I understand the servo stabilizer, but what does an isolation transformer do that would not already be done in the stabilizer with a filter ? If I have a 2KV @ 220V max load rated stabilizer, what sort rating numbers should a transformer have ?
Sorry for the dumb questions but I am not an engineer.
An isolation transformer is a transformer, often with symmetrical windings, which is used to decouple two circuits. In other words, the input and output are completely isolated. If there is sudden surge at the input end, there will be no change at the output end. If there is sudden demand peak at the output end, the windings at the output end along with capacitors will provide the load without any effect on the input
Isolation transformer with Faraday shield reduces the cumulative leakage current of the isolator and connected equipment to levels below 300 microamps. Some isolation transformers can also remove EMI/RFI noise, utility switching transients, and harmonics generated by other onsite loads such as utility or lightning related surge conditions.
Isolation transformers are used in industrial environments where a large surge in requirement could adversely affect a stabiliser and even burn it. Many manufacturers study the environment and insist on a isolation transformer to protect the stabiliser. It is also used in places such as hospitals, where the power going to very sensitive instruments can never be affected by any transient or noise at the input level.
This may not have much value in the home segment as the transient on the load are never very sudden or of huge value. Even when you increase the volume, good amplifiers restrict the change to be of a gradual degree, particularly when you use a remote control. That is the reason why the volume potentiometers are usually heavy and are stiff. Even if you do twist it hard, internal fail safe mechanism, should come into play.
An UPS does provide a pure sine wave output which is perfect for audio system. Coupled to a external RFI/EMI filter, you will be able to provide clean power to your system.
The capacity of a isolation transformer is usually prescribed as being 20-25% more than the stabiliser. So if you have a 2KVA stabiliser, the isolation transformer should be about 2.4KVA.
Cheers