Looking for a PCB or layout for an LME49830 amp

[pebo]

Hi,

are there PCB or layout files for an LME49830 amplifier? Beside the boards offered by CP Design, which has no price information on its web site at the moment ("under construction").



Peter

 

[jackinnj]

Did you look on the data-sheet? Just take their layout for the demo board.

 

[si_jopie0382]

I hope this is help

"http://www.chip-pcb.cn/en/M-9830-A.htm"

 

[SpittinLLama]

If you want what is shown in the application note (AN-1850) then just go to National's site and download the Gerber files. Here is the link:

http://www.national.com/analog/audio/pwramps_evaluation_boards

-SL

 

[jackinnj]

Aren't the diagrams of the board shot at 100% ? -- if so you can print the adobe file on overhead transparency material, and, using some photosensitive board -- burn your own PCB's in a bout an hour. this is what I do.

Even if the diagrams are not shot at 100% you can use the scale feature in adobe acrobat to print to your desired magnification.

 

[pebo]

Thanks

Hi


thanks a lot for your replies. I think I will give the gerber files a try first.

Peter

BTW: CP Design's PayPal Chart will be operational until end of the week they informed me.

 

[tnargs]

If there was to be a GB for the PCB in AN-1850, I would join up.

It's a pretty darned exciting and highly flexible circuit, should suit many DIY people.

I can't figure out if the chip-pcb offering is the full schematic from AN-1850, or "similar". The layout is definitely different.

 

[floeper]

Hi All,

i just bought 2x amp kit second hand, the board is from cp design. it has 1 lme49830 and 4xirfp9240 and 1x c5171. I have 2x PSU for these amps as well.

I'm looking for more info regarding supply voltages. PSU has caps rated at 71V, according to ti info +-65VDC is recomanded. can anybody help me? I cannot find any info with google. only other lme49830 designs pop up.

Thanks,

Coen

 

[AndrewT]

I don't know of any electrolytic capacitors rated @ 71V ("PSU has caps rated at 71V,")

They are generally available in 63V, 75V, 80V and 100V ratings for long term use.
Each manufacturer has ratings for slight overload for the short term and again overload rating for very short term transients.

You choose the transformer you need to meet your power output requirements.
From there you can calculate or measure the worst case voltages out of the PSU.
You buy capacitors that are rated higher than the worst case highest output voltage.

 

[floeper]

i checked, 71V is noted on the caps themselfs.

But what kind of transformer do I need for this amp?
2x46VAC 500VA per amp module (gives me 2x 65VDC), but I also need secondary voltage supply, how many would that be?

 

[AndrewT]

I think you will find that the 46Vac transformer will give a lot more voltage than 65Vdc after passing through the rectifier.

 

[floeper]

Why is that? The formule is VAC x 1.41 = VDC right?

 

[AndrewT]

No.
Vout = Mains Voltage / Rated primary voltage * Rated secondary voltage * {1+ transformer regulation}
Then apply sqrt(2) to find the peak voltage that is applied to the rectifiers.
The smoothing tries to store the voltage after the rectifiers.

And after you do all that then find out what your maximum mains voltage is and re-do all your predictions.

You may find that your 71V capacitors are way overvoltage.

 

[floeper]

Caps are, Elna la4 71V 18000uf (m) ce 85°C
These PSU's are already soldered. So they are as they are. The amp kit I still need to solder.

Do you have any idea what voltages I need for this amp based on the lme49830?