JPH0315914A - Solar battery driver - Google Patents

Abstract

PURPOSE:To effectively use energy by permitting a current restriction circuit to intervene between a solar battery and a load, providing a voltage detection circuit and releasing restriction of the current restriction circuit when the solar battery comes to constant energy required for the start of said load. CONSTITUTION:The load 2 is connected to the solar battery 1, and the current restriction circuit 3 is intervened between the solar battery 1 and the load 2, whereby the voltage detection circuit 4 is provided in parallel with the solar battery 1. The current restriction circuit 3 is constituted in such a way that it is controlled by the voltage detection circuit 4 and the restriction of the current is released when the solar battery 1 comes to the constant voltage being set. When generated electric power comes to a voltage value, the voltage detection circuit 4 releases the current restriction of the current restriction circuit 3. Thus, it can be evaded that the load 2 is started when the start current cannot be obtained from the solar battery 1, and the need of enlarging the capacity of the solar battery 1 is eliminated to constitute the device compact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solar battery drive device for driving a load consisting of an electric motor. [Conventional technology] When a motor is driven by a solar cell, the starting current is larger than the operating current due to the characteristics of the motor, so if the sun's rays are weak, the motor may not start even if it can be operated. Therefore, in a structure where the motor is stopped, it cannot be started after it has stopped, and since the starting current is larger than the operating current, a voltage drop occurs due to the internal resistance of the solar cell, and the solar cell, which can obtain sufficient operating current, There were times when it became impossible to operate because it could not be started even if it became a beam of light. If startup is started at a voltage close to the voltage that allows startup, startup will stop due to a voltage drop, and depending on the transfer function of the load and solar cell response during this time, it may cause unstable startup at low speeds. A phenomenon of repeated stopping and stopping occurred, which not only made it impossible to start, but also caused problems with pumps and the like that were equipped to handle the load.

In order to solve this problem, Japanese Patent Application Laid-Open No. 60-74935
As described in the publication, an attempt has been made to use two large MS ponds and connect them in parallel and in series so that the voltage required for starting can be obtained. [Problems to be solved by the invention] However, the method described in JP-A-60-74935 has the problem that the solar cell becomes large, which inevitably increases the manufacturing cost. , it also had the problem of not being compact. The present invention was made in view of these circumstances, and
The purpose of this project is to provide a solar cell drive device that can be manufactured compactly and that can effectively utilize the energy of solar cells. [Means for Solving the Problems] The present invention provides a current limiting circuit interposed between a solar cell and a load, a voltage detection circuit for detecting the voltage of the solar cell, and a voltage detection circuit for detecting the voltage of the solar cell. When the required constant energy is reached, the problem is solved by canceling the current restriction by the current limiting circuit. [Function] When the amount of power generated by the solar cells reaches the energy required to start the load, the motor of the load is started, so the motor is reliably started, even though it has the generated energy to start. This can solve problems such as not being able to start. [Example] The present invention will be explained based on an example shown in the drawings. Fig. 1 is a diagram showing an ellipse of a solar battery drive device showing an example of the present invention, and Fig. The figure shows its characteristics. In FIG. 1, the solar cell drive device includes a load 2 connected to a solar cell 1, a current limiting circuit 3 interposed between the solar cell 1 and the load 2, and a solar cell 1 connected to a load 2. ,
A voltage detection circuit 4 is provided in parallel. The current limiting circuit 3 is controlled by a voltage detecting circuit 4, and is configured such that the current limitation is canceled when the solar cell 1 reaches a predetermined voltage. The elements constituting the current limiting circuit 3 may be general semiconductor elements capable of controlling current, such as thyristors and transistors. Further, the voltage detection circuit 4 is configured to detect the voltage when the solar cell 1 reaches an energy value that can start the load, and to control the current limit circuit 3.

Further, the voltage detection circuit 4 is provided with a capacitor 5, and this capacitor 5 may be a rechargeable battery. Load 2 is an electric motor to which a bong or the like is connected, and can be treated similarly if the starting current is larger than the operating current. In FIG. 2, line A is the no-load generated voltage of solar cell 1, and line B is the voltage when load 2 is activated. The voltage value C is determined by the voltage detection circuit 4 and the current limit circuit 3.
D indicates the voltage at which the current limit of the current limit circuit 3 is released. In such a configuration, when the solar cell 1 is exposed to sunlight, the solar cell drive device generates power generation energy proportional to the intensity of the sunlight due to its power generation function. When the voltage value shown in C is reached, the voltage detection circuit 4 releases the current limit of the current limit circuit 3. Therefore, the voltage of the solar cell 1 is applied to the load 2, and the load 2
The electric motor provided as When the load 2 starts, a large starting current flows, and this current causes a voltage drop due to the internal resistance of the solar cell 1.
The voltage applied to the load terminal, that is, the load 2, will decrease as shown by line D in Figure 2, but the voltage D that is applied to the load 2 will decrease. This must be the minimum voltage required to start load 2. Therefore, the voltage value C that releases the current limiting circuit 3 of the voltage detection circuit 4 must be set by adding the voltage that decreases due to the starting current of the solar cell to the minimum voltage at which the load 2 can be started. In this way, the voltage at which the current limit of the current limiting circuit 3 is released must be set in consideration of the starting voltage of the load 2 and the voltage drop due to the internal resistance of the solar cell 1, etc., so the magnitude of the starting current of the load 2 must be set. Determine the voltage (7!C) by the voltage (7! After that, stable operation can be performed. [Effects of the Invention] According to the present invention, it is possible to avoid starting the load 2 when the starting current cannot be obtained from the solar cell 1, and the capacity of the solar cell 1 is not increased unnecessarily. There is no need to do this, and it can be configured compactly.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a solar battery drive device according to an embodiment of the present invention, and FIG. 2 is a diagram showing its characteristics. DESCRIPTION OF SYMBOLS 1... Solar cell, 2... Load, 3... Current limiting circuit, 4... Voltage detection circuit.

Claims (1)

[Claims] In a solar cell drive device that drives a load consisting of an electric motor, a current limiting circuit is interposed between the solar cell and the load, and a voltage detection circuit that detects the voltage of the solar cell is provided, so that the solar cell is necessary for starting the load. When the energy reaches a certain level,
A solar battery drive device characterized in that the current restriction by the current limiting circuit is canceled.