JPH03271793A - Solar sign - Google Patents

Abstract

PURPOSE:To improve the lighting efficiency of an EL panel by providing zero cross switches and the reverse bias channel by diodes in the switching channel of an inverter. CONSTITUTION:The one end of an LC circuit including the EL panel EL and an inductor L at least as one component of a series component is coupled to the coupling output terminal 20 of coupling output terminals 14a, 15b of the inverter and the other end is grounded. The charges charged up by the combined effects of the LC circuit, the zero cross switch mechanisms T1, T2 of the inverter channel and the bias channel by the reverse current bypassing diodes D1, D2 are recovered as a reverse flow current on the same supply power source side. The improvement in the lighting efficiency of the EL panel EL is made in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an internally illuminated display or sign that uses photovoltaic power generated by a solar cell as a power source for internal illumination.

[Prior Art] Various attempts have been made to use solar cells to power internally illuminated displays or internally illuminated signs at night. One method is to illuminate the dial of an outdoor clock with a mercury lamp.

However, attempts to use solar cells to power a full-fledged surface light source for internal illumination have hardly been successful. Various methods have been tried, but the power consumption of the fluorescent lamps used in these lamps is still in the tens of watts, and the power consumption is far too high to turn them on full-time at night. Even if solar cells are installed facing south under good sunlight conditions,
Due to both the design problem of the display, which requires a display area several to five times as large as the display area, and the cost of lighting, it is necessary to use fluorescent lamps for internal illumination of the surface display. At present, attempts to use solar cells to cover these costs have not been successful in most cases.

[Problems to be Solved by the Invention] The reason why it is difficult to use solar cells to cover the power for internal illumination of surface indicators and surface markings is that there is no surface illuminant with high lighting efficiency. is pointed out. The most well-known surface light emitter whose characteristics are extremely close to those of a perfect diffusion surface is the EL panel. However, the lighting efficiency (lumen/watt of luminous flux emitted per watt) of this EL panel is said to be about 1 lumen/watt at most, and even incandescent lamps and light bulbs are said to be more than 10 lumens/watt. Therefore, it is difficult to use an EL panel as a surface light source for internal illumination, and it is difficult to rely on the photovoltaic force of a solar cell as a power source, and it cannot be used for extremely limited purposes. Recently posted on the post
There has been an attempt called a solar post, in which an integrated molded body with a pond and a panel is installed, and the EL panel is turned on for less than 6 hours at night by the photovoltaic force generated by the attached solar cells. The area of the attached solar cell is about 5 to 6 times that of the attached EL panel (about A4 size). This is an attempt that was made possible because it is based on a post, which is an installation that is relatively easy to gain surface area, but it is difficult to use this system as an internal light source for general displays. is self-evident.

In this way, an attempt to use an EL panel, which is said to be an ideal fully diffused surface, as a surface light source for nighttime internal illumination of a surface display, and to cover the lighting power with photovoltaic power from solar cells, was successfully attempted and popularized. Since there is no immediate prospect that the efficiency of solar panels will be significantly improved, we have no choice but to consider measures to increase the lighting efficiency of EL panels by several times. Furthermore, even if attempts to increase the lighting efficiency of EL panels by several times are successful, further improvements in lighting equipment must be achieved in order to popularize solar signs.

Anyone who has had some experience with EL will understand that this lighting device, which is generally called an inverter, is a very complicated device.

It is said that the main reason for preventing the general use of EL panels, even without using solar cells as a power source, is actually this inverter, which is a light ignition device. The reason for this is that when trying to turn on an EL, it is necessary to create different inverters depending on the area of the EL and the lighting brightness. Furthermore, the current limit for the maximum area of an EL panel that can be lit using an inverter is approximately A4 size at most, and it is difficult to light up an EL panel that is as large as a postcard to A4 size. Currently, inverters are made by sorting them in stages into sizes that are approximately the size of the five avians.

When EL panels are larger than A4 size, it becomes difficult to manufacture EL light fixtures, and they are large and come with heat sinks. Therefore, looking at the applications in which EL panels are currently popular, EL panels with a small area and the same area are used in large quantities, such as backlights for LCD televisions and LCD backlights for laptops and 7-inch computers. Applications that can be mass-produced are the mainstream, and more than 90% of the total market is covered by such applications.

However, the application of solar signs is clearly different from such small-area, mass-produced applications of the same standard. First of all, the display areas of outdoor displays, commonly called signs, vary widely, and if the display areas were the same and were the size of an A4 board, they would not even be considered toys. .

Even if a standardized solar sign were to be put on the market, the display area would be about 1 square meter (1m”), about the size of an A4 sheet.
) It would be necessary to have around 10 types of similar ones, and it would also be necessary to support custom-made sizes. Considering these things, in order to popularize solar signs that use EL panels as a nighttime load, it is necessary to use EL panels. In addition to improving the lighting efficiency of the panel, it can be used with a wide range of devices with different EL areas.
In addition, it is essential to provide an EL lighting device that is simple to operate.

[Means for Solving the Problems] This invention solves the above-mentioned problems by configuring it as a single distribution.

The photoelectromotive force generated by the solar cell is stored in the secondary excretion, and the photovoltaic force generated by the solar cell and/or the electric power stored in the secondary excretion is used as a power source for lighting an EL panel having capacitive load characteristics. One end of an LCR or LC circuit including an EL panel of a solar sign and an inductor as at least part of the series-coupled component is coupled to the coupled output terminal of an inverter, and the positive/negative switch channel of the inverter is automatically switched when the current value becomes zero. A solar lighting system using an EL lighting circuit that is equipped with a switch mechanism using a zero-cross switch element or/and a zero-cross circuit that automatically closes (OFF) a channel, and a bypass channel using a reverse current bypass diode that bypasses the switch mechanism. Compose into a sign.

In addition, the EL panel of the solar sign is coupled to the output terminal of the secondary coil of a transformer, and an LCR or LC that includes a bipolar capacitor and the primary coil of the transformer coupled in series as at least a part of the series coupled component. One end of the circuit is coupled to the combined output terminal of the inverter, and the other end is coupled to the intermediate potential terminal or ground terminal of the positive and negative DC input power supplies of the inverter, and the positive and negative switch channels of the inverter automatically switch when the current value becomes zero. Close the channel (
The solar sign is constructed using an EL lighting circuit that is provided with a switch mm using a zero-cross switch element or/and zero-cross circuit that turns OFF), and a bypass channel using a reverse current bypass diode that bypasses the switch mechanism. .

[Function] The power stored in the photovoltaic force or secondary excretion of the solar cell, which is the power source for lighting the EL panel, is boosted or stepped down by a DC-DC converter to create a DC voltage at a different potential or a voltage at a constant potential. After converting it into
Due to the combined action of the C circuit, the zero-cross switch mechanism of the inverter channel, and the bypass channel using the reverse bypass diode, the charge that has been charged up in the EL panel or the bipolar capacitor is recovered to the power supply side as a reverse current. In addition, the LCR circuit or the inductance in the LC circuit controls the sudden rise of the current value when the switching element of the inverter is turned on (ON), and the zero-cross switching element is turned on (OF).
F) By setting the current value during operation to zero or close to zero, it is possible to eliminate or reduce the switching energy loss associated with the opening and closing operations of the switching elements of the inverter channel. Furthermore, by variably setting the switching frequency of the inverter, the lighting brightness of the EL panel can be variably set.

[Actually! Example j An example of the circuit configuration of a solar sign using the solar sign EL lighting circuit according to the present invention is as shown in FIG. is supplied to an EL lighting device 46 via a controller 45 to light the EL panel 44.The controller 45 may be of any known or known type.In the case of a solar sign having such a circuit configuration, two For example, the most popular voltage for the secondary discharge 43 is 12V, and the solar battery 42 of the present invention also uses a 12V charging type, and this battery power is switched by a controller at night and supplied to the EL light. The input voltage is used to turn on the panel 44.

Therefore, unless this is boosted in some way, E.
Since it is too low for L lighting, in the EL lighting circuit of FIGS. In the second B#I embodiment shown in Fig. 4, the DC input voltage to the inverter circuit is directly input to the inverter circuit.
An embodiment of the first aspect will be described with reference to FIG. 2, in which the voltage is 2V, converted to AC by an inverter circuit, and then boosted by a transformer to provide an EL AC load.

+e from the battery 43 supplied via the controller 45
A DC-DC converter 17 that boosts the voltage of volts to a DC input voltage to the inverter circuit is provided, and the EL panel 44
and an inductor L as at least a part of the series component, one end of the LC circuit is connected to the coupled output terminal 14a, 1 of the inverter.
5a, and connect the other end to the ground terminal 16.
do. Note that the DC-DC converter 17 uses a dual mode type, so that three terminals of ±E volts and the ground potential terminal 16 can be obtained from a single power supply of +e volts.

A positive switch channel 14b and a negative switch channel 15b are connected between the combined output terminals 20 of the inverter output power supply positive terminal 14a and the inverter output power supply negative terminal 15a.
are provided respectively. the positive/negative switch channel 14b;
15b automatically closes the channel when the current value becomes zero (
A zero-crossing element T] such as a thyristor, optical thyristor, or triac element that turns off), T2 or a switch mechanism provided with a zero-crossing circuit, and a reverse current bypass diode D that bypasses the switch mechanism.
, ,D are arranged to form an EL lighting circuit with a bypass channel.

Another embodiment of the first aspect will be explained with reference to FIG.

In the EL lighting circuit, the +e volt voltage from the solar cell is boosted to +2E using a DC-DC converter 27 that boosts the voltage to the DC input voltage to the inverter circuit, and a pair of capacitors CI of equal capacity.

The voltage of 2E volts is divided using C2, and the intermediate potential terminal 26 is taken out.
One end of the C circuit is coupled, and the other end is coupled 26a to the positive and negative output terminals 24a and 25a of the inverter. In addition, a positive switch channel 24b and a negative switch channel 25b are provided between the output power supply positive terminal 24a of the inverter and the combined output terminal 25a of the output power supply negative terminal, and the positive and negative switch channels are automatically switched off when the current value becomes zero. Zero-crossing elements such as thyristors, optical thyristors, triac elements, etc. that are closed (OFF), , T, ,
Alternatively, the switch mechanism is configured with a zero-cross circuit. Further, the switch mechanism is configured with an EL lighting circuit formed in a bypass channel by disposing bypass diodes D1 and D2, respectively, to reverse the bypass flow.

Next, a second R-type embodiment of the present invention will be explained based on FIG.

The DC input from the battery 43 to the inverter circuit is carried out at 12V as is, and after being converted to AC by the inverter circuit, the voltage is boosted by the transformer (TRNS) and the AC load is applied to the EL of capacity C.The EL panel is connected to the secondary of the transformer. One end of the LCR or LC circuit, which is coupled to the output terminal of the side coil and also includes the bipolar capacitor C3 and the primary coil of the transformer coupled in series as at least part of the series coupled component, is connected to the coupled output terminals 34b, 35b of the inverter. The other end is connected to the intermediate potential terminal 36 of the positive and negative DC input power source 34 of the inverter 2e, and a pair of capacitors C1 and C2 with equal capacitance are provided. The ends are cross-linked to the positive and negative current input power terminals 34a and 35a of the inverter.

Also, a compensation inductor L is inserted in series with the EL panel into the output terminal of the secondary coil.

A positive switch channel 34c and a negative switch channel 35c are provided between the combined output terminal 36a of the output power supply positive terminal 34b and the negative terminal 35b of the inverter, respectively,
The positive and negative switch channels 34c and 35c are closed (OFF).
A zero-crossing element T, , T2 = or a zero-crossing circuit such as a thyristor, optical thyristor, triac element, etc. is configured, and the switch mechanism includes a reverse current bypass diode D, , D2 to bypass.
An EL lighting circuit is constructed in which a bypass channel is formed by arranging the EL lighting circuit.

In addition, 11.21.31 in the figure is a pulse oscillator, 1.2.2
2.23 is a pulse selection inversion circuit, 111, 121.1
31 is an oscillation pulse, 121 and 221.321 are plus selection pulses, and 131 and 231.331 are minus selection pulses.

Next, the principle of power recovery by the LCR circuit in the present invention will be briefly explained.

Consider an LCR circuit as shown in Figure 5. That is, in FIG. 5, the current/voltage waveform while the switch S is turned on oscillates as shown in FIG. 6 if the value of R is below a certain limit.

That is, the electric charge charged in C(EL) flows backward toward the power source E at τl, and at time τ2, the electric charge charged in C(EL) flows backward toward the power source E at time τl.
EL) potential ■EL drops to Δ■. By the way, in this case, if S is a zero cross switch and automatically turns off at τ1, and a reverse bypass diode D is provided, then the current-voltage oscillation in this circuit will obviously be as follows at t=τ2. It stops.

That is, it is automatically locked at t=τ2. In this case, the charge corresponding to the reverse current between τ1 and τ2 is recovered to the power supply E from the capacitor C (EL).

The solar sign EL lighting circuit according to the present invention can be easily understood by considering that the power supply shown in Figure 5 is alternately switched between positive and negative using an inverter (although the direction of the diode is reversed).
.

That is, the current and voltage waveforms in the solar sign EL lighting circuit according to the present invention are as shown in FIG. In the original waveform, I(+) is the movement of the positive charge when the switching channel on the positive side is conductive, and I(-) is the movement of the negative charge. The shaded area corresponds to the charge recovery area due to backflow current. ! Looking at the pressure waveform, C (Vp - ΔV) every half cycle
It can be said that charges equivalent to C is E
is the capacitance of L.

T is the time of one cycle, but ΔT is the so-called Dead
Ti■e (idle time).

In the main lighting system, increasing the EL lighting frequency f only reduces Δτ, and for example, the current and voltage waveforms at O and 2 are not affected at all. Therefore, In this method, the EL lighting frequency can be increased to the limit where ΔT=O, but since the frequency fmax at which ΔT=O is τ2~2τ, in other words, in the EL lighting circuit according to this method, f <
Since the lighting frequency of the EL can be arbitrarily changed within the range of fmax, for example, the pulse oscillation frequency f of the oscillator shown in FIGS. 2, 3, and 4 showing the embodiment can be made variable by adjusting the volume PI, etc. For example, the EL lighting device can adjust and set the brightness i1g by frequency adjustment for an EL of any size.

Next, various experiments were conducted to confirm the effects of the solar sign according to the present invention.

We actually measured the lighting efficiency of EL panels A, B, and C5E used in solar signs, and the results are shown in the graph in Figure 8.The EL panels used were green-emitting ones manufactured by Fukubi Chemical Co., Ltd. The net emitting area of the EL panel is as follows.

EL A: 3766cnf EL B: 2851.4cafEL
C: 1367.4cnllELE
: 1094.4adEL lighting illuminance is for each EL
The surface illuminance of the panel was measured in the range of 4 to 10 Lx. The lighting device used has the configuration shown in Figure 2, and the lighting frequency can be set variably by adjusting the volume, and the inductance of the inductor is approximately 30H.
It is. The DC-DC converter converts 12V to ±50V dual mode, so in FIG. 2, e=12V and E=50V. The efficiency of the DC-DC converter changes depending on the output power, but a maximum efficiency of about 80% can be obtained when the output is 1.2iW, and the efficiency decreases as the output decreases. In Fig. 8, the horizontal axis is the input power to the lantern (that is, to the DC-DC converter), and the vertical axis is the luminous flux divergence rate (lumens/watt) per watt of input power emitted by the EL panel. ), as is clear from this graph, when the input power is 1 watt or more, the luminous flux divergence rate of the EL (including power consumption within the lamp) is 3 lumens/watt or more. Also, the plot of the measured values falls within the two dashed curves, but the reason why this trend is downward to the left is due to the decrease in the efficiency of the DC-DC converter, and the two shapes themselves are different from each other. The effect of increasing the EL lighting efficiency of the solar sign according to the present invention is obvious from the value of 0 or more, which almost matches the efficiency curve. (In the conventional technology, it is said to be 1 lumen/Watt or less.) Next, using the same EL lamp, EL lamps with different area configurations
A solar sign lighting experiment was conducted in which the panel was lit at the same illuminance of 10Lx. The results are shown in the table of FIG.

This table lists the lighting frequency settings when solar signs having different EL panel area configurations are turned on at the same illuminance of 10Lx (lux).

There are nine configurations of the EL panel area from A+A to 2. Also, the net EL area is written in the upper row. A0A is two sheets of A lit in parallel, and the same is true for B+B and D1E.0 In the table, R indicates the sheet resistance value of the EL panel.As can be seen from this table, the solar sign according to the present invention It can be seen that a wide range of EL opening areas can be accommodated by simply adjusting and setting the frequency with one EL lighting device, and there is no need to create different lighting devices depending on the lighting area as in the prior art.

In addition, the outer dimensions of the case of the EL light fixture we made are 30 sets/m.
The size of the case was 60 m/m x 80 cm, and there was no heat sink, and even after 8 hours of continuous lighting, the rise in case surface temperature was less than 1°C DEG compared to the outside temperature.

The external dimensions of the large EL panels used are: EL panel B: 550m/ax 550■/@E
L panel A: 720m/length x 550mm/light, and in fact, there is no conventional technology that lights such a large EL panel with such a small lighting device, much less A+A, B+B. That fact is remarkable.

[Effects of the Invention] In the EL lighting circuit of the solar sign according to the present invention, the following effects are simultaneously realized in terms of energy, and the lighting efficiency of the EL panel is several times (3 to 4 times) that of the conventional technology. 〉 will also improve.

■ Eliminating or reducing power capacitance loss due to EL panels.

■ Eliminate or reduce switching energy loss in the inverter switching channel.

Furthermore, by providing a zero-cross switch and a reverse bypass channel using a diode in the switching channel of the inverter, the current waveform mode for each cycle necessary to achieve the above-mentioned effects of the present invention can be automatically adjusted according to the area of the EL panel. locked (autolock) and therefore 1
Not only can the single lighting device accommodate a wide range of areas for different EL panels, but also the lighting brightness can be adjusted individually. In other words, as a third effect, by using the EL lighting circuit for solar signs according to the present invention: ■ One type of E can be used for solar signs with different EL panel areas.
The L lighting device allows a wide range of applications, and by adjusting the lighting brightness individually, it is possible to set the lighting brightness of the desired solar sign.

Note that even in a method in which a reverse flow bypass channel using a diode is provided in the switching channel and a zero-cross switch mechanism is not used, the switching element opening time (ON time) of the inverter channel can be changed depending on the area of the EL.
Although it is possible to achieve the effects of ■, ■, and ■ above by setting the time within a certain determined time range,
However, in this method (method that does not use a zero-cross switch), the switch element of the inverter channel is turned on.
When setting the time, it is necessary to set it while monitoring the current waveform or voltage waveform of the EL panel with an oscilloscope, etc., which is time-consuming and troublesome.

On the other hand, in the present invention using a zero cross switch mechanism, the inverter channel is automatically closed (○FF) by the zero cross mechanism, so the channel opening time (ON time) for each area of the EL panel can be monitored using an oscilloscope, etc. There is no need to set it manually; the EL light will automatically set it itself.

[Brief explanation of drawings]

The figures show an embodiment of the solar sign according to the present invention, FIG. 1 is a circuit diagram of the solar sign, and FIG. 2 is an EL circuit diagram of the solar sign.
A circuit diagram of the first Sat embodiment of the lighting circuit, FIG. 3 is a circuit diagram of another embodiment, FIG. 4 is an EL lighting circuit diagram of the second embodiment, and FIG. 5 is a circuit diagram of this EL point. The LCR circuit diagram used in the lighting circuit, Figures 6 and 7 are current and voltage waveform diagrams of the EL lighting circuit,
FIG. 8 is a graph showing the lighting efficiency of an EL panel using the solar sign of the present invention, and FIG. 9 is a table showing the lighting experimental effects of the solar sign. 14.24.34...Inverter input power supply plus terminal 15.24...Inverter input power supply minus terminal 16
...Ground (intermediate potential) terminal 17.27...DC-DC converter 42...Solar cell 43...Secondary electricity excretion 44...EL panel 45...Controller 46...EL point Light circuit T1. T2...Zero cross switch elements D1, D2
... Reverse current bypass diode C,, c, ... Pair of capacitors with equal capacitance C, ... Bipolar capacitor L ... Inductor Ll ... Compensation inductor (variable inductance)

Claims (8)

[Claims] 1. A solar cell in which the photovoltaic power generated by a solar cell is stored in a secondary battery, and the photovoltaic power generated by the solar cell and/or the electric power stored in the secondary battery is used as a power source for lighting an EL panel having capacitive load characteristics. In the signal, one end of an LCR or LC circuit including an EL panel and an inductor as at least part of a series coupled component is coupled to the coupled output terminal of an inverter, and when the current value becomes zero in the positive/negative switch channel of the inverter, The EL lighting circuit is equipped with a switch mechanism using a zero-cross switch element and/or a zero-cross circuit that automatically closes (OFF) a channel, and a bypass channel using a reverse current bypass diode that bypasses the switch mechanism. Features a solar sign. 2. A solar cell in which the photovoltaic power generated by a solar cell is stored in a secondary battery, and the photovoltaic power generated by the solar cell and/or the electric power stored in the secondary battery is used as a power source for lighting an EL panel having capacitive load characteristics. An LCR or LC circuit in which the EL panel is coupled to the output terminal of the secondary coil of the transformer and includes a bipolar capacitor and the primary coil of the transformer coupled in series as at least part of the series coupled component. Connect one end of the inverter to the combined output terminal of the inverter,
The other end is the intermediate potential terminal of the positive and negative DC input power supply of the inverter,
Alternatively, the positive/negative switch channel of the inverter is connected to the ground terminal and has a switch mechanism using a zero-cross switch element or/and a zero-cross circuit that automatically closes (OFF) the channel when the current value becomes zero, and a bypass for the switch mechanism. A solar sign characterized by using an EL lighting circuit provided with a bypass channel using a reverse current bypass diode. 3. 3. The solar sign according to claim 2, further comprising a compensating inductor inserted in series with the EL panel into the output terminal of the secondary coil of the transformer. 4. The power stored in the photovoltaic force and/or secondary excretion from the solar cell, which is used as the power source for lighting the EL panel of the solar sign, is boosted and/or stepped down by a DC-DC converter to generate a DC voltage of different potential or a constant voltage. 4. The solar sign according to claim 1, wherein the solar sign is converted into a potential voltage and then used as a DC input power source for an inverter. 5. A pair of capacitors having substantially equal capacities are connected to the other end of the LCR or the LC circuit, and the other ends of the pair of capacitors are cross-linked to the positive and negative DC input power supply terminals of the inverter. Solar sign as described in any one item. 6. The feature is that the electric charge that has been charged up in the EL panel or bipolar capacitor is recovered to the same power supply side as a reverse current by the combined action of the zero cross switch mechanism of the LCR or LC circuit and the inverter channel, and the bypass channel by the reverse bypass diode. The solar sign according to any one of claims 1 to 5. 7. Due to the effect of inductance in the LCR or LC circuit, the switching elements of the inverter are opened (
The inverter channel 7. The solar sign according to claim 1, wherein the solar sign is designed to eliminate or reduce switching energy loss accompanying the opening/closing operation of the switching element. 8. 8. The solar sign according to claim 1, wherein the lighting brightness of the EL panel can be variably set by variably setting the switching frequency of the inverter.