LM3886 Schematics + PCB

Hi,


I like to Parallel Super Gainclone, like as mentioned in Parallel LM3886 Diagram using wire wound 0.5 ohm 1 watt resistor (3) per channel and ground with 0.1uf (ceramic or film capacitor) with 2 ohm 1/w metal resistor.


Mile, Prasi can you guys just confirm whether it will work or not.


Thanks in Advance,
Nandhakumar
 
Hi,

I am about to build super gain clone. Waiting for PCB to arrive. Mean time i like to know the power requirements, -+35v what abt amps. How much amp required for single board and what about 5 such boards

Mile, Prasi and others plz help


Thanks,
Nandhakumar
 
Following the datasheet, a single lm3886 can handle 50W cont. avg. output power into a 8Ohm load with supply voltage +-35V --> I = sqrt(P/R) = sqrt(50/8) = 2,5A
So it needs 2,5A continuous current
and 2,5*sqrt(2) = 3,54A peak current


Multiply those values times 5 and you get what 5 of such boards need
 
Following the datasheet, a single lm3886 can handle 50W cont. avg. output power into a 8Ohm load with supply voltage +-35V --> I = sqrt(P/R) = sqrt(50/8) = 2,5A
So it needs 2,5A continuous current
and 2,5*sqrt(2) = 3,54A peak current


C'mon! 2 * 35V * 2.5 A = 175 W. At full output power of 50 watts that would equal to 125 watts of thermal dissipation. Never ever!


Best regards!
 
Yes, dissipation always is input DC power minus output power.

Btw, 1.25 A of DC consumption, which is half of the value that you've calculated, seem to be more reasonable: 35 V * 2 * 1.25 = 87.5 W, minus 50 W output = 37.5 W dissipation. Remember that each half wave only draws current from one rail, not from both simultaneously.

Best regards!
 
Thanks to All

Hi Guys,

Thanks for the help Prasi.

I am looking for power supply design. If possible any one has some good design to feed 35v dual supply with components list then share it to me. It will be a great help for me.


Thanks and Regards,
Namdhakumar
,
 
I did something similar to this.
 

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