Have you checked the schemo ?
Also who said im going to power up B+ before the 12v ?
I removed the lytis and replaced them with some small caps.
An externally hosted image should be here but it was not working when we last tested it.
Also who said im going to power up B+ before the 12v ?
I removed the lytis and replaced them with some small caps.
An externally hosted image should be here but it was not working when we last tested it.
Look nice except the 7805, maybe to slow to fully turn on...Try it, if you blow your mosfet at turn on, change this for 5.1V zener with 330 ohms resistor. That the way I use it!
Fredos
Fredos
I aint got any 5v zeners @ home 🙁 I have to source some down, or maybe u know some junk i could steal a few from.
And if i have to use zeners due to too slow Vreg´s, i wouldent need to chage any on the board eh, just stick them into existing holes for the Vreg.
Btw which 7805 are you talking about ? There are three of them on the board. 😕
Tho i dont think shoot through should be a problem, remember that one gate driver is inverting and the other is not, and both either see 5v in or 0v in during startup and thus only one fet will be turned on, unless you see something that i don´t.
And if i have to use zeners due to too slow Vreg´s, i wouldent need to chage any on the board eh, just stick them into existing holes for the Vreg.
Btw which 7805 are you talking about ? There are three of them on the board. 😕
Tho i dont think shoot through should be a problem, remember that one gate driver is inverting and the other is not, and both either see 5v in or 0v in during startup and thus only one fet will be turned on, unless you see something that i don´t.
hello all,
can anyone post link/file of IRF520/motorola ??
I have them mosfets BUT I cant seem to find datasheet(on the net)....
can anyone post link/file of IRF520/motorola ??
I have them mosfets BUT I cant seem to find datasheet(on the net)....
tekko,
FYI, its NOT 🙄
DL a component datasheet with different makes... compare... and SEE what I mean...
FYI, its NOT 🙄
DL a component datasheet with different makes... compare... and SEE what I mean...
Bastards!!
7805 on the mosfet drivers...Maybe OK with your inverting and non-inverting configuration...Why did you that after the optocoupler? Better before to have identical switching...
Fredos
Fredos
Only time will tell, if it *POOF* or works.
Only 1.5-2 weeks left before i can make a first test.
Only 1.5-2 weeks left before i can make a first test.
The boards for this thing is now ordered, they´ll arrive somewhere in next week.
Cost, alittle over $40 for two dual layer boards with though plated holes.
Cost, alittle over $40 for two dual layer boards with though plated holes.
Hello,
I try to understand how works class D amp,
I've learn about pwm modulation and how it's work for a class D amp. I understood that pwm modulation can be done with a comparator. Entries of this comparator are trig form signal and low level audio signal.
With this informations I could understand how works first shematic from Nitrate, indeed there are trig generator (with LM358N) and a comparator (LM393N). Fine I understood althoug I still don't understand why there are so many 74HC14...
In the last shematics from Nitrate and Tekko LM393 and LM358 are removed. Maybe because it is possible to have a trig generator using a 74HC14 chip replacing the LM358N, but I don't understand why there is no comparator anymore...
So could you explain why there is no LM393? A new design to have pwm modulation without comparator? A piece of new shema which replace LM393?
Thank for you help, now I will return study hom to get a sinus wave form with a pwm form and a L-C filter 🙂
I try to understand how works class D amp,
I've learn about pwm modulation and how it's work for a class D amp. I understood that pwm modulation can be done with a comparator. Entries of this comparator are trig form signal and low level audio signal.
With this informations I could understand how works first shematic from Nitrate, indeed there are trig generator (with LM358N) and a comparator (LM393N). Fine I understood althoug I still don't understand why there are so many 74HC14...
In the last shematics from Nitrate and Tekko LM393 and LM358 are removed. Maybe because it is possible to have a trig generator using a 74HC14 chip replacing the LM358N, but I don't understand why there is no comparator anymore...
So could you explain why there is no LM393? A new design to have pwm modulation without comparator? A piece of new shema which replace LM393?
Thank for you help, now I will return study hom to get a sinus wave form with a pwm form and a L-C filter 🙂
IRF520 is from International Rectifier
Try this link
https://ec.irf.com/v6/en/US/adirect/ir?cmd=catProductDetailFrame&productID=IRF520
peace
Try this link
https://ec.irf.com/v6/en/US/adirect/ir?cmd=catProductDetailFrame&productID=IRF520
peace
Are you asking if the IRF520 is from Motorola or are you stating that it is from Moto
First of all Motorola does not exits anymore, it turn into OnSemi and another branck into Freescale, second had you tried to follow the link ...it points to International Rectifier the original manufacturer of the IRF520. Third if you have some parts labeled IRF520 fom Motorola then they maybe were 2nd sourced.
Man why I bother....
First of all Motorola does not exits anymore, it turn into OnSemi and another branck into Freescale, second had you tried to follow the link ...it points to International Rectifier the original manufacturer of the IRF520. Third if you have some parts labeled IRF520 fom Motorola then they maybe were 2nd sourced.
Man why I bother....
Re: Are you asking if the IRF520 is from Motorola or are you stating that it is from
1st of all, I HAVE IN HAND, an IRF520 -MADE- by motorola....
2nd , WOULD I BOTHER seeking help HERE if I already found a datasheet of it???
common sense dude!! im NOT that stupid you know....
peace
groov said:
1st of all, I HAVE IN HAND, an IRF520 -MADE- by motorola....
2nd , WOULD I BOTHER seeking help HERE if I already found a datasheet of it???
common sense dude!! im NOT that stupid you know....
peace
groov, Motorola still exists, but they only make cellphones and stuff now. It was motorola semi that turned into onsemi.
RX5, i dunno how old the fet you have is, but onsemi´s datasheet is prolly the closest u´ll come, as they are former motorola semi.
RX5, i dunno how old the fet you have is, but onsemi´s datasheet is prolly the closest u´ll come, as they are former motorola semi.
Hi guys,
I'm very interested in class D audio amp, so after reading of this topic I decided to try myself.
I didn't completely understand shema from tekko and nitrate especially for the preamp parts. So I made a logic stage from myself, using as preamp a simple AO (follower and level shifting stage) a trig generator with 74hc14 gate like nitrate and a comparator (hysteresis working with 0-5V).
I got a pwm signal which seems to be good (I haven't a enough fast scope to check it properly)
For testing I put a LC filter at the output of logic stage (L=scrap from atx psu, thanks for the idea nitrate 😉 and a mkp 0.47µF)
And with a walkman type speaker I heard music!
So I validate my logic stage and now I will work on power stage. For power stage I will use shematic from tekko with UCC3722/21 mos driver (I think I well understand this stage with bootstrap voltage to enhance mos driver performance)
Many thanks to nitrate and tekko indeed I use parts of your shematic and without reading post from you I will probably never try the breadboard class D amp experience!
I will post some pics and shema as soon as my amp becomes interesting.
Flo, a beginner electronic engineer (with poor english...sorry)
I'm very interested in class D audio amp, so after reading of this topic I decided to try myself.
I didn't completely understand shema from tekko and nitrate especially for the preamp parts. So I made a logic stage from myself, using as preamp a simple AO (follower and level shifting stage) a trig generator with 74hc14 gate like nitrate and a comparator (hysteresis working with 0-5V).
I got a pwm signal which seems to be good (I haven't a enough fast scope to check it properly)
For testing I put a LC filter at the output of logic stage (L=scrap from atx psu, thanks for the idea nitrate 😉 and a mkp 0.47µF)
And with a walkman type speaker I heard music!
So I validate my logic stage and now I will work on power stage. For power stage I will use shematic from tekko with UCC3722/21 mos driver (I think I well understand this stage with bootstrap voltage to enhance mos driver performance)
Many thanks to nitrate and tekko indeed I use parts of your shematic and without reading post from you I will probably never try the breadboard class D amp experience!
I will post some pics and shema as soon as my amp becomes interesting.
Flo, a beginner electronic engineer (with poor english...sorry)
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