transformer core questions

neduet

1.If we increasing load on secondary of transformer core loss is same or not ?

2.what is the most common lamination thickness of transformer core?

3.some kind a paper we used in winding for insulation what is the name of this material?

ernestpworrel

In number one, are you asking about the loss in the core or the total circuit? The only way the loss in the core is going to increase is if you increase windings in the secondary.

The Electrician

1. Increasing load on the secondary will increase the current in the primary. This increase will cause increased I*R loss in the primary, which will decrease the volt-seconds seen by the core. Since the flux in the core is proportional to the volt-seconds applied by the primary, the core flux will decrease, resulting in less core loss.

2. The most common lamination thickness is .014 inches.

3. The most common modern material is nomex, a synthetic paper.
http://en.wikipedia.org/wiki/Nomex

Bob S

For a conventional power transformer operating at 50 or 60 Hz, the core (magnetization in laminations) loss can increase only when

a) The primary voltage is increased (don't use a 120 Vac transformer on 220 Vac)

b) the primary frequency is decreased (Don't use a 60 Hz transformer on 50 Hz unless the mfgr states 50/60 Hz)

c) the number of primary turns is decreased (decreases inductance).

The core loss is determined entirely by the design of the transformer as an inductance w/o a secondary winding. The core probably goes up to ~1.4 Tesla peak; any increase will significantly increase losses.
Bob S