Thanks for your response, savu.
By the way byv27 is 25ns trr.
And something regardign the choke.
Can i use ferroxcube 23/14/7 4c65 ferrite core (seems to be available).
Ok no problem at all. mur 120 is also available!!!!!!!! BYV27 has larger forward drop (1V)🙂
But mur 120 is rated at 1A.
Dont you feel the BYV is better for charging (b'strap cap) / discharging heavy input capacitances (1750pF) ?
I think i would use 5615s.
By the way byv27 is 25ns trr.
And something regardign the choke.
Can i use ferroxcube 23/14/7 4c65 ferrite core (seems to be available).
Ok no problem at all. mur 120 is also available!!!!!!!! BYV27 has larger forward drop (1V)🙂
But mur 120 is rated at 1A.
Dont you feel the BYV is better for charging (b'strap cap) / discharging heavy input capacitances (1750pF) ?
I think i would use 5615s.
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hello newvirus2008,
try to use micrometals core nr 2 for example T106-2
mur120 is ok .. you won't need more than 1 amp.
regards,
later edit:
you can use TN23/14/7 4c65. just checked.
try to use micrometals core nr 2 for example T106-2
mur120 is ok .. you won't need more than 1 amp.
regards,
later edit:
you can use TN23/14/7 4c65. just checked.
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I have no snubber at present. Do i need to add one?
And is there any special capacitor that i should use for the output filter?
And is there any special capacitor that i should use for the output filter?
you may use snubbers if you have ringing at the output.
as cap for the output try to use a good non polarised one like wima for example.
regards,
savu
as cap for the output try to use a good non polarised one like wima for example.
regards,
savu
No. I have to order the parts. decided on mosfets, choke only today.
I m trying to save some shipping by ordering as many parts as poss.
Also, i may have had to change footprint had i opted any bigger choke!
Anyway i am adding provision for snubber at output may or maynot use it.
I m trying to save some shipping by ordering as many parts as poss.
Also, i may have had to change footprint had i opted any bigger choke!
Anyway i am adding provision for snubber at output may or maynot use it.
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so ...
-you have to make a very tight pcb layout.
-i suggest smd parts for best results.
-place the power fets as close to the drive ic as possible.
-place the filter caps of the rails as close to the power fets as possible.
-use 100nf caps in paralel with the filter caps.
-use only low ers caps on the amp boards for the electrolitic tipe ones.
-make sure that gate traces are as short as possible.
-avoid using 90 dergree angles in the pcb traces.
-place a 1uf/ 250v minimum from high side power fet draine to low side power fet source (use wima or othe high quality non polarised cap).
-better use ir2010 instead of ir2110 (it's a bit faster).
-put a 10pf cap in paralel with the resistor going to the level shift transistor (from comp out to emmiter).
-use a faster comparator, preferably to be in 8 pin capsule since you don't need to waste space.
-the power fets IRFB5615 can withstand 70V rails (you should use this because you will have lower current drawn from the psu and fets).
-place the output inductor vertical if you intend to use toroid.
regards,
savu
-you have to make a very tight pcb layout.
-i suggest smd parts for best results.
-place the power fets as close to the drive ic as possible.
-place the filter caps of the rails as close to the power fets as possible.
-use 100nf caps in paralel with the filter caps.
-use only low ers caps on the amp boards for the electrolitic tipe ones.
-make sure that gate traces are as short as possible.
-avoid using 90 dergree angles in the pcb traces.
-place a 1uf/ 250v minimum from high side power fet draine to low side power fet source (use wima or othe high quality non polarised cap).
-better use ir2010 instead of ir2110 (it's a bit faster).
-put a 10pf cap in paralel with the resistor going to the level shift transistor (from comp out to emmiter).
-use a faster comparator, preferably to be in 8 pin capsule since you don't need to waste space.
-the power fets IRFB5615 can withstand 70V rails (you should use this because you will have lower current drawn from the psu and fets).
-place the output inductor vertical if you intend to use toroid.
regards,
savu
hi savu,
- My PCB as tight as possible, i hate soldering smds, maybe will try full smd afterwards.
- Mosfets closest , if closer then footprints overlap.
- Caps (220uF/200V) will be close with 100nf parallel. Sure! 10000uF outside board.
- Power & high frequency traces shortest possible with t'hole components.
- No 90 degrees already! Two obtuse angles make the 90 deg turn.
- Drain HI to source LO 1uF NP sure.
- I have bought 2110 already! will try other like 2010 and LM51xx (100V only) next time.
- 10pF footprint already in PCB (pls see layout) forgot to mention in circuit.
- Will try LM360 (SMD)next time.
- Will try to use DirectFets (with little or no h'sink) next time with full smd!
- My inductor already vertical.
- My PCB as tight as possible, i hate soldering smds, maybe will try full smd afterwards.
- Mosfets closest , if closer then footprints overlap.
- Caps (220uF/200V) will be close with 100nf parallel. Sure! 10000uF outside board.
- Power & high frequency traces shortest possible with t'hole components.
- No 90 degrees already! Two obtuse angles make the 90 deg turn.
- Drain HI to source LO 1uF NP sure.
- I have bought 2110 already! will try other like 2010 and LM51xx (100V only) next time.
- 10pF footprint already in PCB (pls see layout) forgot to mention in circuit.
- Will try LM360 (SMD)next time.
- Will try to use DirectFets (with little or no h'sink) next time with full smd!
- My inductor already vertical.
Errr...........It must be horizontal with respect to pcb and must have a ground plane underneath it.
Hello Konwar,
you are right, but this is a 200W amp. i don't think that will have an effect.
regards,
savu
you are right, but this is a 200W amp. i don't think that will have an effect.
regards,
savu
Not True, Even if the amp is 10W, EMI and stray magnetic field will do its job well enough to corrupt the modulator with noise injection if toroid is mounted vertically.
Kanwar
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I dont think i have enough board space for a horizontal toroid.
1 inch min dia! Is there any way i can get away by shielding the choke? Or what if I shield the modulator like the RF front-end box inside a TV?
I have an ATX PSU box lying around which will be the case. It should be very close to the board (when screwed) and act as a ground plane..
1 inch min dia! Is there any way i can get away by shielding the choke? Or what if I shield the modulator like the RF front-end box inside a TV?
I have an ATX PSU box lying around which will be the case. It should be very close to the board (when screwed) and act as a ground plane..
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Try the horizontal mount next time you make another pcb, abhi jugaad ko chaalu to kar.
Ok my new updated layout with RC snubber, 100n parallel with bus caps, bus caps closer to MOSFETS.
No place for cap from HI drain to LO source.....
No place for cap from HI drain to LO source.....
What about the resistor wattages? What about the snubber? Do any of the resistors require > 0.25W?
My schematic already posted. I also want to add overcurrent protection. What current sense should I use?
My schematic already posted. I also want to add overcurrent protection. What current sense should I use?
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You haven't done your home work yet which includes searching the threads under class-D section for your queries. There is plenty of information regarding your questions. 😉
Hi workhorse,
Sorry, I agree that I havent done much of it but i am doing it.....
And abt the layout , i think i can have a horizontal toroid!!!!! 🙂
Sorry, I agree that I havent done much of it but i am doing it.....
And abt the layout , i think i can have a horizontal toroid!!!!! 🙂
You just changed the direction of your toroid....to.....90 degrees and its still perpendicular to the pcb.......so its not horizontal anywhere.😀
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