Can anyone tell me if there is a usable relationship between the size/mass of a transformer core and its low end frequency response?
For example, would a 120V to 12V step down transformer with a higher VA rating be more efficent than a lower one in passing frequencies below 60Hz?
Richard
"Richard Osbourne"
** It is really *very* simple.A transformer rated for certain input voltage at 60 Hz, will operate with the same efficiency ( and primary magnetising current) if the voltage and frequency are scaled together.
Eg. 120 volts @ 60 Hz.
The size (VA) of the core has no effect on this characteristic.
....... Phil
As usual, Phil is sort of right, but misses two points of some practical importance, which are that the inductance of a transformer is more or less proprtional to its size, and that in order to get an adequate inductance out of a small core you have to put on lots of turns of very fine wire, where the constant thickness of the insulating enamel occupies a disproportionate amount of the winding window.
These two effects conspire to make small transformers disproportionately lossy at low frequencies - check out the difference in regulation between a 6VA and a 12VA mains transformer.
For higher VA ratings, the (constant) thickness of the enamel layer on the thicker wire you end up using ceases to eat up any significant proportion of your winding window, and size becomes progressively less important.
It all depends on whether you are winding, or just buying.
A larger core allows a lower frequency primary to be wound on it. If just buying, go for a a 240V/60Hz transformer, which will work ok at 120V/30Hz.
= a F****IT
** Small mains transformers have more inductance.The proportionality is therefore inverse.
** Of zero relevance to the OP's Q.** Why does the autistic cretin keep slandering his home town like this ?
.......... Phil
"Tony Williams"
** Funny how microphone level transformers are tiny and work fine down to 20 Hz or less........... Phil
Right, Phil. That has absolutely nothing to do with power transformers. You want to minimize both the iron, and the copper losses to keep the cost down. BTW, how well do your microphone transformers work at 120 VAC?
They need more inductance, so the number of turns required grows in more than linear inverse proportion to their size.
If you want to look at it that way.
In Phil's ideosyncratic opinion.
Even funnier that Phil is ignorant enough to see a paradox there.
They work at microwatt levels and often have exotic cores, permalloy and such.
It's interesting that XLR connectors are rated at 1500 volts, 16 amps. How loud might that be?
John
= An imbecile
** Self referencing, autistic drivel - like all Da Slow Man's idiot posts. ** Poor Nijmegan........... Phil
"John Larkin" "Tony Williams"
** A mic level tranny works at the tens of milliwatts level - up to several volts into a 250 ohm load at 30 Hz.The point is that low frequency capability is not directly related to core size until a VA rating is specified.
** Pluck that voltage figure out your arse ?....... Phil
Is "audio expert" a logical construct?
John
The clown hasn't a technical leg to stand on, so he falls back on his formulaic abuse.
" Da Slow Man "
** Thinks " filling factor = frequency response ????Should be put down - like some poor sick animal.
** Nijmegan ought to sue the useless cretin for slandering his home town........... Phil
....... Phil
Yes.
"Robert Baer"
** No........ Phil
Ehhh? I can't hear you!
Those answers translate to "maybe"????
"Robert Baer"
** Just possibly a maybe.......... Phil
Have something to add? Share your thoughts — no account required.
Ask the community — no account required