Look Who it Was Random video

Quickly guess the available power of a transformer (see description)

566 views · Published 30 July 2016 · 0:43 · Indexed 23 September 2026

Channel: Alexander Hartdegen · 2016 · Science & Technology

Watch on YouTube

Quickly guess the available power of a transformer
There is nothing theoretical in this method. Depending on the nature of the materials, the power factor at rest and at work can vary very significantly.
On some small transformers "boosted" increases consumption at rest in order to overcome a lack of power by increasing the available magnetic field, a reactor lower face the call to secondary current. In these transformers, the factor is not 8.5, but may be between 2 and 5.
On toroidal transformers, the efficiency is better, so the standby current is often less than that calculated on the video.
A switching transformer according to quality workmanship, the standby current can indicate a power up to 9.5 times less than the total power.
Losses by Joule effect, induction of a transformer are not negligible. They are causing noticeable snoring (at least at rest) and heating thereof.
Losses in a transformer normal EI structure are of the order of 15%.
The calculation by multiplying the power to rest by an approximate figure who has no technical value comes from a usual practice that wants to be a fact: the power output of a transformer is often a multiple of recurring revenue power standby.
This figure is roughly recurring 10. But if one removes the 15% loss by Joule effect, it simply falls to 8.5.

More from this channel