pls post the schematic you used.
did you use irfp240 @ +/-80v dc? how is the sound and the heat ?
did you use irfp240 @ +/-80v dc? how is the sound and the heat ?
schematic
This is my schematic with overload protection. Sound on stabilized power supply +-30V is very clear without any parasite sounds. And when amp is on smps +/-80V sound is OK with little bit regulation frequency sound from SMPS and temp is also OK. Measured RMS power is 650W with 4 Ohm load. 😀 Mosfets are IRFP 250.
This is my schematic with overload protection. Sound on stabilized power supply +-30V is very clear without any parasite sounds. And when amp is on smps +/-80V sound is OK with little bit regulation frequency sound from SMPS and temp is also OK. Measured RMS power is 650W with 4 Ohm load. 😀 Mosfets are IRFP 250.
Attachments
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Thanks for sharing.🙂
I do not know if i will be able to make dual side pcb with traces other than ground plane on top.🙁
Anyway you pcb has also long traces..feeback is very long and near output inductor and switching bus 😱 ... but you have alot of ground
..it looks alot like my test board layout.If it sounds good ... have you made any distorsion analysis?😕
Please someone make the following ear distosion test .
Use 1kz sine wave.Se volume for 10-15 volt rms output. Put a 470 ohm resistor between speaker and output.Connect and disconnect 2 ohm load and listem for any changes in sound.Also watch output signal form on scope.
Thanks again.
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thanks fibko for your design GOD bless you big .
you have not used lori laci design approach in the lm311 . are you sure your amp is silent especially now that it is stereo
and is your over current working well ? have you tested it with the +/- 80v dc with a 1ohm load as speaker?
you have not used lori laci design approach in the lm311 . are you sure your amp is silent especially now that it is stereo
and is your over current working well ? have you tested it with the +/- 80v dc with a 1ohm load as speaker?
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Over current protection is from philips UCD amp http://www.nxp.com/documents/user_manual/UM10155.pdf and when the protection was very sensitive i got from amp approximately 300 W RMS. My test was only with 4 Ohm load. My measurement results are here http://www.diyaudio.com/forums/class-d/166214-ucd-25-watts-1200-watts-using-2-mosfets-119.html
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I can see in your schematic Signal Input is PIN 3 - @ LM311
other schematic from Dzony_988 has Signal Input PIN 2 + @ LM311
is this correct in your schematic ?
Do you use your amp for Fullrange ?
how about noise ?
silent, without noise and hum, in mid and highs ,... i cant believe ?
I thing that is cool, but not ideal. On my stabilized power supply amp run without any noise, but on SMPS amp produces weak noise. I thing it is from power supply because I don´t have ideal filtering. And when amp run in stereo from one power supply, generate whistle. Therefore, one side run @ 200kHz and other side run @ 250kHz.
hi fibko, even i made the amp with the original schem and it produced noise which i was unable to eliminate. I used to use it as a sub amp because the noise in the mid was kind of boring, not much but boring. And with an SMPS as power supply it almost doubled(the noise) but since you say its clear, and no noise, you must be lucky. The class D i made and had no noise was by class D from RU http://www.diyaudio.com/forums/class-d/91773-pictures-circuits-my-diy-class-d-other-projects.html
By the way, how can you increase or decrease the sensitivity of your protection circuit?
By the way, how can you increase or decrease the sensitivity of your protection circuit?
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@stewin
Calculate curent on output on +-80V on 4 ohm load. Calculate amp curent on +-80V on 4 ohm load. Then calculate volatge drop on shunt resistor, and when you got on example 1V drop, then you can change value of shunt resistor for diferente power supplays and imedance (you must always have 1V drop on shunt resistor, that is reason you change value of shunt resistor)
Calculate curent on output on +-80V on 4 ohm load. Calculate amp curent on +-80V on 4 ohm load. Then calculate volatge drop on shunt resistor, and when you got on example 1V drop, then you can change value of shunt resistor for diferente power supplays and imedance (you must always have 1V drop on shunt resistor, that is reason you change value of shunt resistor)
I do not use shunt resistor..but shunt wire(or inductor but is optional) in output path..power loss is much smaller...50-150 mV drop ..
It is simply a wound wire with or without ferrite core(with core if you want to filter output noise better).Voltage drop across it goes to a differentiator and a comparator.On stereo amplifiers(not bridge-able) differentiator op amp is not needed, also shunt voltage can be as low as 10 mV.
Shunt rezistor is good for power supply noise filtering and peak amperage smoothing but must be placed between high value capacitors,in this configuration it can not be used for short/over power protection.
Shunt rezistor is good for power supply noise filtering and peak amperage smoothing but must be placed between high value capacitors,in this configuration it can not be used for short/over power protection.
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do you have schematic, without schematic i only can imagine something in my head!? do you try that and can i adjust sens on other levels...
What is tiknes of wire because voltage drop rise with current on constant R of wire..
can i use on example 0.01ohm resitor
What is tiknes of wire because voltage drop rise with current on constant R of wire..
can i use on example 0.01ohm resitor
I think we can forget this class D amp design for fullrange, its waste our time
a lot of new postimgs from diy members but since today there is no solution to remove noise for fullrange.
I will not leave my reliable working QUASI NMOS amp from "power amp under development" UCD Class D no way
@NMOS
I dont know how many time I have to tell you that problem is with you. I dont have a noise (even with 1nF) and mine is full range. You have to use better components, better PCB layout and better filtering/grounding. Most of us is corectly resloved problem, I really dont know what is yours but you have to share with us your pcb, schematic, and finaly finished look how can we help you.
You cant only sit, pray that one day amp will work good. You have to try something new, share your documents and alone reslove problem..
I dont know how many time I have to tell you that problem is with you. I dont have a noise (even with 1nF) and mine is full range. You have to use better components, better PCB layout and better filtering/grounding. Most of us is corectly resloved problem, I really dont know what is yours but you have to share with us your pcb, schematic, and finaly finished look how can we help you.
You cant only sit, pray that one day amp will work good. You have to try something new, share your documents and alone reslove problem..
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