List of transformer size types/output powers

[Behemot]

Since we run to this every time and I guess I am not the only one who does not remember it all the time, I have been thinking about some list of transformer core sizes and their corresponding maximum power output. Consider normal ATX power supply with combined output on all rails. Would be good to type both average and maximum power. Think about average crappy PSU (efficiency wise, lets say it has input transistors and capacitors of enough capacity for the power).

So, some sizes I can think off…

EI-28 - 200 W continuous, 250 W peak
EI-30
EI-33 - 250 W continuous, 300 W max
EI-35 - 350 W continuous, 400 W max
EI-39 - 500 W continuous (?)
EI-40

[goodpsusearch]

Re: List of transformer size types/output powers

EI-33 ~250W max, 300W peak

EI-35 ~300-350W normal, 400W max

[c_hegge]

Re: List of transformer size types/output powers

ERL-28 - 200W Continuous, 250W Peak
ERL-39 - Never been able to max one out before (Most PSUs I run into with them seem to feature OPP), but they seem to be able to manage at least 500W continuously

[Behemot]

Re: List of transformer size types/output powers

Thanks. What bout the EI-40? Run into it in one generic PSU. It is somewhat thick, but lower on the other hand. I think it is arround 300-400 W level, are you familiar with this one?

[Behemot]

Re: List of transformer size types/output powers

I'll just add it states 4 mH. Does the numbering have something in common with their inductance, e.g. EI-33 having 3,3 mH and so on?

[Th3_uN1Qu3]

Re: List of transformer size types/output powers

Inductance has to do with the number of turns, the core Al value and the air gap (if any, not used in half bridge, and usually not used in single or double forward either, but could be). It's got nothing to do with the core size, although, for a given number of turns, a bigger core will yield higher inductance. Hence for bigger cores you can use less turns.

[Behemot]

Re: List of transformer size types/output powers

Isn't there some magnetic inductance flow through the core? Considering this the core size should matter, now? Because of all those saturation things and so.

[Pentium4]

Re: List of transformer size types/output powers

When you say for instance, "350W continuous" is that usable watts or including inefficiency?

[Behemot]

Re: List of transformer size types/output powers

Output from the PSU as a whole. Sure, it includes some 50 W for heat only than…

[Pentium4]

Re: List of transformer size types/output powers

Just curious

[budm]

Re: List of transformer size types/output powers

Switching frequency comes into play also.

[Behemot]

Re: List of transformer size types/output powers

Man don't make it too difficult for once, can you? Fifty thousand things come into play, this way we will have shit again, not list. As I said lets talk about average PSU, lets say 2003/2005 driven. You usually dont find much over 60 kHz in there.

[Th3_uN1Qu3]

Re: List of transformer size types/output powers

Isn't there some magnetic inductance flow through the core? Considering this the core size should matter, now? Because of all those saturation things and so.

Inductance is an electrical property, like resistance and capacitance. It does not "flow". You meant magnetic flux, or "induction" which is noted B and measured in Teslas. Yes, you do get a magnetic field. Saturation flux (Bsat) is given by core size and geometry (more specifically: effective area, noted Ae), number of turns of primary winding and how much voltage is applied to it, for how long.

Inductance is just a byproduct of the number of turns and the core Al value. If you're making an inductor, you would still need to respect the number of turns per volt so that the core does not saturate - then, if the inductance ends up too high with the required number of turns, you use an air gap to bring it back down.

As I said lets talk about average PSU, lets say 2003/2005 driven. You usually dont find much over 60 kHz in there.

Yes, because the bipolar transistors used work best at <70kHz. Also the cores become less efficient over that - the number of primary turns does not decrease, because the material saturates earlier. They work best at 30 to 50kHz.

[Behemot]

Re: List of transformer size types/output powers

Inductance is an electrical property, like resistance and capacitance. It does not "flow". You meant magnetic flux, or "induction" which is noted B and measured in Teslas. Yes, you do get a magnetic field. Saturation flux (Bsat) is given by core size and geometry (more specifically: effective area, noted Ae), number of turns of primary winding and how much voltage is applied to it, for how long.

Ah, didn't know the terms in english, thanks

[Behemot]

Re: List of transformer size types/output powers

Is there really any difference between EI- and ERL- cores? Mean transfered power wise.