SMPS Formula

[microsim444]

Hi.

What is the turns ration to get +-100V DC from ETD59. and what is the best frequency to do that. wire size, the winding advice


Input voltage 220V~
Reference Schematic is attached.

what is the formula that can be used to calculate that, any help?

[umut1001]

hi

for 50khz 1kw

primer 14 turn(10x0.65mm wire) , sekonder 2x 14 (8x0.65mmwire)turn

feed back : zener 97v ,resistor 1kohm

[umut1001]

lastest version sch.

[microsim444]

Originally Posted by umut1001

lastest version sch.

Dear,



I will use ETD59, I need 1.5KW ~2KW to power 2x1000W Amplifier.

Do I need to do any thing else? is the 50K frequency will generate that power from the ETD59?

And is that wire a LITZ wire?


THANKS

[Eva]

Originally Posted by umut1001

lastest version sch.

If this is intended to be a regulated supply, the output inductor should be placed after the diodes, not before

If it works with the inductor in the wrong place, the waveforms are likely to be very funny...

This post discusses obtaining cores and calculating inductors, but the B (peak flux density) formula and the core loss formula are valid for transformers too:
Big-t

In a transformer you have to select primary turns so that peak B does not exceed the saturation level of the core material in worst case conditions (highest input voltage, highest duty cycle) and observing that peak B during normal operation results in reasonable core losses (like 4W-6W for an ETD59, but this is just an intuitive estimation based on size). Note that many materials will exhibit lower losses as they get hotter.

Secondary turns are calculated taking into account that in a transformer the same voltage drops in all the turns (at least without load) so turns ratio is just voltage ratio. Voltage ratio for regulated suplies is chosen so that output voltage can be mantained down to the lowest input voltage desired...

[microsim444]

Originally Posted by Eva

If this is intended to be a regulated supply, the output inductor should be placed after the diodes, not before

If it works with the inductor in the wrong place, the waveforms are likely to be very funny...

Eva, first you are always give nice comments and it looks that you have deep experiance.

Why you just for ONE time give a solution? give informations that HELPS solving problems?

Are you in the process of building any new SMPS? 2KW

[Eva]

I think I have given the information that you need many times since I joined the forum 6 years ago. I can repeat it from time to time but not for everyone that asks because this is very time consuming, and everyone wants the things already calculated instead of learning how to do the math themselves.

I'm finishing a long class D project, very complex, with many gadgets, but also extremely efficient, it's doing 1500W music on 4 ohm and I have not yet installed the heatsink (bare TO-220 devices) Next project is SMPS related but quite unconventional (single stage non-isolated AC mains to regulated DC).

[luka]

If you want to make money from it, you need to do it by yourself, why would Eva do this for you? She needs money too you know

[luka]

Originally Posted by Eva

Next project is SMPS related but quite unconventional (single stage non-isolated AC mains to regulated DC).

AC buck converter? or higher DC from AC, like pfc?

[umut1001]

Originally Posted by Eva

If this is intended to be a regulated supply, the output inductor should be placed after the diodes, not before

If it works with the inductor in the wrong place, the waveforms are likely to be very funny...

This post discusses obtaining cores and calculating inductors, but the B (peak flux density) formula and the core loss formula are valid for transformers too:
Big-t

In a transformer you have to select primary turns so that peak B does not exceed the saturation level of the core material in worst case conditions (highest input voltage, highest duty cycle) and observing that peak B during normal operation results in reasonable core losses (like 4W-6W for an ETD59, but this is just an intuitive estimation based on size). Note that many materials will exhibit lower losses as they get hotter.

Secondary turns are calculated taking into account that in a transformer the same voltage drops in all the turns (at least without load) so turns ratio is just voltage ratio. Voltage ratio for regulated suplies is chosen so that output voltage can be mantained down to the lowest input voltage desired...

Yes Eva you are right..I did not have time to correct this mistake Thank you very much for taking care