Sometimes, that stress removed from secondary winding of the transformer is not enough for that scheme which from it will eat, and there is no other transformer suitable on power. The master who has appeared in such situation will be helped out by the operation called rewind.
It is required to you
- - screw-driver;
- - hammer;
- - multimeter;
- - winding machine with the counter;
- - winding wire;
- - soldering iron, solder and neutral gumboil;
- - megger
Instruction
1. Make sure that the transformer is folding. If its core is assembled by gluing together by varnish, or, especially, welding and also if the device is pressurized in any way, then for rewind it is unsuitable.
2. Some transformers have several secondary windings. Connecting them it is consecutive, it is possible to receive various tension. If some of such windings are not involved, having included them is consecutive with already used, it is possible to increase voltage output, without resorting to dismantling of the transformer. Carry out all rerations at powered off. If the removed stress after alteration has not increased, and has decreased, so the additional winding is connected in the wrong phasing. Trade places its conclusions.
3. Having made sure that the transformer has folding design, it is possible to start its dismantling. Having removed fastening of the core, sort it easy blows of the hammer, remembering arrangement of plates. Having exempted the coil from the core, reel up on it the measuring winding having several dozen rounds. Isolate it, pull out conclusions outside then collect the transformer.
4. Connect the multimeter working in the mode of measurement of alternating voltage to measuring winding give the rated voltage of power supply on the primary winding of the transformer. Having separated number of rounds of measuring winding into the measured tension, you receive number of rounds on volt.
5. Calculate number of rounds of new secondary winding which needs to be included consistently from available, on the following formula: Ndop = (U2-U1) * (Nizm/Uizm), where: Ndop - required number of rounds of additional winding; U2 - tension which needs to be received; U1 - tension of the available secondary winding; Nizm - number of rounds of measuring winding; Uizm - stress removed from measuring winding. Again disassemble the transformer, wind measuring winding and instead of it reel up additional. Use wire of the same section, as at the available secondary winding, at the same time, you watch that diameter of the coil has not increased too strongly, otherwise the core cannot be put on. If it is impossible to observe this requirement, it is necessary to refuse alteration of the transformer.
6. Isolate additional winding, collect the transformer then include new winding consistently from secondary. Provide its correct phasing with the way described above.
7. After alteration of the transformer do not remove from it the power exceeding that on which it has been calculated initially at all. It is possible to calculate this power, having increased the removed stress by the consumed current.
8. By means of the megger make sure that leak between primary and secondary windings and also between each of them and the core is absent even after long warming up at the power removed rating. Make sure that during test do not appear smell of burning, smoke.