Step-down transformer 1978

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It consists of a step-down transformer and a diode bridge (matrix) that rectifies the alternating current coming from the transformer into direct current.
Let's start with it, it consists of four very powerful diodes, brand unknown, the only thing we could see was “Made in the USSR”; when there is 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

The diodes are connected according to a standard rectifier circuit

This is what it looks like in this case

The connecting wires are used with a very large cross-section; all connections are made using bolts and nuts, otherwise, at high current, the insulation may ignite or the wires may simply melt.
Now let's move on to disassembling the compartment with the transformer, the top cover is held on by two bolts, unscrew it, remove the cover and take out the transformer itself

It, like any transformer of this type, has two windings, this is the primary winding to which 220 V is supplied and the secondary from which 12 V is removed
The primary winding consists of a copper wire with a cross-section of 1 mm; the mains voltage is connected directly to it

Now let's move on to the secondary winding at 12 V, here are the winding taps

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

That's all we can do is be proud of the quality of the power supply, because it is now 32 years old, and it still continues to work properly.
Video of an attempt to short-circuit a transformer