LAN transformer test cycle ratio and polarity

Why must the LAN transformer before the factory test cycle ratio and polarity.

Transformer is used according to the preset proportion and polarity conversion on both ends of the coil voltage of the device, the network is the role of transformer at the ends of the primary coil set according to the proportion of the voltage and polarity transformation to the ends of the secondary coil, it is in the local area network (LAN) data signal transmission system of a link, if the primary coil and secondary coil circle than the ratio of number of turns or wrong polarity, It will cause the voltage of the data being transmitted signal amplitude and polarity disorder, will cause the long transmission at the ends of UTP impedance mismatch, impedance mismatch in the data voltage signal transmission system will produce reflection interference voltage signal, amplitude, polarity disorder and reflection interference signal, etc., can make the data result in error voltage signal transmission system, and data transmission is not normal.

Therefore, the circle ratio and polarity of the network transformer are the indicators that must be tested before the product leaves the factory.

Electrical properties include:

Insertion loss (IL)

Return loss (RL)

Crosstalk (Crosstalk)

Common mode rejection ratio (CMRR)

Open circuit inductance (OCL)

Circle ratio (T/R)

Mechanical properties 

1. Solder ability

Resistance to Soldering heat

3. Vibration (Vibration)

4. Mechanical Shock

5. Flatness (if SMT module)

Environmental performance

1. Thermal Shock

2. Temperature Life

3. Humidity/Temperature Cycling

4....