Isolation transformer isolates, electrical connection, for computer, TV, CRO etc. equipments. It stops the primary (source) side voltage surge (switching,lighting etc.) to transfer on secondary side ,which may harmful and damage the equipment. Metalic cover earthed through earth pin avoids shock hezard. Neutral is connected to earth, if earth pin is not there.

But if there is a surge on Primary, then it will get reflected on to secondary also na ... !!! if its a step down transformer, then the magnitude will be reduced. but people use 1:1 turns ration na.. !!!

Transient high voltage surge are short duration surge and due to time constant(T), it will not reflect immediately on secondary side!!!!!!!!!!!!!!. Read my paper," CT performance!!!!!!!!!!!!!!." Modern plug (extension) uses electronic surge supressor, avoids the use of isolating transformer.

Ohh ok sir. Thanks for sharing the information.

What is the Time Constant dependant on ? Is it the Resistance and the Inductance of the Primary? and if we dont use an IT, will the human get shock while handling the Probes ? Can i download the paper you mentioned from Research Gate ?

Sir, but even if the surge gets reflected on the secondary after a time delay, will it not affect the Oscilloscope ?

T=L/R for inductive, and 1/RC for capacitive circuit. Higher harmonics will suppress, hence amplitude of surge, will not be damaging, for equipment. I can send copy of my any publication, if I am having your address.

Dear Bhupendra Sir,

Thanks for your reply sir. My email id is [email protected]. I would be very glad to read your paper sir.

Thank you

Vamsi Kaushik

Dear Holger Sir,

Thanks for your very nice reply sir. Thanks for taking out time for giving a very broad reply. Thank you very much ..

Regards:

Vamsi Kaushik