Hi
Last one, you will see +60 and -60 labels on schema, you can get any voltage you want, just trafo must be corrected
Last one, you will see +60 and -60 labels on schema, you can get any voltage you want, just trafo must be corrected
spec's for supply
It would help if you would specify the power needed for your intended load and what is the intened use as well as input voltage and output voltage and current. +/- 85 volt @ 10 amps requires over 2kW input power and you should consider a full bridge.
chas1
It would help if you would specify the power needed for your intended load and what is the intened use as well as input voltage and output voltage and current. +/- 85 volt @ 10 amps requires over 2kW input power and you should consider a full bridge.
chas1
luka said:
I really appreciate your response....
I am going to go for a 250 to 350 per channel power amp, something like a Leach or similar. I have built a 700 watt but that is another story. I just want to get my feet wet, but not drown now that I have the time in my semi-retirement.
I have started a spreadsheet for the SMPS portion of this project. It is for everyone to see and share if so desired.
I will leave it open for now, but if it get trashed for any reason I will restrict access.
take a look at: http://spreadsheets.google.com/ccc?key=pUZgdFvKxvFGnJ-VNhx9eKQ&hl=en
Enjoy thanks for sharing your time and talent. I will do the same with what little I have...
Re: spec's for supply
Thanks Chas
Would you point me to the schematic that shows the full and the half bridge, I am totally lost on this part.
I have built some small SMPS in my day, but nothing with the power of this design...
Thanks for your help....
chas1 said:
Thanks Chas
Would you point me to the schematic that shows the full and the half bridge, I am totally lost on this part.
I have built some small SMPS in my day, but nothing with the power of this design...
Thanks for your help....
full bridge & halfbridge schematic
If you go to the URL below and click on Power Supply Schematic you will find a FB design, the complete construction details,parts lists and PCB.
This supply was designed to power the Audio Amp K6 and is an excellent design and will work out of the box as for HB in this thread you will find a schematic of my design which is good up to a kW and should power the Leach amp or Leach supperamp which if I remember require about +/- 40 volts @5 amp
chas1
http://www.a-and-t-labs.com/K6_Sw_Amp/index.htm
If you go to the URL below and click on Power Supply Schematic you will find a FB design, the complete construction details,parts lists and PCB.
This supply was designed to power the Audio Amp K6 and is an excellent design and will work out of the box as for HB in this thread you will find a schematic of my design which is good up to a kW and should power the Leach amp or Leach supperamp which if I remember require about +/- 40 volts @5 amp
chas1
http://www.a-and-t-labs.com/K6_Sw_Amp/index.htm
Re: full bridge & halfbridge schematic
Why didn't just say so in the first place.....
I am so impressed with your hard and very good work. Now if I can just get the boss to approve the funds for the fun to be had to bring it to life. She will I think.
But the K6 will keep me busy for a year or two.
Thanks for the information.
chas1 said:
Why didn't just say so in the first place.....
I am so impressed with your hard and very good work. Now if I can just get the boss to approve the funds for the fun to be had to bring it to life. She will I think.
But the K6 will keep me busy for a year or two.
Thanks for the information.
Amplifiers
I don't want to mislead anyone, the K6 amp along with the smps was designed by Reinhard Metz and Myzil Boyce, I have constructed the power supply and it functions well. I did not build the K6 as I use my own amp design and have since designed and constructed a halfbridge power supply that powers it. In doing so I have studied many designs,appnotes and purchased some excellent books on the subject and I also purchased a book by Christophe Basso titled Switchmode Power Supply Spice Cookbook which enabled me to simulate using spice various parts of the smps and the complete supply itself along with a quick way to design the feedback and close the loop. A good read, should be on your reading list.
chas1
I don't want to mislead anyone, the K6 amp along with the smps was designed by Reinhard Metz and Myzil Boyce, I have constructed the power supply and it functions well. I did not build the K6 as I use my own amp design and have since designed and constructed a halfbridge power supply that powers it. In doing so I have studied many designs,appnotes and purchased some excellent books on the subject and I also purchased a book by Christophe Basso titled Switchmode Power Supply Spice Cookbook which enabled me to simulate using spice various parts of the smps and the complete supply itself along with a quick way to design the feedback and close the loop. A good read, should be on your reading list.
chas1
chas1,
howdy, i was looking for your half bridge circuit, is it posted on here somewhere?
how did you decide what decoupling capacitor to use? sizing for current, that is.
thanks
howdy, i was looking for your half bridge circuit, is it posted on here somewhere?
how did you decide what decoupling capacitor to use? sizing for current, that is.
thanks
Re: Re: full bridge & halfbridge schematic
http://www.a-and-t-labs.com/K6_Sw_Amp/art_schematic/k6pwr.pdf
This is a voltage mode full-bridge correct? How do you keep the transformer from walking up bh curve? I do not see a series primary cap.
http://www.a-and-t-labs.com/K6_Sw_Amp/art_schematic/k6pwr.pdf
This is a voltage mode full-bridge correct? How do you keep the transformer from walking up bh curve? I do not see a series primary cap.
series cap for xfmr
jamesrnz
If you have this book "High frequency Switching Power Supplies"
go to page 31 . The full explanation is there, if you don't here it is
Thanks to George Chryssis:
The coupling cap along with the output filter inductor form a resonant circuit whose frequency is:
fr = 1 /6.28 *sqrt(LR*C)
where fr = resonant frequency in kHz
C= coupling cap in uF
LR = reflected filter inductance
reflected inductance is LR = (Np/Ns)^2 * L
where Np/Ns is turns ratio and L is output inductance(uH)
Then C = 1/(4*3.14^2*Fr^2*(Np/Ns)^2*L)
This is how its calculated in this book. As for my self I don't use it and I don't have any problem because the two resistors across the input caps balance the center if you use two 2.5u to 10u caps in parallel depending on load current. this point stays around 160 volts in my halfbridge. Refer to my schematic. You might have to adjust the value for input ripple at low line for if it is to large it will interfere with the regulation. A good value is .1u to 2uf, you can get these caps from an old PC power supply and parallel them if more capacitance is needed.
chas1
jamesrnz
If you have this book "High frequency Switching Power Supplies"
go to page 31 . The full explanation is there, if you don't here it is
Thanks to George Chryssis:
The coupling cap along with the output filter inductor form a resonant circuit whose frequency is:
fr = 1 /6.28 *sqrt(LR*C)
where fr = resonant frequency in kHz
C= coupling cap in uF
LR = reflected filter inductance
reflected inductance is LR = (Np/Ns)^2 * L
where Np/Ns is turns ratio and L is output inductance(uH)
Then C = 1/(4*3.14^2*Fr^2*(Np/Ns)^2*L)
This is how its calculated in this book. As for my self I don't use it and I don't have any problem because the two resistors across the input caps balance the center if you use two 2.5u to 10u caps in parallel depending on load current. this point stays around 160 volts in my halfbridge. Refer to my schematic. You might have to adjust the value for input ripple at low line for if it is to large it will interfere with the regulation. A good value is .1u to 2uf, you can get these caps from an old PC power supply and parallel them if more capacitance is needed.
chas1
series cap
switchmodepower
This is not my design and even though text books mention that it might be needed in halfbridge they also say that it might be excluded in fullbridge designs. I have three different supplies that I have constructed after spice simulation and one before and I don't use this cap. I have had it in the circuit and removed it for testing and find no difference even when I operate the supply in an oven and an icewater bath. I am currently designing a halfbridge current mode and a two switch forward converter so I am switching from voltage to current mode for all those reasons. I will say if you operate the supply in the DCM and you don't close the feedback loop properly you will see some nasty center point current wave forms because of the frequency shift of the poles and zeros along with the output Zo. I might mention I don't intend to sale any of my work commercially, its is for my use and education.
chas1
switchmodepower
This is not my design and even though text books mention that it might be needed in halfbridge they also say that it might be excluded in fullbridge designs. I have three different supplies that I have constructed after spice simulation and one before and I don't use this cap. I have had it in the circuit and removed it for testing and find no difference even when I operate the supply in an oven and an icewater bath. I am currently designing a halfbridge current mode and a two switch forward converter so I am switching from voltage to current mode for all those reasons. I will say if you operate the supply in the DCM and you don't close the feedback loop properly you will see some nasty center point current wave forms because of the frequency shift of the poles and zeros along with the output Zo. I might mention I don't intend to sale any of my work commercially, its is for my use and education.
chas1
Re: series cap
That's surprising because what ensures proper symmetry? Maybe if you have the xfmr gapped and you have matched FETs it will always work but I bet if you get mismatched FETs you will have problems.
chas1 said:
That's surprising because what ensures proper symmetry? Maybe if you have the xfmr gapped and you have matched FETs it will always work but I bet if you get mismatched FETs you will have problems.
reply
If you looking for someone to discuss this with try Col. Wm. T. Mclyman he has a couple of designs in his book and neither use this cap and you can refer to Jim Buckwalter design of a 500 watt HB for class E amplifiers and other's but in the end you should design your supplies the way you like I am not going to debate the issue with you and a by the way I used old mosfets to prove my work and changed them at will with no problem , works for me. I am not trying to be the guru just supplying the best info I have and this forum advocates that all do their own research.
chas1
If you looking for someone to discuss this with try Col. Wm. T. Mclyman he has a couple of designs in his book and neither use this cap and you can refer to Jim Buckwalter design of a 500 watt HB for class E amplifiers and other's but in the end you should design your supplies the way you like I am not going to debate the issue with you and a by the way I used old mosfets to prove my work and changed them at will with no problem , works for me. I am not trying to be the guru just supplying the best info I have and this forum advocates that all do their own research.
chas1
chas1,
ok just got his book, i like it it is small but has good information and i like the examples.
is your HB schem posted on here somewhere?
ok just got his book, i like it it is small but has good information and i like the examples.
is your HB schem posted on here somewhere?
schematic
Yes it should be, I posted it a couple of times. If you use the example to calculate your supply it will work the first time, I used IGBTS and a small transformer that I wound on a PC core about the same as EC19 and used a buffer circuit to drive it to lighten the load on control IC outputs (SG3525 ). All the info you need is in the book. I attended one of his seminars in the 1980's where I recieved the book and it is my go to reference.
chas1
Yes it should be, I posted it a couple of times. If you use the example to calculate your supply it will work the first time, I used IGBTS and a small transformer that I wound on a PC core about the same as EC19 and used a buffer circuit to drive it to lighten the load on control IC outputs (SG3525 ). All the info you need is in the book. I attended one of his seminars in the 1980's where I recieved the book and it is my go to reference.
chas1
Valenca said:Hi Luka, how i connect the Half bridge SMPS in 110VAC.
Help - me please !
Thanks.
Sorry I didn't reply, didn't see it...How can you?, on my board you can't. but what you would need to do is
Can you see where 110 is writen, near bridge rectifier? I don't have that connection, because it is for 230V, if you would make it, you would run it from 110v. But like I said, my wouldn't work, not with elements that I used(trafo).