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1978 Step Down Transformer
At home, I found a 12 volt power supply used to charge the batteries. It looks like this

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It consists of a step-down transformer and a diode bridge (matrix) which rectifies the alternating current coming from the transformer to direct current.
Let’s start with it, it consists of four very powerful diodes. The brand is unknown. The only thing that was made out was “Made in the USSR” with a short circuit, the insulation on wires with a cross section of 2 mm instantly melts, and the diodes are almost cold. Here they are close up

Diodes are connected according to the standard rectifier circuit.

This is how it looks in this case.

The connecting wires are used in a very large cross-section, all connections are made by means of bolts and nuts, otherwise, at high current, ignition of the insulation may occur or the wires may simply melt.
Now let's move on to disassembling the compartment with the transformer, the top cover rests on two bolts, unscrew the cover and remove the transformer

On it, like on any transformer of this type, there are two windings, the primary one is supplied with 220 V and the secondary one with which 12 volt is removed
The primary winding consists of a copper wire with a cross section of 1 mm; the mains voltage is directly connected to it.

Now, let's go to the secondary winding at 12 in here are the taps of the winding

This winding no longer consists of a wire, but of a copper tape 1.5 mm thick and about 4 mm wide. Such windings are used in welding machines, since the resistance of such a tape is small and hence the high current strength I did not dare to measure it, in a similar situation I already lost one ammeter by 20 amperes, and the tape because it takes up less volume compared to a cylindrical shape conventional wire, as the cylinder has less contact area.
Proof of high current may be a short circuit reaction.

And that’s all it remains to be proud of the quality of manufacturing the power source, because he is now 32 years old, and he still continues to work properly.
Video trying to short-circuit the transformer

come back
Comments (6)
  1. Danbaz
    #1 Danbaz Guests September 26, 2011 22:09
    0
    And what is it for? to brag that at home such a Soviet miracle lay?
  2. Levsha
    #2 Levsha Guests March 10, 2012 17:39
    1
    That's how they did in the Soviet years.
    good trance. spot welding can stir up from it)))
  3. Sergey
    #3 Sergey Guests May 13, 2013 10:10 PM
    0
    Funny post. )) To search with a screwdriver - disassemble charging? Yeah, that's cool.
    But only this is not to the “Do it yourself” heading, you need another “Break it yourself”. Well, as for the transformer, there is practically nothing to spoil there. We caught a Sovdepovsky welder in the lake, hefty with an adjustment knob, washed it - dried it, it works. It doesn’t even pierce the case.
  4. Stone
    #4 Stone Guests November 22, 2013 17:50
    0
    In principle, this is infa for the future, how to squeeze the maximum current at the smallest dimensions. So thank you from me.
    Suppose I need to get an awesome current at 1.5V at the output. A large diameter wire can not be stuck in a trance, without disassembling, but the tape can easily be inserted.
  5. Nikolay
    #5 Nikolay Guests May 1, 2017 11:21 p.m.
    0
    It is these transoms in the same case that are used in our production as a portable source for 12 volt transfers. In photo 6 there are three bolts, one free. Through it, a fuse in the form of a bug wire is included in the circuit break.
  6. student
    #6 student Guests December 8, 2017, 21:20
    2
    10 amp diodes from the series (B-10 voltage class). I put these in a 50 amp power supply, hesitated, and screwed hefty heatsinks to them. At a current of 50-60 amperes, the bridge heated up to about 40-45 degrees in 4 hours. Why? Yes, because without radiators, the case would come out 2 times smaller and lighter, and the unit only works 20 minutes a day. You will do what on them - feel free to put without a radiator, the current rating is calmly kept.

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