Batterys, rotating coils, small wind turbines, electric ships, and automatic flower watering devices shuttle in the track.
These five small inventions are relatively simple, and they all apply the physics knowledge learned in junior high school. It is very suitable for junior high school students with hands-on ability to make. Let’s explain how to make these three small inventions.
1. Batteries traveling in orbit
First of all, the tools we need to prepare are batteries, magnets and copper coils. Attach small magnets of the same polarity (both N or S) to the positive and negative terminals of the battery. Then put the prepared battery into the copper coil. At this time, you will find that the battery keeps shuttling in the copper coil.
Small magnets are the key point of this experiment. They not only generate a magnetic field, but also act as conductors, connecting the copper coil with the positive and negative poles of the battery. Even if a current is generated in the copper coil, at this time An energized copper coil generates a magnetic field according to the laws of electromagnetic induction and the right-hand rule.
2. Electric Small Boat
In this invention, we need to prepare batteries, motors, windmills, mineral water bottles, small wood chips, wires and tape. Cut the mineral water bottle horizontally, then put a small piece of wood in the middle of the mineral water bottle that has been divided into two, and fix it with tape. Then install the windmill and motor together, then fix the motor to the small wood piece and stick it with tape. The direction of the windmill is towards the stern of the boat (the tail of the mineral water bottle).
Then use wires to connect the battery and the motor. At this time, the motor drives the windmill, and the windmill generates wind energy, and the boat will move forward when placed in the water.
3. Automatic flower watering device
The principle of the automatic flower watering device is very simple, using the principle of atmospheric pressure. First we need to prepare a water bottle, and then two straws. Punch two holes in the water bottle, just big enough to insert a straw.
Then cut the straw to an appropriate length, insert the straw into the water bottle with the hole drilled, and then place the straw close to the water storage tray at the bottom of the flowerpot. When the water level in the water storage tray drops to the one of the two straws used as the air inlet, the other straw will suck out the water from the water bottle and water the flowers automatically.
How to make your own wind turbine
Abstract: As renewable energy wind energy attracts more and more attention, the coverage rate of wind turbines is also getting higher and higher. . Anyone who has seen a wind turbine knows that the three blades on each wind turbine do not rotate very quickly, so people think that the power generated by the wind turbine is not high. Then you know that the wind turbine How many kilowatt hours does it cycle? How to choose a small wind turbine? Let’s find out below. 1. How many kilowatt-hours of electricity does a wind turbine generate per revolution?
The power of wind turbines is different, and the electrical energy generated by each rotation of the wind turbine is also different. For example, the most common 2MWA direct-drive wind energy generator, when the wind energy is sufficient and stable, can generate 2,000 degrees of electricity every 60 minutes, and it takes 3.5 seconds for the fan blades to rotate once, and 60 minutes is 3,600 seconds, so The electricity generated by the generator per second is 0.56 kilowatt-hours, so the electricity generated by the fan of the wind energy generator for each rotation is 0.56×3.5 seconds, which is 1.94 kilowatt-hours of electricity.
2. How to choose a small wind turbine
1. Wind blades
It is best to use high-strength nylon composite materials, which have high strength and good toughness. Anti-ultraviolet, anti-corrosion, resistant to high winds, with good aerodynamic performance and unique strong wind stall protection characteristics.
2. Bearings
It is best to be imported or domestic first-line brands. Such wind turbines have high working efficiency, wear resistance, durability and long service life.
3. Magnetic steel
Magnetic steel is best to use rare earth neodymium iron boron permanent magnets, which have high efficiency, light weight, low energy consumption and high output power.
4. Anti-strong wind tail design
It is best to have a pre-biased tail rudder design, which can automatically and accurately align the windward direction, increase the output power while taking into account both adjustment and strong wind protection.
5. Carbon brush and brush ring structure
Using such a device, the electricity of the wind turbine can be transmitted from the carbon brush to the brush ring, and the brush ring will lead the electricity out; wind power generation When the machine rotates, it will rotate accordingly to prevent the cable from being twisted.
6. Connection method
It is best to use casing connection, which is highly safe, will not cause overspeed, and is very convenient to install. You must know that installing wind turbines in the wild is not only a technical job, but also a physical job. Ease of installation is a boon to field installers.
Power Plant Is there a permanent magnet on the stator of the wind turbine?
A windmill, motor, small wind turbine, light bulb, wires
In the process of converting wind energy into mechanical energy~
The mechanical power is required to be as high as possible~ < /p>
The weight of the windmill blades is smaller~
There is also a difference in how many blades you choose~
This needs to be tested by yourself~
You also need one Transmission speed change device~
Since the speed of the windmill will not be too high~
It is necessary to use a speed change device to speed up the speed~
Just use a gearbox~
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This step of converting mechanical energy into electrical energy~
Since the voltage required by lz is not large~
It is enough to use a general fixed magnetic pole generator~
The output voltage is unstable~
If necessary, add a voltage stabilizing circuit to the output~
No! Large generators all use magnets to rotate, which means that the rotor is a permanent magnet and the stator is just a coil. This is convenient for generating high voltage, because if you make the coil on the rotor, you must use an electric ring to connect the electric current.Current output, when the voltage is too high, sparks will be generated, which is not conducive to the stable operation of the generator. But using a coil as a rotor can also generate electricity, such as the motor on a tape recorder. If you spin it quickly, it will also generate electricity, but the voltage will be lower. As long as the coil cuts the magnetic lines, current will be generated, so whether the coil is used as a stator or a rotor, it can generate electricity. However, due to some practical considerations, large generators use coils as the stator and permanent magnets as the rotor!