Audio smps 700w (IR2153)

nazirdigi

New member
hi silvio, thank u for ur reply,
i modified little like a pro board.
 

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Silvio

Well-known member
Hi Nazirdigi, good arrangement. Use current limit board because the other ones are not tested. Make sure that the gate diodes are pointing to the IR2153. I have a mistake in one of the component layout diagrams.

Do not forget to post some pictures of your project.
 

blasphemy000

New member
@Silvio: Hey, just noticed something odd while looking at your circuit board layout. Your 3 dual rectifier diodes are setup kind of strangely. You have 4 diodes(2 packages) rectifying the negative output rail, while you only have 2 diodes(1 package) rectifying the positive output rail. Was this intentional or was this an oversight while designing the layout of the board? With the type of diodes used there isn't a way to evenly split them using only 3 packages, so I'm just curious as to why it was designed this way. Nice project though, very effective.

-Brad
 

Silvio

Well-known member
@ Blasphemy000
The only reason I have 50 of these diodes that I bought in an auction on E-bay and configured a full bridge with them. They are genuine and good diodes. I even used them on the 1000watt smps that I published here but used 4 of them so the bridge will be more balanced and have a full capacity of 16A at 200v.

Regards Silvio
 
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Silvio

Well-known member
audio smps 700 watts

https://imgur.com/a/r32w6

New mod to Audio smps 700w with 2 output diodes instead of 3 and added output capacitance and filtering. It can also fit 14 and 16 pin bobbin for ETD 39
 

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blasphemy000

New member
Ah, I gotcha. I was just curious as to the reason behind it. I've built things where using what I already had led to an interesting design. As long as the functionality is there, that is all that matters. Thank you for the explanation.

-Brad
 

luizcpimenta

New member
Choice of oscillators and protection

The PCB can be adopted to work with a different oscillator as mentioned before due to the oscillator board and protection circuit is mounted on a separate pin header. This is plugged in the socket provided on the pcb. I also made plans to use different protection circuitry using either a Schmitt trigger or driving an SCR gate with both options pulling down pin 3 of the IR2153 to ground. However these type of protection brings out the need to reset by switching off the supply and waiting for the bulk cap to discharge until it can be switched on again. I prepared the prototype pcbs for these but have not been tried yet

Heat sink and cooling

A good heat sink is needed for the fets and output diodes as these are driven quite hard during the peak output. With the heat sink used the smps can handle the power easily if a small fan is included. I made a fan socket available for this reason. In my setup peak power could be held for quite a long time without things getting hot with the fan on. This was placed at the side to cool also the transformer

Auxiliary output.

An auxiliary output of 12v-0-12v is provided capable of around 800mA. This is intended to drive a preamp stage or some protection circuit on an amplifier. I often see the need of a separate output for this reason.

The design voltage of the smps is 46-0-46 peak at 230 volts input. During my tests the output voltage went down to 78volts at 9.4 amps. The input voltage was 227vac with a power output of 730watts. The efficiency of the smps reached 90%.

IF ANYONE IS INTERESTED IN BUILDING THIS SMPS I WILL SEND THE PDF FILE PRIVATELY


View attachment 6150


Good Morning. Can you send me the power scheme of this source?
Thank you.
luizcpimenta@gmail.com
 

steppler

New member
Hello
Please, I have problem with this SMPS

I=4A, U=42V ..... It's OK
I=0,1A, U=80V .... too much without load !!!

Please help me.
 

Silvio

Well-known member
@ Steppler

This is very odd and I don't know what number of turns you wound on the transformer. The voltage that you are experiencing is not normal and also this could not be true especially if you are measuring the voltage with an analogue meter. The meter could not be reading the true voltage due to it being disturbed by EMI form the smps.

Please take some pictures of your setup and upload them. If you have a scope show some waveforms

regards Silvio
 

Silvio

Well-known member
@ Steppler

A quick view of your number of turns shows that the peak voltage is in fact around 42v

Here is my calculation for you.

The nominal input voltage is 220vac so with rectification and smoothing that will rise up to 220 x 1,414 = 311v

The half bridge input voltage of the smps is 311/2 = 155.5vdc (we round off to 155v to keep things simple)

Volts per turn = 155v / turns primary 46 turns = 3.37v

Secondary turns = 13 so 3.37 X 13 = 43 volts on secondary

The turns are correct and the output should be in the region of 42v or so depending on the input voltage

Some considerations

1) The PCB is very neat and very nice layout

2) I cannot see the input current limiter (Thermister) in the input. The input rectifier may blow without it during start up.

3) The gate source resistor are without value these could be either 100 ohms or 100K I think 4.7K-10K will be more appropriate

4) The IR2153 does not have enough current to drive the IRFP460 properly, IRF740 fets will be more appropriate and can handle the current needed comfortably. ( up to 500w to 700w peak)
The output inductors are a bit on the high side though they are not needed due to the smps is running in full duty cycle. Without output inductors there is far less voltage drop when smps is loaded. I think that you will not need more than 6uH. Please also note that output inductors tend to reflect back some spikes to the input wave form. ( I am talking through experience here.)

5) The SMPS does not include a snubber on the primary winding, this is essential if you have output inductors as the wave form tend to have spikes in it.

6) The only protection you have is a fuse on the output. Where is the fuse in the input? This will be the last thing to break the circuit after the fets and IR2153 and possibly the input rectifier bridge has blown off in the event of a short on the output.

7) Where is the 3rd polypropylene capacitor (RED) connected to? Is it before the transformer primary? What is the reason for this? I cannot see it in the schematic.

Lastly if you have a scope please post some pics of the waveform. I believe that the stray voltage that you are experiencing is due to spikes within the wave form. This voltage will quickly go down as soon as you load the SMPS. If you take a look at the pics I posted in the beginning of this tread you will see what is should look like.

Good luck Regards Silvio
 

steppler

New member
Corrected schematic:

SMPS42.jpg

Driver IR2153 and current limiter:

smps08.JPG smps09.jpg smps02.jpg smps03.jpg

Provisional current setting:

smps07.JPG

Transformer pinout:

smps05.jpg smps06.jpg

Out voltage (LED 20mA + 3k9 resistor):

smps01.jpg

TEST:
6x bulb H3 (12V 55W) serial connection ........ measured 43V 3.9A
4x bulb H3 (12V 55W) serial connection ........ measured 49V 3.3A

I don't have oscilloscope. I will measure external.
 

Silvio

Well-known member
@Steppler

1) Is the current limiter working? Do you have the led fitted to see if it is pulling the supply to the IR2153?

2) Change the gate resistors to 22 ohms this will allow a little more current to the gates. Do not go below this value as the IR2153 cannot give more current and will blow. Change gate source resistors form 100k to 10K to help them switch off faster. Change bootstrap capacitor from 0.47uF to 4.7uF. This will give some more juice to the high side gate

3) The 3rd capacitor which is in series with the center of the 47K bleeder resistors is not needed. The voltage is already divided with the other 2 X 1uf capacitors. You can remove it and make a bridge instead

4) Get the current limiter working properly by loading the smps to the desired maximum load then you should turn the preset until you see the current just slightly backing off. The LED that shows the current limit operation will start to illuminate before this happens.

5) When you have the current limiter working properly you can bridge out the output inductors. It is important to follow this procedure otherwise when the secondary capacitors start charging up on start up they present a very low resistance and can blow the switching transistors. The current limiter will operate when the secondary capacitors start charging and limit the current.

Note The output inductors present a lot of resistance and you have a lot of voltage drop with them. You do not need them otherwise make them smaller.

6) Try measuring the input AC voltage and multiply it by root 2 (1.414) The bus voltage on the main bulk capacitor should read a little less than the answer you get for this sum. The half bridge voltage + and center ground should read half of this (around 155 to 160v) if it is higher than this then you will need a snubber across the primary of the transformer

snubber value 220pf X 1kv and 100 ohms 3 watts. resistor in series with the capacitor and soldered across primary of the transformer.

I hope this helps to get rid of the stray voltage you are getting.

Regards Silvio
 
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steppler

New member
OK Silvio.

Current limiter works excellently. It's set to 5A. The warning LED works duly. I set it using a provisional trimmer, and exchange to fixed resistors.

I will try all the changes according to your advice. But mainly!!! ..... I change transistors to IRF740 or 840. IRFP it was a mistake.

I'll let you know.

Thank You.
 

Silvio

Well-known member
@ Steppler

If you change to IRF740 then do not change the bootstrap capacitor leave it at 0.47 uF, gate resistors 27 ohms should also work well. Irf 740 are better than IRF 840 they can handle more power/

Regards Silvio
 

Silvio

Well-known member
@ Steppler

The issue regarding the drive to fets will be ok if IRF740 are fitted instead of !RFP460.

The other problem regarding stray voltage may still have to be sorted out. You might still need to include the snubber across the primary and also remove the output inductors ( you can bridge them temporarily for the time being).

I suggest you try one thing at a time and see how things behave. You are blind folded here without an oscilloscope.

Regards Silvio
 
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