Isolation Transformer often has symmetrical winding which is used to decouple 2 circuits. It incorporates a full metallic shielding (copper /aluminum) between primary & secondary winding
Isolation Transformers are being used to protect electronic & sensitive creative equipment such as computer & peripherals medical instruments, digital machines & CNC M/C from the Excessive line voltage transient, spikes/surges produced in the system. Apart from this, the isolation Transformer also obstructs those disturbances that are generated by the noisy equipment from being injected into the power line i.e. it filters common-mode noise usually an attenuation of approx. 30 DB.
In a Shielded transformer, 4 low impedance paths Exist for noises to pass to secondary & vice versa. These paths are:
– The high value of coupling capacitance.
– Maximum leakage of a magnetic field.
– Leakage current
– Static transformers of electric noise.
The multiple shielding techniques employed in isolation Transformers reduce the interwinding capacitance below to 0.005 Pico farad & increase D.C Isolation to over 1000 M ohms.
Application of Isolation Transformer
• Protection of microprocessor-based Machines from Damage & data loss
• Where the ground of equipment cannot be earthen
• When no current leakage is permitted in equipment
• When protection is needed against high-frequency line losses & strong surges.