JPH10339714A - Electronic circuit and device for checking dry state of soil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To notify the dry state of soil by measuring the electric resistance of soil. SOLUTION: This device is composed of a power source 1, a resistor 2, a transistor 3, an LED 4 and electrodes 5a and 5b. The (+) side of power source 1 is connected through the resistor 2 to the base of NPN type transistor 3. Further, the (+) side of power source 1 is connected to the collector of the transistor 3. The emitter of the transistor 3 is connected to the anode of the LED 4, and the cathode of the LED 4 is connected to the (-) side of the power source. One side 5a of electrodes is connected to the emitter of the transistor 3 and the other side 5b is connected to the (-) side of the power source. When soil is dry, the LED is turned on and the dry state is notified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring circuit and an apparatus suitable for measuring the dryness of soil in horticulture and indicating when to water.

[0002]

2. Description of the Related Art Plants die when there is no water, and roots rot when there is too much water. Therefore, it is necessary to notify a proper timing of watering. Conventionally, when checking the dryness of soil, the soil has a high electric resistance if the water content is low, and a low electric resistance if the water content is high. It is known that the content of can be measured. Therefore, a device for supplying water when the electric resistance of soil is measured and exceeds a certain level has been devised. For example, the electrical resistance is measured by an electronic circuit as shown in FIG. 8 described in the 6th Home Electronics Edition of Electronics Production Ideas Issued by QC Publishing Company, the dry state is checked, and if the dry state exceeds a certain level, For example, a pump was operated to supply water.

[0003]

Problems to be Solved by the Invention The conventional electronic circuit is considerably complicated, and requires two kinds of power supplies, 12 V DC and 100 V AC to operate the pump, and has a problem that it is expensive. .

The present invention eliminates the disadvantages of the prior art described above,
It is an object of the present invention to provide a dry state checking device capable of detecting an inexpensive soil dry state with a simple electronic circuit.

[0005]

Means for Solving the Problems The electronic circuit is made simple by using a resistor, a transistor and an LED as shown in FIG.
Turn on the ED to indicate that it is dry.

[0006]

For example, in FIG. 1, when the resistance between two electrodes inserted in the soil increases, the voltage applied to the base of the transistor increases, and the voltage is calculated from the sum of the base-emitter voltage of the transistor and the standard voltage of the LED. When the level rises, an electric current flows through the LED and the LED lights up, indicating that the soil is dry.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an electronic circuit according to a first embodiment of the present invention, which comprises a power source 1, a resistor 2, a transistor 3, an LED 4, and electrodes 5a and 5b. The + of the power supply 1 is connected to the base of an NPN transistor 3 via a resistor 2. Further, + of the power supply 1 is connected to the collector of the transistor 3. The emitter of transistor 3 is LED4
And the cathode of the LED 4 is connected to-of the power supply. One of the electrodes 5a is connected to the emitter of the transistor 3, and the other 5b is connected to the negative side of the power supply. Now that the electrodes 5a and 5b are inserted in the soil, when the moisture content in the soil decreases, the electric resistance between the electrodes increases, the base voltage of the transistor 3 increases, and the current between the collector and the emitter increases. Flows, thereby causing a current to flow through the LED and illuminating the LED, thereby indicating that the soil is dry. In the electronic circuit of the present invention, it is possible to form a simple circuit configuration of one resistor, one transistor, and one LED and two electrodes, and the standard voltage required to light the LED is 1.5 to 2 V. 3 power supplies
V is sufficient, an inexpensive battery can be used, and a soil checker can be manufactured at extremely low cost. In addition, by making the resistor used in this electronic circuit a variable resistor,
Since the value of the electric resistance of the soil required for turning on the LED 4 can be changed, the dry state when the LED 4 is turned on can be changed. That is, in the case of a plant that prefers drying, the value of the resistance 2 is set to a large value, and unless the electric resistance of the soil increases, that is, the LED must be dried more.
4 does not light. Conversely, in the case of a plant that prefers moisture, if the value of the resistor 2 is set to a small value, the LED 4 will light up if it dries slightly.

FIG. 2 shows a first embodiment of a specific shape of the present invention. A main body 8 containing the electronic circuit and the battery of the first embodiment, two electrodes 5a and 5b extending below the bottom surface of the main body 8, and a transparent plastic cover 6 on the upper side of the main body 8; It consists of. The transparent plastic cover 6 prevents the inside LED from entering the water when the LED inside is visible. The electric resistance of the soil is measured by inserting the electrodes 5a and 5b all the way into the soil, but the surface of the soil is easy to dry and the deep part is difficult to dry, so check the dry state of the deep part of the soil with many roots as much as possible For this reason, the electrodes 5a and 5b are partially covered with the coating 7, and the coating is peeled off, and the electric conduction portion is exposed. ing.

FIG. 3 shows a second embodiment in which an electronic circuit and a battery are built in a cylindrical tube, an LED 14 is placed on the upper side, and the LED 14 is covered by a transparent plastic cover 16. At the tip of the cylinder, there is a pointed electrode 15b adhesively fixed to a cap 17 and a battery 11
Connected to the minus side of b. An electrode 15 a connected to an electronic circuit of the substrate 12 is sandwiched between the main cylinder 13 having a screw formed on the inside of the tip and the cap 17 and the main cylinder 13.
It is adhesively fixed to the tip of. In the case of the present invention, as shown in FIG. 4, if half of the entire length is inserted into the soil, the electrode portion enters the soil, so that the dry state of the soil can be checked.

FIG. 5 shows a third specific example. In the case of a plant with many leaves, the LED is not visible because it is hidden by the plant if it is near the surface of the soil. In order to make it easier to see, the LED 4 is placed high at the tip of a thin tube 30 having a wiring protruding inside from the upper surface of the main body 18 and the LED 4 is surrounded by a forehead 31 at the same time. The electronic circuit configuration is the same as FIG. According to this embodiment, the lighting state of the LED can be easily known in a plant with many bushes, so that the plant does not die.

FIG. 6 shows an embodiment of a second electronic circuit for checking the dry state according to the present invention. The same circuit as the detection circuit shown in the first embodiment of FIG. It is inclusive. In FIG.
A resistor 22 and a switch 26 are provided between the resistor 5 and the electrode 5a. A connection between the resistor 22 and the switch 26 is made to the base of the transistor 23. The collector of the transistor 23 is connected to the + side of the power supply 21 in parallel with the transistor 3. . The emitter of the transistor 23 is connected to the anode of the LED 24, and the cathode of the LED 24 is connected to the minus side of the power supply 21 by LE.
It is connected in parallel with the cathode of D4. When the soil is gradually dried and the electric resistance between the electrodes 5a and 5b is increased, the base voltages of the transistors 3 and 23 are increased. Only higher than the base voltage of the transistor 23. Therefore, as the soil dries, LED4
Turns on first, and when the soil dries further, LED24
Lights up. Therefore, the dry state of the soil can be known in two stages, and it can be quickly determined whether watering is necessary or not. It should be noted that, like the electronic circuit in the first embodiment, in this electronic circuit, the resistance 2
And 22 are variable resistances, so that the timing of watering in a dry state according to the plant can be notified. Since a battery is used for the check circuit in this dry state,
Usually, when watering is sufficient, the LED is not lit. Therefore, the switch 26 is used to determine whether the LED does not turn on due to the battery exhaustion or whether the light does not turn on due to sufficient water.
Is provided. That is, the switch 26 is normally closed, and when it is opened, the circuit of the resistor 2, the resistor 22, and the electrodes 5a and 5b is cut off, the electrical resistance between the electrodes 5a and 5b becomes apparently infinite, and the soil is dried. It is the same as the state where
ED4 and ED24 light up. If the LED does not light, it can be determined that the battery has reached its end of life. This switch can also be applied to the electronic circuit in the first embodiment.

FIG. 7 shows a fourth specific example, in which LEDs 4 and 24 are placed on the upper surface of a main body 29 containing the above-mentioned second electronic circuit 27 and battery 21, and a switch 26 is placed on the side surface. The method of use and the functions are the same as those of the first embodiment. Since the main body 29 is in the shape of a rectangular flat plate, by providing an insert 28 for a card on the front surface of which the name of a plant can be entered, it is possible to have both functions of a dry state check sensor and a name tag.

According to the present invention, the dry condition of the soil can be checked with an electronic circuit having a simple structure and a low-voltage battery, and the time for proper watering can be known, so that the plants do not die. .

[Brief description of the drawings]

FIG. 1 is an electronic circuit diagram of a first embodiment of the present invention.

FIG. 2 is an external view of a first embodiment of a dry state checking device according to the present invention.

FIG. 3 is a perspective view of a waist section of a second embodiment of the dry state checking device of the present invention.

FIG. 4 is a perspective view showing a use state of the dry state checking device of the present invention.

FIG. 5 is an external view of a third embodiment of the dry state checking device of the present invention.

FIG. 6 is an electronic circuit diagram of a second embodiment of the present invention.

FIG. 7 is a perspective view of a waist section of a fourth embodiment of the dry state checking device of the present invention.

FIG. 8 is a conventional electronic circuit diagram for checking a dry state.

[Explanation of symbols]

1, 11, 21 Battery 2, 22 Resistor 3, 23 Transistor 4, 14, 24 LE
D 5,15 Electrode 6,16 Plastic cover 7 Coating 8,13,18,29
Body 12, 27 Electronic circuit board 19 Spring 26 Switch 28 Name card 30 Thin tube 31 Amount

Claims (6)

[Claims] 1. An apparatus for measuring the resistance between two electrodes by inserting two electrodes into the soil and measuring the dryness of the soil, wherein an NPN transistor is connected to a positive side of a power source 1 via a resistor 2 The base of the transistor 3 is connected to the collector of the transistor 3, the emitter of the transistor 3 is connected to the anode of the LED 4, the cathode of the LED 4 is connected to the negative side of the power supply 1, and one of the electrodes 5a inserted into the ground is Electronic circuit for checking the dryness of the soil, characterized in that the emitter is connected to the negative side of the power supply and the other side is connected to the negative side of the power supply. 2. A dry state check device comprising a cylindrical main body containing the electronic circuit according to claim 1, a hemispherical transparent plastic cover on an upper surface, and two electrodes protruding from a lower part of the cylindrical main body. . 3. A ring-shaped body at the lower part of the cylindrical body in between the cylindrical body containing the electronic circuit of claim 1, a semi-resting transparent plastic cover on the upper surface, and a pointed electrode at the lower part of the cylindrical body. An apparatus for checking a dry state, comprising: 4. An LED is placed at a tip of a cylindrical main body containing the electronic circuit of claim 1, two electrodes protruding from the lower part of the cylindrical main body, and a thin tube protruding longer than the upper surface of the cylindrical main body. A dryness check device characterized by surrounding the LED with a forehead. 5. An apparatus for measuring a dry state of soil by inserting two electrodes into the soil and measuring the resistance between the two electrodes, comprising a power supply, a resistance, a transistor, an LED, and an electrode. In the detection circuit, a second resistor 22 and a switch 26 are inserted between the first resistor 2 and the electrode 5a, and a second transistor 2 is inserted between the second resistor 22 and the switch 26.
3, the collector of the second transistor 23 is connected to the + side of the power supply in parallel with the first transistor 3, and the emitter of the second transistor 23 is connected to the second LE.
The cathode of the second LED 24 is connected to the negative side of the power supply in parallel with the cathode of the first LED 4, and as the soil dries, the LEs are sequentially connected.
D4. An electronic circuit for checking the dry state of soil, wherein the LED 24 is turned on to notify the dry state. 6. A strip-shaped main body incorporating a dry state checking electronic circuit according to claim 5, two LEDs are placed on an upper surface, a switch is set on a side surface, and a plant is mounted on a front surface of the strip-shaped main body. A dry state checking device characterized by having an insert 2 for a card on which a name can be entered.