JPS6264220A - Power source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power supply device, particularly a power supply device using a solar cell.

[Prior Art] Recently, solar cells have come to be used as a power source in low power consumption electronic devices such as electronic desktop calculators. A power supply device using a conventional solar cell is shown in Figs. 4(A) to (D).
), the solar cells 10 are fixedly connected individually or in series, parallel, or in a combination of parallel and series,
It was supposed to supply power to the

However, solar cells have a problem in that the generated voltage fluctuates due to fluctuations in conditions such as the intensity of light from a light source, temperature, or load. For example, when the intensity of the light from the light source is high, the generated voltage is high, and when the intensity of the light is low, the generated voltage is low.In order to always supply a constant voltage to the load, voltage stabilization such as a series regulator or switching regulator is required. It was necessary to install a circuit. Therefore, the device becomes complicated, which tends to increase costs, and there is a problem that power loss occurs in the stabilizing circuit itself.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a plurality of solar cells, a switch means for switching the connection between the solar cells, a means for detecting the output of the solar cells, and an output of the solar cells. A configuration is adopted in which means is provided for controlling the switch means so as to supply optimum power to the load depending on the state.

[Function] With the above configuration, the solar cell can be used efficiently according to the light intensity of the light source of the solar cell, and constant power can always be supplied to the load without power loss.

[Example] The present invention will be described in detail below based on an example shown in one drawing.

FIG. 1 is a block diagram showing an embodiment of a power supply device according to the present invention, and the illustrated power supply device has a solar cell unit 30. As shown in FIG. The solar battery cell 30 is configured such that the series connection of the solar battery subunit 60 and the diode 33, 34 is further connected in parallel, and the connection point between the diode 33, 34 and the subunit 60 can be short-circuited by a switch SW3. .

The structure of the solar cell subunit 60 is shown in the block diagram of FIG. 2.The solar cell subunit 60 is connected in the same way as the solar cell unit 30 by connecting a lower solar cell subunit 61 to a diode 63, 64 and a switch SW2. It is connected via

Furthermore, the solar cell subunit 61 is constructed as shown in FIG. That is, solar cell subunit st is constructed by connecting two solar cells SCI and SC2 via diodes Di, D2 and switch SWI in the same manner as described above. Now, considering the solar cell subunit 61 in FIG. 3, when the switch SWl is open, the generated voltage of the subunit 61 is approximately equal to the individual generated voltage of the solar cells S01 and SC2. D1. Although there is a voltage drop of D2, the generated voltage is configured to be larger than the voltage drop of the diode, and the voltage drop of the diodes Di and D2 is ignored. That is, when switch SWl is open, subunit 6I has solar cells SCI and SC2 connected in parallel.

Next, when switch SWI is closed, solar cells SCI, SC
2 are connected in series, and therefore the generated voltage of the subunit 61 is twice that of the case of parallel connection. At this time, the diode DI
, D2 are each connected in parallel with the solar cell, but each generated voltage has a polarity opposite to the rectifying direction of the diode, and the diodes D1 and D2 have no relation to the output.

As described above, the solar cell subunit/Toro 1 can switch the output voltage in two stages by operating the switch SWl. When these subunits are connected as shown in FIG. 2 to form the solar cell subunit 60, the subunits 61 can be connected in series or in parallel by operating the switch SW2. Therefore, by operating the switches SWI and SW2 in this state, it is possible to switch the 4-W solar cells included in the subunit 60 into four stages, from all parallel to all series.

Furthermore, if you connect the subunit) 60 as shown in Figure 1,
By operating the switch SW3 in addition to the switches swt and SW2, the output of the solar cell unit 30 can be changed to a total of eight levels, from a state in which all eight solar cells are connected in parallel to a state in which all eight solar cells are connected in series. Can be adjusted.

The output of the large intestine battery 30 thus obtained is supplied to the load 20 via a decoupling capacitor C. Further, the output voltage of the solar cell unit 30 is detected by a resistance unit 40 for monitoring. The resistor unit 40 consists of two resistors R1 and R2 connected in series, and this partial voltage is inputted to a control section 51 composed of a microcomputer or the like via an A/D converter.

The control section 51 constitutes a power supply control unit 50 together with an A/D converter 52 and an input/output interface 53. When the load 20 is an electronic circuit such as a calculator, the control unit 51 may be a microcomputer that controls the entire device.

The interface 53 is connected to the switch SW3 and the switches swi and S included in the solar cell subunit) 60.61.
This controls the switching operation of W2. In addition to the control by the control unit 51, this interface 53 can switch the connection of the solar cell subunits by, for example, manual input from the outside.

In the above configuration, the output voltage of the solar cell unit 30 is constantly detected by the resistance unit 40, and the control unit 5
1 takes in the output detection value of the solar cell unit 30 at a predetermined timing via an A/D converter 52, and receives the detected output value of the solar cell unit 30 via an interface 53 so as to satisfy a predetermined supply voltage to the load 20. The output of the solar cell unit 30 is controlled by controlling the connection of 8 solar cells.
Control is performed to obtain the optimum output voltage for the load 20 by switching in stages.

With the above configuration, a constant voltage can always be supplied to the load 20 even if the intensity load of the light source or the environmental temperature changes and the output of the solar cell fluctuates. Furthermore, since there is no power loss caused by a stabilizing circuit as in the conventional case, the output voltage of the solar cell can be used effectively.

Although the above embodiment shows an example in which the output voltage is kept constant, a detection resistor is connected in series with the load 20, and the voltage across this resistor is input to the A/D converter 52 to control the load current. It is also possible to configure a configuration in which the current of the load is input to the control unit 51, thereby controlling the current of the load to be constant. In addition, the control section 5 can be connected to the external control input terminal of the interface 53 or from another route.
It is also possible to input a target voltage or current to 1 to obtain a desired output. Furthermore, although the solar cell unit is configured with eight solar cells in the above example, the number of solar cells is not limited to eight, and the output voltage can be further switched in multiple stages.

Furthermore, as another embodiment, a switch SWt for switching a diode for connecting a solar cell subunit or a solar cell is used.
(or S''W2.5W3) is inserted into the circuit when it is OFF, and is disconnected from the circuit when switch SWI is turned ON, so that the voltage drop of the connecting diode can be ignored. It is possible to further improve power efficiency.

[Effect] As is clear from the above explanation, the control means and the means for detecting the output of the solar cell according to the present invention, and the connection of the solar cell so as to obtain the optimum output for the load according to the detected output. Since the structure is equipped with a switching control means, it has the advantage of being able to supply the desired power to the load even if the output of the solar cells fluctuates due to changes in conditions such as the intensity of light from the light source, the condition of the load, or the environmental temperature. power supply equipment can be supplied.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the power supply device according to the present invention, FIGS. 2 and 3 are block diagrams showing the configuration of a solar cell subunit, and FIGS. 4(A) to (D) 1 is a block diagram showing the configuration of a conventional solar battery power source. 20...Load 30...Solar cell unit 6
0.61...Solar cell subunit SCI, SC2・
...Solar cell 51...Control unit solar cell:,t! ! , Den 1 Hara no Flock 7 41! Large #5 Electric] (20,000 units, 2 tons) Figure 079 Hitogatsu Electric] Dead Gubu] 2, 2 tons of terrorism, Rl No. 31
2nd m

Claims (1)

[Claims] A plurality of solar cells, a switch means for switching the connection of the solar cells, and an output detection means for the solar cells, and the connection of the solar cells is switched according to the detected output state of the solar cells to provide the optimum power to the load. A power supply device comprising means for controlling said switch means to supply power.