JPS61294769A - Stand-alone power source unit - Google Patents

Abstract

PURPOSE:To semipermanently supply good quality electric power by combining a photo power generating element with a secondary battery, and arranging a voltage stabilizing circuit in a power output part. CONSTITUTION:A power source 10 consists of an amorphous solar cell 1, a secondary battery such as a thin film type lithium battery 2, and a diode 3 for preventing opposite current flow. A positive terminal 11a of the power source 10 is connected to an output terminal 6a through a resistor 4, and a negative terminal 11b is connected to an output terminal 6b. A voltage stabilizing device 5 is inserted between output terminals 6a and 6b. The voltage stabilizing device 5 and the resistor 4 comprises a voltage stabilizing circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an independent power supply unit used in portable electrical equipment and the like.

[Conventional technology]

BACKGROUND ART In portable electrical devices, such as portable radios, or measuring devices installed on the high potential side of devices to which high voltage is applied, an independent power source such as a dry battery or a secondary battery is used.

[The 3° problem that the invention attempts to solve] This dry battery and 2
As is well known, batteries lose their function as a power source once the stored energy is consumed.
In the case of secondary batteries, it is necessary to charge them from a separate power source while they are built into the electrical equipment or removed from the electrical equipment.
Aspect 1: It is also necessary to check the state of remaining energy.
There was an f1 aspect to it.

This invention was made to solve the above-mentioned conventional problems, and aims to provide an independent power supply unit that does not require maintenance such as battery replacement and charging.

[Means to solve the problem]

In order to achieve the above object, the present invention connects a photovoltaic element and a secondary battery in parallel via a reverse current blocking diode, and provides a power supply stabilizing circuit at the output section.

[Effect]

In this invention, a rechargeable secondary battery supplies power to the load, but when the energy of the secondary battery is consumed, electrical energy is replenished by the photovoltaic element, so the battery function of the secondary battery is lost. It can be used for a long time without being damaged.

〔Example〕

FIG. 1 shows a circuit diagram of an embodiment of the present invention. In the figure, 1 is a thin film type solar power generation element, for example, an amorphous solar power generation element, 2 is a rechargeable secondary battery, for example, a thin film type lithium battery, and 3 is a backflow blocking diode. The power supply unit 10 is configured by:

The positive terminal 11a of the power supply unit 10 is connected to the output terminal 6a via the resistor 4, and the negative output terminal 11b is connected to the output terminal 11.
b, and a constant voltage element 5 is connected between both output terminals 6a and 6b.
is inserted. The constant voltage blocking 5 and the resistor 4 constitute a voltage stabilizing circuit section.

Next, the operation of this circuit will be explained.

The terminal voltage v2 of the secondary battery 2 becomes the maximum voltage V2M due to charging.
When the voltage at the terminal rises to ■ and starts supplying power to the load,
2 decreases, and when it decreases to a certain level (approximately 1/2 of the voltage V2M), the voltage suddenly decreases and the battery function is lost. is the operating range.

On the other hand, the terminal voltage VS of the solar power generation element 1 changes depending on the output current when a certain amount of light is incident, and as the current taken out to the outside increases, it decreases from the no-load voltage VSI to a constant value. When a current exceeding this amount begins to flow, it exhibits a drooping characteristic and rapidly drops. Voltage V at no load above
From SH to voltage VSL (
The operating range of the solar power generation element 1 is approximately 40% of the voltage VSH. The terminal voltage of the solar power generation element 1 is also
It changes depending on the amount of incident light, and decreases when the light becomes weaker, and when there is no sunlight, such as at night, the terminal voltage becomes O.

In the above embodiment, since the photovoltaic element 1 and the secondary battery 2 are connected in parallel, when VS > V2, the photovoltaic element 1
charges the secondary battery 2 and 1. Is the maximum terminal voltage of the power supply section 10 VS? 'l. On the other hand, when VS<V2, the presence of the diode 3 for blocking backflow prevents discharge of the secondary battery 1 toward the solar power generation element 1 side.

Now, if a load is connected between the positive and negative terminals 11a and llb of the power supply section 10, the terminal voltage of the load will be 2 from the maximum VSH.
Since the voltage varies within the range of the lowest voltage V2L of the secondary battery 2, a voltage stabilizing circuit consisting of a resistor 4 and a constant voltage element 5 is provided to stabilize the voltage.

The resistor 4 shares the potential difference ΔV between the terminal voltage of the power supply section 10 and the Zener voltage Vz of the constant voltage element 5. Output terminals 6a, 6b
The current IL flowing into the load connected therebetween maintains a constant value if the impedance of the load is constant. In this state, when the secondary battery 2 is charged by the solar power generation element 1 and the terminal voltage of the power supply section 1o increases, the current 1z flowing through the resistor 4 to the constant voltage element 5 increases, and the resistor 4
Since the voltage drop ΔV of output terminals 6a and 6b increases,
The voltage between them is maintained at a constant value Vz. On the contrary, the power supply section 10
When the terminal voltage decreases, the voltage drop Δ■ also decreases, so that the voltage between the output terminals 6a and 6b is maintained at a constant value Vz. Note that the Zener voltage Vz is the lowest voltage V of the secondary battery 2.
It is set slightly lower than 2L.

The implementation of the power supply unit according to this embodiment is, for example, a third
This is done as shown in the figure. In the figure, reference numeral 8 denotes an insulating substrate, which has printed wiring 9a and through holes 9b, and the solar power generation element 1 and the secondary battery 2 are respectively fixed to the front and back surfaces of the substrate by adhesive or other means. . The diode 3, resistor 4, constant voltage element 5, and output terminals 6a and 6b are connected to 2 of the board 8.
The secondary battery 2 is attached to the side, and as shown in FIG. 4, it is attached to a power supply case, an electric equipment case 20, etc. with the solar power generation element 1 side facing outward.

In the embodiment shown in FIG. 1, a circuit consisting of a resistor 4 and a constant voltage element 5 is used as the voltage stabilizing circuit, but as shown in FIG. 2, an IC circuit is used to control the voltage using a feedback method. By incorporating the circuit 7, more stable and high quality power can be obtained.

〔Effect of the invention〕

As explained above, this invention combines a photovoltaic element and a rechargeable secondary battery, and a voltage stabilization circuit is provided at the output section, so it is possible to supply semi-permanent, high-quality electricity. It has the advantage of not requiring the hassle of replacing and charging batteries, checking the remaining electrical energy, etc., unlike conventional products.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram of another embodiment of the invention, and FIG. and cross-sectional view,
FIG. 4 is a perspective view showing the above embodiment in use. In the figure, 1--Solar power generation element, 2--Secondary battery, 3--Reverse current blocking diode, 4--Resistor,
5--constant voltage element, 7--voltage control circuit, 8-board. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) Equipped with a power supply section formed by connecting a photovoltaic element in parallel to a rechargeable secondary battery via a reverse current blocking diode, and a voltage stabilization circuit section inserted between the power supply section and the unit output terminal. An independent power supply unit. (2) The independent power supply unit according to claim 1, wherein the secondary battery and the photovoltaic element have a thin film structure and are respectively fixed to the front and back surfaces of an insulating substrate.