Now a lot of customers are constantly turning to new industries, which makes many of our customers are constantly expanding contact network to do business. In the next five years, the demand for medium voltage frequency transformer in various industries will lead to a completely different market of medium voltage frequency changer. Facilitating these changes will be more important than ever before in a challenging economic environment.
Customers who do the power business sum up some principles concerning the quality in the recycling process. The transformer is mainly composed of iron cores and windings. The conductivity for all copper wires is the best, with the lowest heat. The second kind is copper-clad aluminum wire, the aluminum wire is seriously hot. Iron core quality is also selective, the simplest way to determine the quality of the iron core is that the iron core is wound by a certain turn number of coils and is powered by the corresponding alternating current according to the design plan of the transformers. By measuring the size of the current, you can determine the core quality, small current shows the core is of better quality. These common senses are indispensible to avoid purchasing the low-quality transformers,

1. Identify the Power Transformer
1) To identify from the shape: the iron core for the common power transformer has two kinds, including E-shaped and C-shaped.
E-shaped core transformer is the shell-type structure (coil is wrapped by the iron cores), using the high-quality silicon steel sheet D41.D42 as the iron core, it’s widely used.
C-shaped core transformer adopts the cold-rolled silicon steel strip as the iron core, with small magnetic leakage, small size, the core-type structure (iron core is wrapped by coil).

2) To identify from the leading-out terminal number of the winding: there are two windings for power transformer, i.e. primary winding and secondary winding, so there are four leading-out terminals. In order to prevent AC noise and other interferences, sometimes a shield layer is often added between the primary winding and secondary winding for some power transformers, the shield layer should be at the grounded end. Therefore, the connecting terminals for the power transformer are at least four pieces.

3) To identify from the laminated method of the silicon steel sheet: The silicon steel sheet for E-shaped power transformer is cross-inserted, without leaving the air-gap between E-chip and I-chip, the whole iron core matches exactly. A certain air gap should be left between the audio input and E-chip & I-chip of output transformer, which is the most intuitive way to distinguish the power and audio transformers. As for the C-shaped transformers, these are generally the power transformers.

2. Power Estimation
The transmission power for the power transformer depends on the material and cross-sectional area of the iron core. The so-called cross-sectional area, whether E-shaped shell construction or E-core structure (including the C-shaped structure), refers to the cross-sectional (rectangular) area of the core column wrapped by the winding. After measuring the cross-sectional area S of the iron core, the transformer power P can be estimated according to formula P = S2 / 1.5. In the formula, the unit for S is cm2.
3. Measurement to the winding voltages:
To make use of an unmarked power transformer, the primary winding should be found, then the output voltage for secondary winding should also be distinguished from them, which is the most basic task.