IR2153 smps with short circuit protection.

KX36

New member
I did the transient analysis of this same simulation to show the difference the optimised snubber makes.



The asc file is attached.
 

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AndrewT

New member
................... estimated irf740 will go 500-600 watts and irfp460 will be more maybe 1kw. to reach this we must use at least etd49 core with multi strand wire awg 22-29. :D.

for standard winding i`ve use 12 + 12 for the primary with 6 strand AWG29.
because this smps is no feedback and always run at 50% duty cycle, the output voltage estimated about 6vdc per turn.
so if we wound 6 turn with AWG29 ( i use 8 strand)
...........................
for multi-parallel turns:
are the separate wires for each Turn insulated from each other as in enameled copper wire.
Or
are the separate wires for each Turn just plain copper with an overall insulating jacket?
Or
are they Litz wire?
 

borysgo2

New member
for multi-parallel turns:
are the separate wires for each Turn insulated from each other as in enameled copper wire.
Or
are the separate wires for each Turn just plain copper with an overall insulating jacket?
Or
are they Litz wire?

Please check the ''skin'' wire diameter (eg, for 70kHz it is equal to 0.5mm, for 100kHz it is 0.4mm), the wires are standard copper wires insulated with ''clear paint'' (I do not know proper English word) used for trafos,inductors, ect. Calculate amount of mulit parallel wire pack in the way that they will fill in whole center pole of transformer. The wires diameter should be small enough to do not go over ''skin diameter'' and amount of copper in winding suffictient enough to cover approx 5-6A per mm^2.
I do not know If you have it but there is small help in post no 31:

http://www.diysmps.com/forums/showt...programs-for-transformers-and-inductors/page4
 

KX36

New member
It's called enameled copper wire in English. Skin depth equation for copper wire is roughly 76mm/(frequency^0.5) which is 0.287mm at 70kHz or 0.24mm at 100 kHz. The radius should be less than this to reduce skin effect losses, but from what I've read, the diameter less than this to reduce proximity effect losses, which borysgo2 wire size estimate doesn't account for. Also 5A/mm2 is the rule of thumb for bare wire which will be cooled by air convection. for wires packed inside a transformer its more like 2.5-3A/mm2.
 

borysgo2

New member
KX36
Thanks for explenation !
I mean ''skin'' wire diameter with skin depth 0.24mm at 100Hz the wire is roughly 0.5mm (am I correct ?).
Could you tell me the 2.5-3A/mm2 it is RMS value of current ?

THX
 

AndrewT

New member
KX36
Thanks for explenation !
I mean ''skin'' wire diameter with skin depth 0.24mm at 100Hz the wire is roughly 0.5mm (am I correct ?).
Could you tell me the 2.5-3A/mm2 it is RMS value of current ?

THX
It looks from the replies that Litz wire is not required.
That a bundle of enamelled copper wire is sufficient.

Skin thickness works from the outside edge of the conductor towards the middle.
If skin depth is 0.3mm, then that tells us that the impedance at 0.3mm from the surface is effectively higher than the impedance at the surface. This forces the current to crowd into the surface layer and progressively less in the deeper part of the conductor.
By the time the diameter equals twice the skin depth there is significantly less current in the middle than at the surface.
This would indicate that a diameter than twice the skin depth is appropriate to maximise the use of the copper.

So the question becomes:
What is the maximum copper wire diameter relative to skin depth at the frequency being used?
1times skin depth or 1.5times or 1.9times.

Or is the increase in impedance at skin depth so small that a diameter greater than twice the skin depth is usable without significantly increased heating of the surface layers?

I have seen 3A/mm² to 6A/mm² for low frequency transformers.
I have seen 5A/mm² to 15A/mm² for small high frequency transformers.

They explained this high current density by using the very low distances that the heat needs to travel to get to the cooling air stream.
I somehow doubt anything like 15A/mm² is usable, but for a few turns of very thin wire, where the thermal conductance to the air stream is very high and high temperature enamel is used then very much more than 3A/mm² could be used without overheating.

I have both 0.3mm and 0.4mm diameter 130°C enamelled copper to experiment with.

Thanks for your answers.
 
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KX36

New member
borysgo2,

Bearing in mind I only know what I've read about this, as I'm unable to really measure what's going on inside a wire in a transformer...

How thick a wire you use depends on how much difference between DC and AC resistance you design for. Theoretically, as long as the radius of the wire is less than the skin depth (and therefore the diameter is less than twice the skin depth), Rdc=Rac. The cross sectional area used at a given frequency might be less than at DC if the wire's more than twice the skin depth in diameter, and this decrerased area equates to a higher resistance and therefore a higher copper loss at that frequency, but depending on how much copper loss you can tolerate you might calculate that it's still OK. In an inductor in continous current mode such as the buck inductor for example, the DC current is greater than the AC current, so the AC resistance can be proportionally larger than the DC resistance and thicker wire used for a given frequency.

Proximity effect is where things get a bit different. In order to induce a current in a wire, a magnetic field has to be able to reach it. If it can only penetrate half way though a wire, it will induce a current only in that half of the wire. For a single layer of wire, that's not much of a problem. For multiple layers however, you might get the effect that the current running on the near side of a wire is partially opposed on the far side of the wire and you get little magnetic circuits set up between the layers. The net current through both will be as expected as the whole system is in equilibrium, but the copper loss will be greater than expected (e.g. net current through a wire is 2A, but 3A run through on one side in one direction, 1A in the side in the other other direction. The net current is still 2A, but the resistive loss is as if 4A runs through it). The more layers used, the exponentially worse it gets and you might see that this could potentially equate to a greater loss than simply the skin effect alone. That's why I use wire of the same diameter as the skin depth, but it's still a pretty arbitrary thickness mainly designed for my own peace of mind.



Here's an image courtesy of wikipedia of one method of calculating Rac/Rdc ratio for various thicknesses of square wire (h) compared to the skin depth (delta). You can see that the skin effect alone is shown in the light blue "1 layer" line. The proximity effect is shown in all the other lines. It looks to me like where the gradient of the line is twice as steep, that's where the proximity effect is dominant and where it's half as steep is where the skin effect is dominant. If you simply look up a vertical line down the centre of the plot at h/d=1 and look up how many layers of wire you have, you'll probably see that Rac/Rdc is quite high (by eye, at 5 layers, Rac/Rdc=4, at 10 layers, Rac/Rdc=16). Now if you look up h/d=0.5, you see for 10 layers, Rac/Rdc<2. You'd probably want to use this graph to match the wire thickness to the number of layers for Rac/Rdc<2or3

Yes, amps RMS are what's important since we're trying to calculate power dissipation. This would generally be significantly less than the peak current.
 
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res_smps

New member
hi all,

it is my first post in diysmps
after reading and learning IR2153 based smps from this forum, especialy thread from norazmi(this thread) and microsim, i built my smps.
many thanks for norazmi and microsim

it use IR2153D
i use cheap refurbished 2SK3528 from fuji electric
the core is EER53, the dimension match with datasheet but other core parameter i dont know, i think it's from china, i got it from local shop only for 3,2 USD (35ribu rupiah)


the primary transformer : 11+11 turn (4x0.5mm wire)
secondary : 5+5 turn (4x0.8mm) = 35-36volt
aux : 3 turn (1x0.5mm)

i have tested using dummy load connected from positive rail to ground and got approximately 400W (32v x 12,5 ampere)
dummy load is limited to 48 volt(it is electronic dummy load, i see lot off TO3 transistor there) so i cannot push it hard using 70volt(plus and minus rail)

i don't have real device (amplifier) that required high power so i am quite happy for 400W for now
and why i choose EER53 because I only found this ungapped core on the shop, all the other core has a gap

any advice is welcome

regards,
resma
 

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MicrosiM

Administrator
Staff member
hi all,

it is my first post in diysmps
after reading and learning IR2153 based smps from this forum, especialy thread from norazmi(this thread) and microsim, i built my smps.
many thanks for norazmi and microsim

it use IR2153D
i use cheap refurbished 2SK3528 from fuji electric
the core is EER53, the dimension match with datasheet but other core parameter i dont know, i think it's from china, i got it from local shop only for 3,2 USD (35ribu rupiah)


the primary transformer : 11+11 turn (4x0.5mm wire)
secondary : 5+5 turn (4x0.8mm) = 35-36volt
aux : 3 turn (1x0.5mm)

i have tested using dummy load connected from positive rail to ground and got approximately 400W (32v x 12,5 ampere)
dummy load is limited to 48 volt(it is electronic dummy load, i see lot off TO3 transistor there) so i cannot push it hard using 70volt(plus and minus rail)

i don't have real device (amplifier) that required high power so i am quite happy for 400W for now
and why i choose EER53 because I only found this ungapped core on the shop, all the other core has a gap

any advice is welcome

regards,
resma


Very good, and nice PCB.

It looks you have used another circuit?

Regards
 

res_smps

New member
Very good, and nice PCB.

It looks you have used another circuit?

Regards

may be, I learned a lot about IR2153 from this forum (especially from your and norazmi's posts) then I tried to combine the existing circuit i found here, from net and with what is in my head

formerly i have build regulated smps based on tl494+IR2110 but it generate audible noise on power amp and on transformer itself.
and then i try unregulated smps based on IR2153 and I impressed with the result
 

bud17

New member
That's geat res_smp.

I have core EER40D with no gap.
If my target +-42VDC 10A, is it possible?

Thankyou.
 

res_smps

New member
That's geat res_smp.

I have core EER40D with no gap.
If my target +-42VDC 10A, is it possible?

Thankyou.
+-42VDC, 10A is 840W?
sorry i cannot answer your question because i don't have experience playing smps more than 400W. may be some people here can help you
or may be you can input the dimension on ExcelentIT software then calculate it
from my expperience with chinese EER53, after input dimension then select material with flux density 0,1 to get primary turn, with higher flux (less number of turn) my trafo overheat
 

demykiko

Member

demykiko

Member
Stewin, nice work!

Notes:

Your schematic is missing the output filter coils.
In my case I used a 2 x 22 uH. Don’t forget!
You can use a EI33 from an old PC smps. Should have a 0,1 mm gap. ( pieces of paper sheet).

TR1 should be 1:50 turns on iron powder core. (Small green core from a old computer board).

The Vaux. winding should be in the right phase otherwise Q1 will get hot really fast.
(Just invert the wires on the circuit if Q1 is get hot)

You can not extract 1Kw from the IRF740 maybe 700 W in a better case!
Better if you use the IRF460LC.

Give me a little time to recalculate the right number of turns for your ETD44.

Regards

Marcos Bettecher

Hi Bettecher,

Is this core in the picture is what exactly the green powdered iron core form old atx psu you use as current sense transfo?

green powdered iron core.jpg

Thanks friend and regards,

demykiko
 

jchspb

New member
Hello Friends Good Afternoon!

I followed the 40 pages of this forum and I could see that all employees are very helpful.

This is my first post.

I have some SMPS made with ir2153 but none has protection! What causes me great problems. Blast several mosfets for my carelessness to clean my workbench.

Then I found this forum. But several people have posted many models of SMPS and as my English is not so good (I'm from Brazil) I was lost in which model I can trust to do my final SMPS with short circuit protections and over-current.

I know a bit of electronics but do not know how you develop.

So if they can send the complete electric scheme and PDF files for me to do my own SMPS I'd appreciate it.

Many thanks to everyone who helped here.

GREETINGS
JC
 

jchspb

New member
Hello Friends Good Afternoon!

I followed the 40 pages of this forum and I could see that all employees are very helpful.

This is my first post.

I have some SMPS made with ir2153 but none has protection! What causes me great problems. Blast several mosfets for my carelessness to clean my workbench.

Then I found this forum. But several people have posted many models of SMPS and as my English is not so good (I'm from Brazil) I was lost in which model I can trust to do my final SMPS with short circuit protections and over-current.

I know a bit of electronics but do not know how you develop.

So if they can send the complete electric scheme and PDF files for me to do my own SMPS I'd appreciate it.

Many thanks to everyone who helped here.

GREETINGS
JC
 
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