In our world, quite a lot of people are engaged in homemade experiments in home laboratories and workshops. For some, it is a way to assert themselves, for others, it is a desire to develop their abilities. So what if it’s an experiment made from hastily glued parts. The main thing is that the device or circuit works. Today we will analyze just such an invention, made practically on our knees. However, it is based on unshakable principles and laws of physics that cannot be denied.
We will talk about a flashlight that works without batteries. Perhaps someone has already seen on the Internet the simplest Faraday generator, which allows you to light a small LED with a few movements of the conductor in the winding. Assemblies from an almost dead battery, autotransformer and transistor, which are capable of powering a 3V LED at an initial voltage of tenths of a volt, are also no longer uncommon.
Here the author went a little further, modernizing the device circuit, adding a rectifier, a supercapacitor (ionistor), resistance and completely eliminating the power source. As a result, the flashlight's operation has become much more stable and efficient. And if you shake the case for a few minutes, it can be charged for a long time of LED operation. How it works? Let's figure it out.
Hello to all readers and admirers of the Radioschema website! Today I want to talk about the creation of an “eternal” lantern. For a long time there has been an idea to assemble a flashlight that works using muscle power, converting the mechanical energy of rotation into light. This flashlight has a very big advantage over others - its battery cannot run out. But of course, it is not without its drawback - you will have to work to shine it on them. Therefore, its first purpose is to work in emergency mode (if the batteries are dead), when you urgently need to shine a light somewhere, for example, to screw in plugs in an electrical panel. Since during long-term work, a person will simply get tired of turning the handle of the flashlight.
So, there was an idea, but it was difficult for it to materialize, since it was necessary to assemble a gearbox with an electric motor and stuff it into some kind of housing, and for most radio amateurs the housing is a “stumbling block.” But this task has been radically simplified with the purchase of an inexpensive 3D printer. Now the construction of any housing for a radio-electronic device is limited only by the author’s imagination.
The first pancake, as usual, was lumpy: I printed out the case, not yet knowing what the finished device would look like, taking the first engine I came across as a generator. It turned out that even with a very fast rotation of the handle, there was not enough voltage for stable operation of the flashlight. Then, taught by bitter experience, I approached the question more intelligently. I took a bunch of existing engines and tested them for suitability for this project.
We do this: we clamp the motor shaft into a screwdriver, give maximum speed and measure the voltage and short circuit current of the motor. Accordingly, we select the best copy. According to my observations, it is best to take a high-voltage (12 -24 volt) and low-revving motor.
Further on the gearbox: I used factory gears, since my 3D modeling program does not have a library for constructing the latter and I am currently printing from PLA plastic, but it is not resistant to wear. The drive gear and motor were used from some kind of electric corrector for car headlights, the intermediate (large) one from the disc drive of the AIWA music center, the last one (on the motor) from a children's car. The lens was used from a non-working Chinese headlamp. On the plus side: it has a lens and the ability to change the focal length. The light source is a three-watt LED; it, of course, is not used “to its full potential,” but in terms of reliability it has no equal (with such a low load).
As you know, such flashlights have one more drawback - they shine while you turn the handle. To at least to some extent smooth out this drawback, I installed ionistors in the case with a total capacity of two farads. And in parallel with the latter, a five-volt zener diode, since the maximum voltage for these ionistors is 5.5 volts, and the generator is capable of delivering up to 12 volts without load. There is a switch installed in the side wall of the device that disconnects the LED from the ionistors; if not needed, you can turn it off and a charge will remain in the ionistor for later use. In the off position, when the knob is rotated, the process of charging the ionistors occurs.
Mostly dedicated to newcomers to the world of physics and electronics. Today I will show you the simplest way to make an “eternal flashlight”, namely a Faraday generator. It is “eternal” because it can work without any energy sources, such as batteries or accumulators.
And so for it we need:
-copper wire with a cross section of 0.1-0.5 mm
-Neodymium magnets
-PVC pipe 10-15 cm long and 2 cm wide
-cardboard
-low voltage LED
- 10000 pf capacitor optional
The tools we need are:
-soldering iron
-glue gun
-scissors
And so, the first thing you need to do is cut out two washers from cardboard, with a diameter 4-5 mm larger than the diameter of the pipe:
Eternal flashlight or Faraday flashlight This is the name for a flashlight with an alternative power source. That is, this flashlight does not require batteries or battery charging. To “ignite” it, you need to shake it. The flashlight itself contains a generator and a battery.
Let's first take a look at the factory flashlight:
I tried to paint the design as much as possible. The point is that the cylindrical constant magnet dangles freely in the tube-housing between rubber stops or springs (wherever). And in the center of the tube there is a coil wound. When shaken, the magnet moves up and down inside the coil, creating alternating electricity in it.
Let's look without the case.
We see a solenoid, a cylindrical magnet, limiters, a small board with diodes, a switch, and batteries. Oh yes, and the LED on the board.
Shake the flashlight and turn it on. Works!
Here's our prototype:
Tick-tock box. The tube on which the reel is wound is the body of a ballpoint pen. A couple of magnets from a hard drive, there are some there. Yes, capacitors are used instead of batteries. White LED. a couple of diodes.
There is a peculiarity of coil winding. As you probably noticed from the diagram, the coil consists of two windings, the total length of the coil is 40 mm. Divide mentally hit. In the first half, we wind 600 turns of the thinnest wire with a diameter of approximately 0.08 mm. And in the second half there are 600 turns. That's all - the two-section coil is ready. Further according to the diagram.
A flashlight is an indispensable thing. And if this is an eternal flashlight, then it simply has no price. It can come in handy at any moment: there is a power outage in the apartment, an unforeseen situation can happen on a trip, in the garage, at the dacha. Just imagine what will happen if the battery runs out at the most inopportune moment. But if the flashlight has a dynamo, then there is nothing to worry about. You will always be with the light.
The dynamo flashlight is different from others in that it does not have batteries. It may have:
The eternal flashlight can work without a time limit. The service life depends on the durability of the light bulb built into it. Modern dynamo flashlight - LED. It can work for more than ten years continuously due to autonomous charging.
It is also called a Faraday flashlight. The device is quite simple. The lamp has a metal core and a coil. When they interact, an electric current arises. The eternal flashlight is equipped with a Ni-Mh battery. One or more LED lamps are installed in the lantern. If there is one lamp, then it is placed in the center, if there are several, then around the center.
A rechargeable dynamo flashlight, due to the fact that it does not require batteries to function, is in demand by hunters, fishermen and tourists. Real dynamo lights are quite expensive, but they serve the purpose - they really last a long time and provide a decent level of quality.
The Eternal Flashlight is indispensable for true trackers. There is no need to save money when choosing a flashlight.
Advantages of a Faraday flashlight:
There are quite a large number of options for eternal flashlights, designed for various situations and for use in performing various jobs.
A Faraday flashlight does not have batteries. You can use it without replacing lamps for 11 years. It withstands wet weather well and can be used even in the rain. The capacitor has a large electrical capacity. In order for the device to charge, you just need to shake it. The LED is equipped with a lens, so the luminous flux power is increased.
Lightweight and compact. Made of plastic.
This option is very convenient because you don’t need to hold it in your hands. It is attached to the forehead using elastic bands. Works without batteries.
There is a charger for charging. Using a cord, it is connected to a charger equipped with a rotating handle. After working the pen for a minute, you can illuminate the space for an hour. The device can be used to recharge a mobile phone. The adapters are designed to charge a Nokia phone. It has small dimensions: 5 x 6 cm. The body is made of plastic.
A special feature is the presence of additional options. This model can serve as chargers for mobile phones and cameras. Charging will be enough for half an hour of operation of electronic devices. All additional adapters are included.
It can operate in two modes, weak on one LED and normal on three. Charging for a minute provides light for one hour.
Overall dimensions - 15.5 x 5.5 x 4.5 cm, plastic case.
This model also does not require batteries. There is a handle on the body, the rotation of which charges the battery.
3 minutes of rotation of the handle - 40 minutes of continuous illumination. Three LEDs installed. It has several operating modes - flashing, gentle mode with 1 LED and normal mode, when all three LEDs light evenly. Impervious to water, can work successfully at a depth of 10 meters. The rotation angle is 320 degrees. It is very convenient - it can be secured and rotated in the desired direction.
Overall dimensions are 151x50x40 mm. Weight is approximately 150 g. The model comes in a plastic shell.
These models are presented in the form of an LED flashlight powered by light energy. The body of the light device is equipped with a solar battery, which is the main source of energy. For most models, this source is not the only one. There is also a dynamo built into the housing.
The handle leading to the dynamo rotates to power it. This action charges the battery. Thus, this model works both from light energy (solar battery) and from a dynamo. Due to this combination, the operating time of the flashlight increases. It can operate on these energy sources for an hour and a half. If the lamp goes out, it can always be recharged dynamically.
The advantage of the model is its resistance to moisture. It can remain operational at a depth of five meters under water. LEDs installed in the flashlight can “live” 50,000 hours.
Dimensions of the light device: 147x 61x 45 mm. Weight is about 180 g. The body is made of plastic.
The device is multifunctional. It has a convenient ergonomic housing, in which a fairly powerful LED is installed. The housing contains a radio receiver and an alarm system equipped with a siren. Such functions will be appreciated by tourists, mushroom and berry pickers, gardeners and car enthusiasts.
The good thing about a dynamo flashlight is that it is independent of the power source. The light device has a manual mechanical drive, with which you can charge the flashlight if there is no power supply nearby. The kit is equipped with headphones, and a speaker is built into the body. Manual charging takes a minute. This is enough for the lantern to shine for ten minutes without interruption.
The downside of this option is that it is susceptible to water.
Watch it in our video? how to upgrade the simplest dynamo lantern.
