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Here we will upgrade the miniature flashlight pen. There was an incandescent light bulb. This flashlight showed a significant decrease in the brightness of the glow of the incandescent lamp when the batteries were seated. And of course, low efficiency and durability. But we will fix it.

Light-emitting diode! - Here is the solution to our problems. But changing the LED is not all. It is necessary to assemble a mini converter for the LED. There were two batteries in our lamp, so we will hide the converter in place instead of one of the batteries.

Let's look at the circuit.


The diagram shows a generator - converter. Excitation is achieved by transformer coupling.

The circuit used a KT315 transistor, a super-bright LED.
We will talk about the transformer separately. For its manufacture, a ferrite ring is required - an approximate size of 10x6x3 and a permeability of about 1000 HH. The diameter of the wire is about 0.2 mm. Two coils of 20 turns each are wound on the ring. If you do not have a ring, then you can use a cylinder that is similar in volume and material. Only it is necessary to wind already 60-100 turns for each of coils. An important point: you need to wind coils in different directions. At worst, you can use a nail, but a large nail, and even turns for one coil already requires about 150. In addition, the efficiency of the nail is much lower than that of ferrite.

Let's get down to business. We disassemble the flashlight. All its parts are clearly visible.


So - we make the case for our converter.


We make a cylinder on the batteries. It can be made of paper or use a piece of any rigid tube of non-conductive material. current.

We make holes along the edges of the cylinder, wrap it with a tinned conductor, pass the ends of the wire into the holes. We fix both ends, but leave a conductor piece from one of the ends: so that the converter can be connected to the spiral.


Let's assemble the converter itself. Let's start with the transformer, I didn’t have a ferrite ring (and it wouldn’t fit into the lantern), so I used a cylinder of the same material - the cylinder was removed from the inductor from the old TV.


The first reel is carefully wound on it. The turns are fastened with glue. I climbed about 60 turns. Then the second, dangles in the opposite direction. I got it again 60 or so; I definitely didn’t count it - I could not wind it neatly. We fix the edges with glue.

We assemble the converter according to the scheme:


Everything is located as in the figure: a transistor, a capacitor, a resistor, etc. Passive and active elements are assembled, solder the spiral on the cylinder, the coil. The current in the coil windings must go in different directions! That is, if you wound all the windings in one direction, then swap the conclusions of one of them, otherwise generation will not occur.

It turned out the following:


We insert everything inside, and use the nuts as side plugs and contacts.

Solder the coil leads to one of the nuts, and VT1 emitter to the other. We glue it.
You got something similar to what is shown in the previous figure.

Now you should make an LED bulb. You and I have already done this, so we will not stop.


One moment: there should be a minus of the LED on the base. Otherwise, nothing will work.
There was another solution to the problem. Of course, you can create a converter module with an LED in one housing directly. In this case, as you probably already noticed, you need only two contacts.


As is clear from the figure, the converter is a "substitute" for the second battery. But unlike her, he has three points of contact: with the plus of the battery, with the plus of the LED, and the general case (through a spiral). However, its location in the battery compartment is certain: it must be in contact with the plus of the LED. Simply put, the assembly sequence in the picture cannot be changed.

Flashlight in work:


Such a flashlight is more economical and due to the lack of a second battery is light. And the main advantage! All details can be found in the landfill!

Good luck

come back
Comments (18)
  1. [) eNiS
    #1 [) eNiS Guests August 3, 2010 21:35
    0
    But can I use anything other than KT315?
  2. NOTFRONT
    #2 NOTFRONT Guests August 4, 2010 06:10
    0
    ct 3102 for example, but in principle of any of this structure.
  3. [) eNiS
    #3 [) eNiS Guests August 5, 2010 11:22
    0
    understandably
  4. Ulad
    #4 Ulad Guests January 31, 2011 17:41
    0
    A KT814A is suitable, and you can take a capacitor at 220uf ??? book
  5. Ulad
    #5 Ulad Guests January 31, 2011 17:47
    0
    Can I wind the coil on a piece of the rod from a regular handle 25 mm long and how many turns are needed and what is the diameter of the wire ??? bookbookbook
  6. Ulad
    #6 Ulad Guests January 31, 2011 17:52
    2
    And can you take a KT814A transistor, a 220μF capacitor, and wind the transformer on a piece of the rod from a regular ballpoint pen with a long 25mm wire 0.1mm ??? book
  7. NOTFRONT
    #7 NOTFRONT Guests January 31, 2011 19:20
    0
    the transistor can be replaced, the capacitor - no (picofarads there!). Need to reel on the core of ferite!
  8. Ulad
    #8 Ulad Guests January 31, 2011 21:48
    0
    And it turns out if you take two capacitors with the marking 103 and 103 connected in parallel or with the marking 403, and a ferrite rod with a diameter of 7.5 mm will go and how long is it needed ???
  9. NOTFRONT
    #9 NOTFRONT Guests January 31, 2011 21:51
    1
    What to ask - TRY IT! Maybe it’s even better.
  10. Ulad
    #10 Ulad Guests January 31, 2011 21:57
    0
    I'm just new to this business and therefore want to know whether it will work out or not?
  11. Ulad
    #11 Ulad Guests January 31, 2011 22:15
    0
    And white will go to 4.5V ???
  12. Rybak27
    #12 Rybak27 Guests May 27, 2011 14:27
    0
    It will do. It costs me and burns brightly.
  13. Filiuk
    #13 Filiuk Guests December 12, 2014 00:42
    1
    Yes, this scheme is 100 percent working. Itself was assembled. It is only better to take the ferrite ring from the boards from damaged energy-saving lamps. (Not to be confused with fluorescent lamps), and wind only two windings of 9 turns of wire with a diameter of 0.1 - 1.0 mm. In this case, a capacitor is not needed. In general, any ferrite ring, not a large one, will do.
  14. Denis
    #14 Denis Guests October 16, 2015 22:28
    0
    Is it possible to use a 0.5 watt or 1 watt LED here?
  15. Roman
    #15 Roman Guests May 31, 2016 21:50
    1
    Not a bad scheme, thanks to the author. I selected the values ​​of the capacitor (1n) and the base resistor (120ohm).
    Interestingly, did anyone other than me try to calculate its efficiency in work?
    It turned out like this: at the input of the battery. 1.3A-1.3V
    Input consumption: at = 1.3V, current = 64mA, 10mm LED on the output, drop 3.3V at it, current 18.5mA. Total we get the efficiency = (3.3 * 0.0185) / (1.3 * 0.064) = 0.733. Sounds good, eh? Maybe someone did more?
  16. sergej
    #16 sergej Guests April 21, 2017 09:32
    0
    For bright lighting I used KT815, 961 and others.High-frequency power was selected by the brightness of the LEDs.
  17. Kod567
    #17 Kod567 Guests June 5, 2018 09:43
    0
    I made two such "substitutes" and the flashlight WORKS without batteries !!!!
  18. Guest oleg
    #18 Guest oleg Guests March 23, 2019 00:26
    0
    Wow, the LED is also on the battery. Nobel Prize

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