not sure you'll find too many 50/60Hz auto-transformers made out of ferrite ....for a ferrite autotrans
autotransformer, which knocks the mains down by just 15-20V or so.
let´s say an autotransformer for stepping down 20V from 240V...the 240VAC UK mains. Its bidirectional. Its 5.5kWh rated. The mains comes to it via an autotransformer, which knocks the mains down by just 15-20V or so.
A bucking transformer is really a modified version of an autotransformer. The difference is that only a small part of the winding has to carry the full load current.
"This is probably as close as you can get to the much hoped for (but disallowed by the laws of physics and the taxman) 'something for nothing'."My source is Rod Elliott's website, where he goes into depth about construction and operation of the autotransformer. He tells how it can easily transition to a bucking transformer (or else boost transformer), with the adjustment of a few specs. He states:
Bucking Xfmrs
Bucking Transformers - What they do, how they do it, and how to determine the proper transformer to usesound-au.com
(His site specifically asks that his home page be linked):
sound-au.com
Several schematics are in the article. These gave me a clearer picture how to simulate an autoformer (starting with the ordinary transformer model). It brought out the fact that the unit can get by with a power rating at a fraction of the overall Watt throughput (per Klaus post #11).
If you start with an isolated transformer with isolated windings of different guage wire and connect them in series , to make buck/boost type auto-transformers, they are no longer isolated and the high load current only passes thru the 2ndary non-isolated winding.bucking transformers have isolated secondaries, separate to auto-transformers which do not ....
the iso sec can be placed in phase with the mains - boosting - or antiphase - bucking ....
Perhaps it's semantics or my lack of experience on this application, but once the isolated secondary is connected, it's no longer isolated so primary share currents from mutual coupling of secondary current and flux. I tried a simulation but could not show a significant primary current reduction at 2:1 , perhaps too much.a buck or boosting Tx has its isolated secondary connected in series with the mains, in phase or anti phase, the primary, is of course driven from the mains.
--- Updated ---
Fig.4 in Brads link with the explanation given as the "proper" way is a little misleading, as it removes the solid output of the LV wdg, and allows the voltage to be pulled down by the load, which is less the case for a true bucking connection.
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?