600W Class D amp

[badboy6120]

by removing 1nf cap from pin 2 of TL071 there would be around rail voltage at output
also disconnecting pin 2 of TL071 from feedback will cause no signl in output

 

[manojtm]

Hi,

I don't know why but I get about 185KH frequency with 1K resistor and 135KH with 560 ohms resistor
with 1k resistor:

with good coil your freq. will go high up to 435KHz (same MOSFET)

Regards
MANOJ

 

[manojtm]

Hi,

by removing 1nf cap from pin 2 of TL071 there would be around rail voltage at output
also disconnecting pin 2 of TL071 from feedback will cause no signl in output

Sorry the FB link erased. its my mistake connect FB and remove 1nF cap

without 1nF cap, with your coil you get approx. 235KHz

Regards
MANOJ

 

[badboy6120]

Hi,

with good coil your freq. will go high up to 435KHz (same MOSFET)

Regards
MANOJ

I have T106-2 core
how much turn on it to test the frequency problem?

 

[badboy6120]

Reduced the ETD39 turns to 20 and now I get about 250KHZ with 1kohm resistor(lower value will decrease frequency)

 

[badboy6120]

I think that 14 Volts drops in output voltage is dissapated in output core winding because it gets really hot in a few second
can I use multiple threaded wire gauge like 0.25mm

 

[badboy6120]

Hi dear manoj
I use T106-2 core with 60 turns of 0.75 wire and 3uf output cap and with these value the output signal is the cleanest and the sound is so clean
as I said before by increasing the 1K resistor I can increase the frequency, so I go higher than 1K and now I have 250kHz frequency
do you think that there might be some problem with my amp?
I ordered T157-2 and I will be using it for my 800W amps

I'll appreciate your help

 

[manojtm]

T106-2 core with 60 turns

47uH it is too high(not bad) use 33uH or 22uH it is good( you will get more current on output)22uH is best.

I get about 250KHZ with 1kohm resistor(lower value will decrease frequency)

Yes. (for better reliability use below 1K. otherwise unwanted oscillation will occur.)

Regards
MANOJ

 

[badboy6120]

Yes. (for better reliability use below 1K. otherwise unwanted oscillation will occur.)

even if it means lower frequency like 130khz???

 

[manojtm]

Hi,

for L use T157-2 core 1.5mm wire 49T (22uH)

Sorry typing mistake

T157-2 core 1.5mm wire 40T = 22uH
T157-2 core 1.5mm wire 49T = 33uH

Regards
MANOJ

 

[manojtm]

it means lower frequency like 130khz???

No. ex... if you get fsw like 500Khz on 1k, reduce the the value 1k to 580 then you will get @350KHz~420KHz

Regards
MANOJ

 

[badboy6120]

No. ex... if you get fsw like 500Khz on 1k, reduce the the value 1k to 580 then you will get @350KHz~420KHz

Regards
MANOJ

with 1K I get about 185Khz and If I ge higher Like 1.5K it will go up to 250Khz
I I go higher it decrease frequency further more like 135Khz

 

[manojtm]

with 1K I get about 185Khz and If I ge higher Like 1.5K it will go up to 250Khz

for getting highest freq. it should be a good components,FB resistor with respect to supply voltage, coil and PCB

Regards
MANOJ

 

[manojtm]

Hi,

* those are important components

Regards
MANOJ

 

[badboy6120]

Hi,

* those are important components

Regards
MANOJ

thank alot dear Manoj

I will try to get higher frequency by using better component and will report back

 

[thimios]

Hi,


Sorry typing mistake

T157-2 core 1.5mm wire 40T = 22uH
T157-2 core 1.5mm wire 49T = 33uH

Regards
MANOJ

If this is a T157-2 1.5mm wire 35T=21μH.
What i missing?

 

[badboy6120]

If this is a T157-2 1.5mm wire 35T=21μH.
What i missing?

I think with 35 turns you will get about 17uH

 

[thimios]

I think with 35 turns you will get about 17uH

This is,according to measured value, 21uH but the question is how i can add more turns to reach the 33uH?
Using a thinner wire or adding a second layer?

 

[badboy6120]

This is,according to measured value, 21uH but the question is how i can add more turns to reach the 33uH?
Using a thinner wire or adding a second layer?

How much power are you going for?

 

[thimios]

How much power are you going for?

I will use a +/-50v power supply.