JPH10210682A - Solar battery drive circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the power supply which extends for a long time by accumulating electric energy generated in a solar battery generator in a capacitor, consisting of a solid-state pole electric double layer battery, and also discharging it by operating a balancer, when the voltage between both poles of the capacitor drops to the specified value or under. SOLUTION: A capacitor 4, consisting of a solid-state pole electric double layer battery, is connected through a reverse flow preventive diode 3 to the output side of a solar battery generator 2 for converting solar ray into electric energy. Then, the electric energy generated in the generator 2 is accumulated in the capacitor 4, and it is discharged to the side of a load 11 in the suspension period of the electric energy from the generator 2. Here, when the voltage between both poles of the capacitor 4 drops to the specified level or below, an auxiliary secondary battery 9 is discharged by turning on a contact 7 by means of the sensor (coil) 6, incorporated into the balancer 5 connected in parallel with the capacitor 4, whereby the output voltage to a DC-DC converter 10 is kept constant, and the power supply to the load 11 is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving circuit using a solar cell.

[0002]

2. Description of the Related Art Heretofore, there has been known an apparatus which uses a storage battery to store current from a solar cell generator, thereby driving a clock or the like. In this method, a drive circuit is operated by a power storage element that can be maintained for a long time mainly by a chemical change of a cadmium storage battery, a lead storage battery, or the like.

[0003] The solar cell generator is for replenishing the current capacity of the power storage unit. In other words, the solar cell generator used here merely acts as a secondary function of backing up the power supply voltage and current of the storage battery, and extends the life of the power consumption of the main storage body. It is useful for Therefore, the power storage unit is of a consumption type, and in any case, needs to be replaced within one to two years, or within five years.

Therefore, in order to make the discharge time extremely long instead of the storage battery, the inventor of the present invention has previously published Japanese Patent Application No. 63-12150.
No. 0 (Japanese Unexamined Patent Publication No. 2-7835) was proposed, and it was planned to solve this problem by using a special electric double layer battery.

Although the technique proposed above is certainly an extremely effective method, for example, a load of 100 mA is required to be 2.
Considering continuous use for 4 hours, the charge (Q) is 24 × 60 × 60 (sec) × 0.0 at a load of 20 mA.
2 = 1728 (coulomb) is required.

If an average voltage of 5 V is to be applied to this load, its electric capacity (F) is 8640 ＝ 5 = 1730 (Farad) and 20 mA at 100 mA.
The load requires 1728/5 = 345.6 (farads).

[0007] By the way, if a solid-state electric double-layer battery described later is used, an electric capacity of about 1000 farads can be obtained by one unit. Therefore, with the above-mentioned 100 mA load, two solid-state electric double-layer batteries can be connected in parallel. All right, 20
At the mA load, one solid-state electric double layer battery may be connected.

On the other hand, a solar cell generator that supplies current to two solid-electrode double-layer batteries is a 10 cm × 10 cm square in the case of a polycrystalline generator,
1.5 W at V, 2.5 A (conversion efficiency 15
%), If a 15 V solar cell generator is to be made, 25 sheets of 10 cm × 10 cm are required.

At this time, the backup time (T) to the load is about six days as shown in Table 1.

[0010]

[Table 1]

On the other hand, the charging time (t) for the capacitor is shown in Table 2.
As shown in FIG.

[0012]

[Table 2]

FIG. 4 shows the above.
According to the solar cell drive circuit based on the above-described equipment, once the electric power is stored in the solid-state electric double-layer battery corresponding to the electric storage device 4, a power device that allows an average current of 20 mA throughout the day, such as a communication device or a personal computer It shows that it can be operated without replenishing sunlight for as long as 6 days.

[0014]

However, as in Japan and Northern Europe, there are cases where the sunshine is missing for more than six consecutive days.
In such a case, the technique proposed above causes a disadvantage in terms of power storage.

The present invention proposes a solar cell drive circuit capable of avoiding the above disadvantages.

[0016]

SUMMARY OF THE INVENTION The present invention relates to a generator for converting light into a current, which is composed of a single crystal, polycrystal, amorphous or compound semiconductor, and stores electric energy generated by the generator. A power storage device comprising a solid-state electric double layer battery that gradually discharges the stored energy to a load body without assistance from another power source during a period in which there is no supply current from the generator, and connected in parallel with the power storage device; A balancer that activates a contact only when the capacity of the battery reaches a voltage level at which power cannot be supplied to the load circuit; and an auxiliary device that is connected in series with the contact of the balancer and is energized only when the contact is closed. A battery comprising: a battery as a secondary battery; and a voltage converter connected between the battery and the load, the output of which is connected to one terminal of the load. It is a battery-powered circuit.

[0017]

In such a configuration, a conventional primary battery or secondary battery is connected in parallel with the above-mentioned battery, and the voltage between both electrodes of the battery is below a certain threshold as shown in FIG. By installing a balancer that includes contacts that only operate when the first condition is met, first aid measures can be taken.

That is, in the present invention, the primary or secondary battery is intended to back up the battery, contrary to the prior art. However, unlike the primary battery, the secondary battery can be charged a limited number of times, so that it can be charged to a certain saturation value (for example, 6 V) by a solar battery generator, and then the contacts can be disconnected. .

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a solar cell driving circuit, wherein 1 is a white light such as sunlight, 2 is a generator such as a single crystal, polycrystal, amorphous or compound semiconductor, and 3 is a generator. 2 is a diode for preventing backflow from the output side (output side).

Reference numeral 4 denotes a battery comprising a solid-state electric double-layer battery, which stores electric energy generated by the generator 2 and uses the stored energy to supplement the power by another power source during a period when there is no supply current from the generator 2. The discharge is gradually discharged to the load body 11 described later. FIG.
3 shows a discharge characteristic of the battery 4.

5 is a balancer, and this balancer 5
The contact 7 is connected in parallel with the capacitor 4 and operates only when the capacity of the capacitor 4 drops below a certain level.

Reference numeral 6 denotes a sensor incorporated in the balancer 5.

Reference numeral 7 denotes a contact, and the contact 7 and a battery 9 as an auxiliary secondary battery are connected in series. This battery 9 has discharge characteristics as shown in FIG.

Reference numeral 8 denotes a backflow prevention diode, which is provided as necessary.

Reference numeral 10 denotes a DC-DC converter, and 11 denotes a load. The converter 10 is connected between the battery 4 and the load 11, and the output of the converter 10 is connected to one terminal of the load 11. Thus, the voltage applied to the load 11 is kept constant.

In the circuit of the above-described embodiment, when the capacity of the battery 4 drops down to a certain level (5 V in this example), the balancer 5 is activated, whereby the normally closed contact 7 is opened. As a result, the battery 9 is energized and the level is maintained. Therefore, even if the cloudy weather exceeds six days, the battery 9 is energized by the balancer 5, so that the power supply to the load 11 is ensured.

[0027]

Since the present invention is constructed as described above, it is possible to obtain a low-cost, high-power solar cell drive circuit which is almost permanent and does not cause any depletion in power supply. it can.

[Brief description of the drawings]

FIG. 1 shows a drive circuit according to the present invention.

FIG. 2 shows a discharge characteristic of a battery.

FIG. 3 shows a discharge characteristic of a battery.

FIG. 4 shows charge / discharge characteristics of a large-capacity battery.

[Explanation of symbols]

 2 Generator 3 Diode 4 Battery 5 Balancer 7 Contact 10 Converter 11 Load

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H02J 7/34 H01G 9/00 301Z H02M 3/155 H01L 31/04 K

Claims (1)

[Claims] And a generator configured to convert light into a current. The generator includes a single crystal, a polycrystal, an amorphous or a compound semiconductor, and stores electric energy generated by the generator. A capacitor consisting of a solid-state electric double-layer battery that gradually discharges this to a load without assistance from another power source during a period in which there is no supply current from the generator, connected in parallel with the capacitor, and the capacity of the capacitor provides power to the load circuit. A balancer that operates a contact only when a voltage level that cannot be supplied is reached, a battery as an auxiliary secondary battery that is connected in series with the contact of the balancer, and is energized only when the contact is closed, A voltage converter connected between the load and a load, the output of which is connected to one terminal of the load.