1. Ir2110 Application

Diysmps > diysmps! > diysmps > SG3525 IR2110 50Khz 900W SMPS Question. Unfortunately, I can't load it from work anymore but, assuming its the right file. File: 700w-800w-900w-smps-sg3525-ir2110-pcb Download >Add to. Power Supply Circuit SG3525 IR2110 700 switching power pcb SG3525 smps ir2110 smps.

Hello everyone, I made a 50Khz SMPS using the schematic I have attached to my message. I built it using the exact same parts written in the schematic. The only difference is that I adjusted the circuit for +36/-36 volts.

So, I used a 36v zener and as for turns ratio, (Primary 26 turns of 1.7mm ) and (Secondary 2X4 turns of.7mmX5) are my winding. (ExcellentIT calculations) I expected everything to run smoothly but after running it, all I get in the secondary output is +/- 2 volts!!

Also the transformer makes an unpleasant noise. What would you suggest me to do? Maybe zenner diodes put reverted? I checked every single part one by one, four or five times. Every thing was correct. So, I recalculated the transformer design and did a new winding.

It's a 50Khz half bridge smps with the 300 volts of input voltage. The Rds(on) of IXFH32N50 is.16 ohm. This SMPS is capable of delivering 864W of power when ETD59 core is used.

Ir2110 Application

The primary is 26 turns and secondary is 4 turns X2. I have regulated 12 volts for SG3525 and IR2110 supply. Diodes I have used for the secondary bridge are BYV79-200 (200v 14A 30ns ultra fast rectifier) Today I noticed that the HISS (saturation noise) is still there even if I connect a load to the outputs. I also tried replacing the 36v zener diode with other voltages.

Higher and lower! But nothing changed. I still have only +/-2 volts in outputs. I appreciate your help and attention.

Your feedback and compensation circuits don't looks right but I'm not entirely sure that's your problem. Normally even if it's an unstable feedback loop that oscillates, it will oscillate around the right DC point. This goes for ressmps too, your simulation is oscillating, presumably from an unstable feedback loop.

I'd recommend putting a class Y2 capacitor from primary to secondary ground for starters. That can eliminate one source of nasty transformer hiss, especially if the hiss changes when you probe it with the scope. I would say if possible, next test it with a fixed duty cycle to see if taking the feedback loop out of the equation makes a difference. Then work on the feedback. The error amp in the SG3525 is not a transconductance amp, its your average everyday simple voltage feedback opamp and so it is compensated with an RC network from the comp pin to the inverting input, not to ground. What you're doing there is putting a heavy capacitive load on an open loop opamp so it's no wonder it doesn't work.

SG3525 is a voltage mode controller, which is right for the half-bridge topology, but typically requires type III compensation which you don't have. SG5325 and IR2110 do make a good combination for an offline regulated half bridge, you don't need to use a 'dedicated half bridge driver' as DjLeco said. The optocoupler complicates this as it introduces an extra pole.

Bias it with a relatively high optotransistor current to increase the frequency of this pole out of the way (above the loop crossover frequency). Free hd bollywood movie download. If I were doing this, I'd use a secondary side TL431 as the error amplifier with its own linearly regulated aux supply so that I could put the type III compensation network there, tie the SG3525's internal opamp so that its output is in cutoff and input the feedback directly to the comp pin.

If you do this, I think you want the optocoupler output to be common-collector. This would be similar to ressmps's 'red circle' schematic assuming he tied the opamp inputs to the correct rails to cut off its output, but C6 there is not a good way to compensate the loop. It just reduces the frequency of the optocoupler pole. If it reduced it well below the LC double pole from the plant that might work as type I compensation but a loop with such low bandwidth would have very poor transient response. If you do use the internal opamp as well the optotransistor would be common-emitter as you have it but there's rarely a good reason to use it in an isolated supply.

Here's a brilliant guide to designing TL431/opto isolated feedback. Unfortunately, I can't load it from work anymore but, assuming its the right file, somewhere in there is a type III compensation design guide with a zener regulated secondary aux supply. Ressmps, I'd advise getting a behavioral model of your secondary side working as a buck converter first with ideal opamps, switches, diodes and latches, then add the transformer, then add the isolation. You can derive a linear model of the buck converter to stabilise it with equations in voltage sources etc and then when you add the transformer, add it in as a turns ratio in the equations, or you can derive a Bode plot of the plant by hand on paper with the equatrions, it's not complicated.

Remember to include the ESR of the output cap and any load resistance. SPICE can be a d.o.g (seriously, that's censored on this forum?) for these switching power supplies, so I'd say in your transient simulation command, add a max timestep well below your switching period and add 'uic' on the end of the line. I once spent a week chasing down oscillation that was simply the timestep aliasing on the switching period. Thank you guys. Your answers were so informative. Last night before changing the feedback circuitry, I noticed that the output coils were 47uH instead of 20!

So I replaced them and output voltage came up. (Don't trust Chinese parts! Even a simple coil!!) The transformer HISS decreased drastically and with a load connected to outputs, it disappears completely. Now, the negative rail is exactly -36 but although the transformer winding is symmetrical, the positive rail is 10 volts lower. It's around 26 volts!

I replaced the rectifier diodes and checked the secondary 63V 10000uf caps of + rail but they weren't the cause. Should I still change the feedback circuit? Thank you guys. Your answers were so informative.

Last night before changing the feedback circuitry, I noticed that the output coils were 47uH instead of 20! So I replaced them and output voltage came up. (Don't trust Chinese parts! Even a simple coil!!) The transformer HISS decreased drastically and with a load connected to outputs, it disappears completely.

Now, the negative rail is exactly -36 but although the transformer winding is symmetrical, the positive rail is 10 volts lower. It's around 26 volts! I replaced the rectifier diodes and checked the secondary 63V 10000uf caps of + rail but they weren't the cause. Should I still change the feedback circuit? Try swapping inductor connection sorry i can not upload a picture now,maybe tomorrow. I was thinking if the voltage difference between two rails is derived from the unsymmetrical transformer winding, so reversing its output would reverse the voltages and i'll have +36 and -26 volts.

I did this but nothing changed. I still have -36 and +26. Another thing I did was monitoring the negative rail instead of positive one. So I connected the optoisolator to negative rail. Once again it did not affect the outputs. The way I wound the transformer was like this: (according to ExcellentIT calculations) 1- winding 12 turns of primary (.6mm x3) 2- winding both 4 turns of secondaries together (.6mm x4). Instead of winding 4 turns, bringing the center tap out and winding another 4 turns, I decided to wind both of secondaries together in order to keep them symmetrical as much as I can.

For doing this I plied the (4 string) wire, then I connected its center to one of the core pins as the center tap, and wound four turns and connected it's two end to the core pins. I'm a bit doubty about the winding strategy! Could it be the problem? Correct me if I'm wrong here, but the way you say that you wound your secondary, it seems to me that the two secondary windings are in parallel instead of in series. I've confused myself thinking about this, but if I'm understanding your winding configuration properly, your center tap is grounded as it should be. When the primary current swings positive, both secondary end-taps are going positive, then when the primary swings negative, both secondary taps are swinging negative. The end-taps on the secondary are supposed to swing in opposite polarities in reference to the grounded center tap.

This could be causing the HISS and abnormal output voltage due to core saturation. Correct me if I'm wrong here, but the way you say that you wound your secondary, it seems to me that the two secondary windings are in parallel instead of in series. I've confused myself thinking about this, but if I'm understanding your winding configuration properly, your center tap is grounded as it should be.

When the primary current swings positive, both secondary end-taps are going positive, then when the primary swings negative, both secondary taps are swinging negative. The end-taps on the secondary are supposed to swing in opposite polarities in reference to the grounded center tap. This could be causing the HISS and abnormal output voltage due to core saturation. The dual secondary winding are in series.

Just like showed in the attached picture. I finally got the correct and precise voltages out of my SMPS.

Thank you guys for helping me. My mistake was the way I had wound the main transformer. Thanks to the ressmps guides I rewound it in the correct manner. Those who want to make a smps with two or more output voltages must do the winding of main transformer very precise and evenly. It is so important to take your time for a precise, clean and neat winding and never wind two rails together.

I'll install the heat sink and put it under load for the final testing and will definitely report the results. I finally got the correct and precise voltages out of my SMPS.

Thank you guys for helping me. My mistake was the way I had wound the main transformer.

Thanks to the ressmps guides I rewound it in the correct manner. Those who want to make a smps with two or more output voltages must do the winding of main transformer very precise and evenly. It is so important to take your time for a precise, clean and neat winding and never wind two rails together. I'll install the heat sink and put it under load for the final testing and will definitely report the results. Hi kooroshi60, any update from your project? I am happy to hear good news from you.

Hi KX36 maybe my simulation is not good enough, i just want to show that one way to overcome the noise(vibration) of the transformer is by eliminating pulse skipping I've never been able to successfully use an internal error amplifier (SG3525 or TL494) without causing pulse skipping, I need to learn more You need to be careful with terminology here. There is a feature of some SMPS controller ICs that they turn themselves on and off to improve efficiency at low loads. There are a few names for that that involve the words 'burst' and 'skipping'. What you have is oscillation, pure and simple, from an unstable feedback loop. I'd suggest you start your learning with small signal analysis of these converters and compensation techniques. Sorry to go off topic from the original post there.

Hi i'm going to start my first audio smps.i want use it for my Nmos200: +/-40v 5A 2X200W@2Ohm - 600W max power consumption = +/-40v 7.5A per rail i was read this thread: ) now i'm confused i don't know which circuit is suitable for me! IR2153 or IR2110+SG3525 it's because at first, ludo built the ir2153 based circuit but in newer version, he was build 3525+2110 based circuit and result was more reliable. Can anyone help me about this issues? There is the latest version of Ludo's IR2110+SG3525 based circuit, please tell me about it, it's OK?

Thanks MicrosiM But i think that schematic have a lot of problems: - the output voltage not adjustable, what you think? - the Snubber circuit behind the mosfets (5R6+330pf), it's a copy from QSC PLX1802 Schematic! It's ok for this circuit? That circuit use IGBT and worked in resonant mode. what about current sense inductor?

Please tell me about winding and core specs. main transformer was calculated based on excel file and you can download 80V design on the attachment. I got minimum voltage of the 220v line around 200v, then 200v X 1.41= 282v/2 = 140v, you can see another parameters on excel file. on current limit circuit, how much is the P1? - the output inductor maybe in wrong place, it's must be after the rectifier, also i don't know the good specs for that. I'm sorry for asking too meny questions.

Thanks MicrosiM But i think that schematic have a lot of problems: - the output voltage not adjustable, what you think? For audio application, you dont need regulated SMPS.

the Snubber circuit behind the mosfets (5R6+330pf), it's a copy from QSC PLX1802 Schematic! It's ok for this circuit? That circuit use IGBT and worked in resonant mode.

Your snubbers are OK, whats the problem if you take info from other designs? - what about current sense inductor? Please tell me about winding and core specs.

Current sensor will be try and error at the first, that value is just OK as a start - main transformer was calculated based on excel file and you can download 80V design on the attachment. I got minimum voltage of the 220v line around 200v, then 200v X 1.41= 282v/2 = 140v, you can see another parameters on excel file. If you have followed the formula, your transformer will work.

on current limit circuit, how much is the P1? P1 value, start with 50K - the output inductor maybe in wrong place, it's must be after the rectifier, also i don't know the good specs for that. No need for those output inductors, since its not a REGULATED SMPS I'm sorry for asking too meny questions -. Calculations for transformer is OK Dont forget Making this SMPS from scratch, like in your case, will need things to be done right I advice you to ask about every thing. Dont forget Making this SMPS from scratch, like in your case, will need things to be done right I advice you to ask about every thing.

Don't worry it's not my first 220v smps, i have made 100w 18v smps about 1 years ago, but design based on pi-expert. I'm also download very useful pdf files from this forum to learning about construction, winding, calculation and many other things, thank you for supporting 'DIYSMPS' what's your opinion about 16v 0.5A auxiliary smps?

I want to design and replace it for pcb transformer. Anyway, i think designing this PCB will be difficult i'm also going to buy Rigol 100mhz Scope and X100 Probe, also isolation transformer - the schematic at version 0.1 also available, but i'm not grantee the operation of this circuit before testing it.