Eternal flashlight without batteries

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 ignite a small Light-emitting diode. Assemblies from an almost dead battery, autotransformer and transistor, which are capable of powering at an initial voltage of tenths of a volt Light-emitting diode on 3V is 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 LED. How it works? Let's figure it out.

Principle of operation

The device consists of several inductors that you can assemble yourself. The primary inductor actually serves as a power source or completely replaces its usual counterpart - the battery. Due to the movement of a rod of permanent magnets in it, an electric current is induced. Due to the oscillatory movements in the magnetic field, electric waves are created emanating from the coil at a certain frequency. A rectifier or diode bridge helps stabilize them and convert them into direct current.

Without a storage capacity, such a device would have to be constantly shaken, so the next element in the circuit is a supercapacitor that can be recharged like a battery. Next, a step-up transformer or voltage converter is connected, which consists of a toroidal ferrite coil and two windings - base and collector. The number of turns can be the same, and is usually 20-50. The transformer has a middle connection point at opposite ends of both windings, and three outputs to the transistor. The autotransformer increases tiny current pulses into sufficient ones for operation LED, and a bipolar transistor is connected to control them. A similar electrical circuit has different names in different sources: joule thief, blocking generator, Faraday generator, etc.

Eternal flashlight without batteries

The necessary resource base for homemade products

Materials:

  • PVC pipe, diameter 20 mm;
  • Copper wire, diameter – 0.5 mm;
  • Low-power reverse conduction transistor;
  • Neodymium magnets are round, size 15x3 mm;
  • Diode bridge or rectifier 2W10;
  • Resistor;
  • Supercapacitor or ionistor 1F 5.5V
  • Switch button;
  • Light-emitting diode white or blue at 5V;
  • Transparent epoxy resin type adhesive;
  • Hot glue;
  • Pieces of plywood, cotton wool;
  • Copper wiring insulation.
Tools:
  • Soldering iron;
  • Hot glue gun;
  • Hacksaw for metal;
  • File, sandpaper.

Flashlight making process

We will make the body of the flashlight from PVC pipes. Mark a segment 16 cm long and cut it with a hacksaw.

From the center of the segment we mark 1.5 cm in each direction. This results in a winding area 3 cm wide.

Next, we take a copper wire with a cross-section of 0.5 mm, leave one end about 10-15 cm long, and wind the wire onto the flashlight body tube according to the markings manually. You will have to wind quite a lot, more than half a thousand turns. The first few of them can be fixed with glue. We press the initial row of the coils tightly against each other, and make it strictly consistent.

At its maximum points the winding should be approximately half a centimeter thick. We clean both ends of the wire with sandpaper for reliable soldering.

The movable magnetic core of the coil can be either solid or assembled in parts. Neodymium magnets are selected according to the inner diameter of the PVC tube. The required length of the magnetic rod is experimentally obtained, through the vibrations of which an electric current will be created.

The author used ten 3 mm thick magnets to obtain a length that was as rational as possible for such vibrations, and at the same time equal to the width of the winding.

[center]

On the oscilloscope scale you can see the difference between the potentials obtained from the vibrations of one and ten magnets. The author received a voltage of 4.5V from the oscillations of the magnetic rod. It also clearly shows the cyclicity of the sinusoid in intervals of varying frequency.

At this stage, following the example of the author, you can connect an LED directly to the output ends of the coil and check its performance. As you can see in the photo, the LED reacts to the movement of the magnetic rod and the pulse current it creates.

Now you need to plug both ends of the tube so as not to hold them with your hands while shaking. To do this, use the same hacksaw to cut out several patches of plywood, process the edges with a file, line them with cotton wool on the back side to soften them, and place them on glue so they don’t fall out.

It's time to connect the rectifier. The diagram shown in the photo shows which two of its four contacts are connected to the coil. Such a diode bridge is capable of receiving alternating current and delivering direct current in strictly one direction.

A step-up autotransformer will help convert low spontaneous pulses from the primary coil into sufficient voltage to operate the LED due to the self-induction of one of the windings - the collector. Since it is connected to the base winding, a constant and stable electric current will be supplied to the supercapacitor in sufficient quantity. The resistor will limit the excess of permissible values. A capacitor of sufficient capacity was also selected by the author experimentally using measurements of outgoing signals with an oscilloscope.

This circuit is closed by a reverse bipolar transistor, which controls the incoming electric current to the LED.You can assemble the circuit without a board, since there are not many parts. We mount the switch button on one of the contacts coming from the autotransformer.

The author chose to assemble his improvised flashlight design using hot glue, while simultaneously improving the insulation of the contact groups. The switch button is located on the side of the flashlight body. The author pasted the main elements of the circuit one on top of the other from one of the ends. The closing element remains the LED, which can be enhanced with protective glass or a reflector.

Despite the unsightly appearance of the device, suitable only for laboratory-experimental home-made products, such a flashlight is quite functional and, on occasion, will not let the darkness disappear. It is easy to assemble such a circuit at home and at minimal cost. And the complete absence of batteries makes it a truly useful device for various emergency situations.

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Comments (17)
  1. Denis
    #1 Denis Guests 6 March 2018 19:41
    13
    For about 15 years, similar lanterns made in China have been sold for pennies in the markets. and yes, they work
    1. serger
      #2 serger Guests 15 March 2018 20:08
      3
      I had such a flashlight and it worked, but the body was made of plexiglass, so it shattered into pieces
  2. Guest Gennady
    #3 Guest Gennady Guests 12 March 2018 22:35
    4
    Interesting homemade product
    1. Sergey.
      #4 Sergey. Guests 18 March 2018 22:05
      5
      A “bug” flashlight is nothing superfluous, and there is no need to fence your garden with so many details.
      1. Guest Igor
        #5 Guest Igor Guests 12 November 2018 19:42
        2
        This is exactly the “bug” - our dear one, and at that time still Soviet...
  3. Alexander Volk
    #6 Alexander Volk Guests 18 March 2018 20:37
    0
    What a useful invention! If only you had come up with a Perpetomobile, you would have received a Nobel Prize and become a millionaire!
  4. Alexander
    #7 Alexander Guests March 27, 2018 08:34
    1
    It would be great to make a flashlight that works from electrical interference. You bring it to the wiring, and it lights up. Like some indicators, only without a battery.
    Or go even further. Flashlight powered by WiFi.
    Good luck.
    1. NickB.
      #8 NickB. Guests 27 March 2018 19:38
      0
      yeah, and it’s even better that it’s self-charging from an electric lamp on the ceiling, from the “plasma” of a TV, a smartphone... have you ever been to places where there are no power lines nearby, no JESM towers, no Pepsi Cola from hypermarkets, or even dogs from McDonald’s? ?
      1. monkey
        #9 monkey Guests 5 November 2018 14:02
        0
        This place is called the African jungle, where you definitely won’t need all these super-duper gadgets. there is a different way of life. live so as not to die
    2. asdfrewqha
      #10 asdfrewqha Guests 17 May 2020 12:36
      3
      on some good Darlington type bc517, assemble the same circuit, but receive power from grounding (-) and through an RF diode (D2E or D405) from the + antenna and that’s it. so the scheme is the same.
    3. asdfrewqha
      #11 asdfrewqha Guests 17 May 2020 12:40
      2
      try experimenting with two diodes and an LED. take two diodes (preferably HF) and put the plus of the diode to the minus LED minus diode - to plus. You connect the remaining ends of the diodes and take hold of them, and the minus LED must be applied to the stripped battery as grounding. Light-emitting diode It will barely glow. In theory, you can strengthen this and here is the lantern.
  5. Guest Victor
    #12 Guest Victor Guests December 8, 2018 04:02
    11
    Have you tried attaching a magnet to the ends of the tube so that the main battery of magnets hangs in the tube, like on springs?
  6. 10baset
    #13 10baset Guests February 28, 2019 10:31
    1
    Good topic. Develop the idea further into a new building and you can go on sale) A very necessary thing in the village!
  7. Guest Sergey
    #14 Guest Sergey Guests 27 March 2021 17:32
    2
    If the magnets are hung on a spring, such a homemade product can be installed, for example, on a bicycle.
    You drive along, the spring shakes the magnets, Light-emitting diode burns. The best dynamics.
  8. Nick
    #15 Nick Guests November 24, 2022 10:38
    0
    The bug is not as reliable, but more powerful.
  9. Paul
    #16 Paul Guests December 10, 2022 00:21
    0
    The thickness of the wires that would be wound on the toroid would be even greater. As for the beginning of the winding with the end of the other, this seems understandable, but the discrepancy between the circuit and the declared voltage and the absence of supercapacitors with a bridge on it are depressing.
    In general, the best driver that I came across from homemade products was a combined circuit. Blocking generator for the initial high voltage and a full-fledged generator on the 555th timer powered by this voltage. But now I can’t find where this circuit is :( Thanks to the author for the homemade product. On the sides of the coil, cheeks could be cut out of some semi-solid material. But the fact that a magnetic field is induced in the palm is already dangerous. It is better to place all this in an iron tube so that it was not aimed in the palm of your hand, although then the pipe would probably become magnetized... so you can improve this device further and further.
  10. Nikolay
    #17 Nikolay Guests July 2, 2023 07:37
    2
    Where is the full final diagram? And why is everything whipped up with hot glue (on snot)?