it to the first terminal, and the diode path of the rectifier circuit is connected to the first DC voltage and the voltage applied from the third terminal. and a third diode further connected in series with both, the capacitance values of the first and second capacitors are set equal to each other, and the second terminal is connected to the ground. The power supply circuit according to claim (1), which is connected to a power line. (5) The power supply circuit according to claim (1), wherein a bypass resistor is connected in parallel to both ends of the first diode of the diode path.