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MHz class d amp

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F

facade

Member
Joined 2006
fumac said:
rogs I would have written it as 'Big Brother is Watching You!!'

:):)
i'm the Big Brother at my home:clown: :clown:
Click to expand...


please refer to George Owell's 1984 for 'big brother'
:cool:
PHILIPS patent covers:
1.a single voltage feedback from power output
2. the feedback consist of two element, one(resistor) for gain, one(r+c) for switching
3. the structure of comparator, the current mirror...
4.the active-pull driver for mosfet
and some other things
I think it's not easy to avoid all these claims

Apparently you guy want to make money on it, so we should not expect to see your design details. Anyway, it's pretty good. I'm looking forward to get kit from your online store for it
:cool:
hurry up! I'd like to see more test result of your baby
 
F

fumac

Member
Joined 2006
class-d.net
facade said:



please refer to George Owell's 1984 for 'big brother'
:cool:
PHILIPS patent covers:
1.a single voltage feedback from power output
2. the feedback consist of two element, one(resistor) for gain, one(r+c) for switching
3. the structure of comparator, the current mirror...
4.the active-pull driver for mosfet
and some other things
I think it's not easy to avoid all these claims

Apparently you guy want to make money on it, so we should not expect to see your design details. Anyway, it's pretty good. I'm looking forward to get kit from your online store for it
:cool:
hurry up! I'd like to see more test result of your baby
Click to expand...

i just show picture that when the kit runing on 1MHZ ,
i have not sell anything here:)
if u dont like my test,i'll not post any new PIC here,
and pls close this topic.
if somebody like pls goto http://class-d.net
and i will post on my web (will have an english ver)
(my test is true,if u have a chance to china,wellcome to my lab),

my sch is base on it, but not the same, including 1,2,3 ,4 that u say:) another, i'm going to fine a new way.

tks for ur advise.

btw,i'm Disappointed that nobody had say anything about the test
:(
amp not just by ear
 
F

fumac

Member
Joined 2006
class-d.net
Netlist said:


How can you expect serious discussion without even a basic schematic. A scope picture can be nice or not and yours appear to be ok but that's about all that can be said for now.

/Hugo
Click to expand...


do u test ur ucd or another AMP?
if do, i like to see:)

i had tested TDA8920 ,CLASS-T TA2222, UCD, THEY LOOK diffrent on the SCOPE, i need't to look inside the chip:)

MY FIRST AMP PROJECT IS CLASS-T , SOME people say it sound great, i found the bass of it is not good(just i think)

2nd project isTDA8920, bass is ok,but Treble is not sweet,and the power is not Enough £¬SO i Give up£¬I even have 20 chips, they just lay down on the box
this is the pcb of it
http://www.class-d.net/UploadFiles/200719205623223.jpg

3,I MAKE THE UCD for 3 times, when i get the sch ,i think ,it's a great design.!
but 400k~600k IS NOT the best chioce in audio amp.
so i chage something,and driver it up to 1.mhz(next will be 1.5~2mhz),

if u can test ur ucd, we can see sth

nice to meet u
 
R

rogs

Member
Joined 2006
theAnonymous1 said:
I think it translates more like "The enemy is listening".
Click to expand...

You're right of course - from the WW2 Nazi slogan -- in the UK our equivalent phrase was 'Careless Talk Costs Lives', and the USA had 'Loose Lips Sinks Ships'.

I was thinking more along the lines of the 'Big Brother' concept being more up to date.

Although it's Bruno's name on the patent, it's owned by Philips, and they are the 'Big Brother' that would have to defend any infringements. :)

I keep forgetting that, for many members on this forum, English is not their first language - and many of them write better English than those of us whose first language is English!! -- very humbling!

So Bruno is Belgian, works in Holland, and writes in English like a native English speaker.

And then posts an enigmatic quote - in German :)

Is there no end to this man's talent!! :D
 
E

eleson

Member
Joined 2006
Is it possible to bring this one back on topic?

Why 1.2 Mhz?

What's the values of output cap. and coil?

Is there a risk that this is a design that every neighbour can here on the radio?

How do we get more understanding of how it sounds?

And maybe to the moderators, why did this one end(?) up
in vendor's bazaar when so many other companies post
on Class-D?

To me it is much more natural to move, for instance, the SMPS discussions to a proper place.

BR
Erland
 
S

Spasticteapot

Member
Joined 2006
eleson said:
Is it possible to bring this one back on topic?

Why 1.2 Mhz?

What's the values of output cap. and coil?

Is there a risk that this is a design that every neighbour can here on the radio?

How do we get more understanding of how it sounds?

And maybe to the moderators, why did this one end(?) up
in vendor's bazaar when so many other companies post
on Class-D?

To me it is much more natural to move, for instance, the SMPS discussions to a proper place.

BR
Erland
Click to expand...

1.2mhz is right in te middle of the FM band. Put it in a metal box.

I'm personally in favor of using a filter/surge protector on anything class-D: I can get them used for $6, and what harm can I do?
 
Netlist

Netlist

Moderator
Joined 2003
Paid Member
eleson said:

And maybe to the moderators, why did this one end(?) up
in vendor's bazaar when so many other companies post
on Class-D?
Click to expand...

Since the thread starter apparently doesn’t disclose a schematic, links to a commercial site, doesn’t answer (or very vaguely) any technical question that might lead to a fruitful discussion, we decided that this is a pure commercial venture. We are willing to accept the language barrier.
If you find other similar examples that need moved out of class D, just let us know.

/Hugo
 
E

eleson

Member
Joined 2006
Netlist said:

Since the thread starter apparently doesn’t disclose a schematic, links to a commercial site, doesn’t answer (or very vaguely) any technical question that might lead to a fruitful discussion, we decided that this is a pure commercial venture. We are willing to accept the language barrier.
If you find other similar examples that need moved out of class D, just let us know.
/Hugo
Click to expand...

Thanks.
/Erland
 
F

fumac

Member
Joined 2006
class-d.net
Spasticteapot said:


1.2mhz is right in te middle of the FM band. Put it in a metal box.

I'm personally in favor of using a filter/surge protector on anything class-D: I can get them used for $6, and what harm can I do?
Click to expand...

1.2mhz it the sw band not in fm band
the EMI is well
it just output 0.175V@1MHz ON the output cable.
on the new mcd2 we used 4 orders filter, (mcd-1 is 2 orders)
i'll be more low compact with radios.
 
F

fumac

Member
Joined 2006
class-d.net
eleson said:
Is it possible to bring this one back on topic?

Why 1.2 Mhz?

BR
Erland
Click to expand...

i post a table here,

audio freq: 20 250 500 1K 2K 5K 10K 15K 20K
PWM freq
100K 5000 400 200 100 50 20 10 7 5
300K 15000 1200 600 300 150 60 30 20 15
500K 25000 2000 1000 500 250 100 50 33 25
600K 30000 2400 1200 600 300 120 60 40 30
1000K 50000 4000 2000 1000 500 200 100 67 50
2000K 100000 8000 4000 2000 1000 400 200 133 100

it shows how many point(of the audio freq) that the PWM can Capture
more points that u catch, the output and intput will be more like
u can find that if u want more points, u have to driveup the FREQ of pwm
for 500K pwm freq,it just catch 20 points of 20K audio
i think it's not Enough for high proformence.
my english is pull and i cant use it to write my mine.
this is the chinese ver that wrote by me
http://bbs.21ic.com/club/bbs/list.a...7F3%u8D28%u548C%u57FA%u9891%u7684%u5173%u7CFB
 
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