LM3386 battery powered?

[Freedom666]

Hello,

I am not a technician. I bought a LM3886 design in Stereo with the board from chipamp.com as used hifi from a friend. It worked nice.

I turned it into a battery powered design (24 Volt with two 12 V in series) without knowing about PG+ and PG- and have put a battery on V+ and V- but the amp does not work. It gives music for a second and then mutes.

Can anyone tell me if this design can be run with batteries? Or do I have to reinstall the transformer? (What is a pity for me)

I'd like to check the sound with batteries as I have another gainclone which runs very perfect with 12 Volts. Google "Toxic TX 100" (identical with "SilverStar 300") it has the TA8210 chip and sounds really nice with changed Electrolytics i.e. Panasonc FCs. I heard about the better chips like lm3886 and want to try it out.

Bye, Freedom666

PS: I searched a long time for a thread concerning turning this design into battery powered version but did not find anything.

[BrianGT]

Originally posted by Freedom666
Hello,

I am not a technician. I bought a LM3886 design in Stereo with the board from chipamp.com as used hifi from a friend. It worked nice.

I turned it into a battery powered design (24 Volt with two 12 V in series) without knowing about PG+ and PG- and have put a battery on V+ and V- but the amp does not work. It gives music for a second and then mutes.

Can anyone tell me if this design can be run with batteries? Or do I have to reinstall the transformer? (What is a pity for me)

I'd like to check the sound with batteries as I have another gainclone which runs very perfect with 12 Volts. Google "Toxic TX 100" (identical with "SilverStar 300") it has the TA8210 chip and sounds really nice with changed Electrolytics i.e. Panasonc FCs. I heard about the better chips like lm3886 and want to try it out.

Bye, Freedom666

PS: I searched a long time for a thread concerning turning this design into battery powered version but did not find anything.

The amplifier needs a ground reference to work. An optimal battery setup would be to put 2 batteries in series from +PG to +V and 2 batteries in series from -V to -PG.

For your existing setup, connect one battery across +PG to +V and the other from -V to -PG, and you should be able to get it to work.

[eketehe]

Nice =), i will also try,
Mr brian, hope you have a suggestion hows to (re)charge the 2 serial battery in car,which are generaly 12V?
Hope we can skip an inverter,.. Thks

[eketehe]

One more thing, if i'm not wrong,that sud be 12-0-12vdc, is it sufficient? Or we have to change to schematic to single supply application,without battery centre ground.
Brgds

[eketehe]

Oops, i'm sorry.. You mean 4 batteries? Oh, no thanks =) pls ignore my last post

[BrianGT]

Originally posted by eketehe
Oops, i'm sorry.. You mean 4 batteries? Oh, no thanks =) pls ignore my last post

2 batteries should provide a working amplifier, but you might not get the desired output levels without using 4 batteries. I would at least test with the 2 batteries that you have on hand, and see how you like it.

Best of luck!

--
Brian

[Freedom666]

Hello,

thanks for the replies. Now I know how to change the wiring.

I have a question. With four batteries won't there be a problem with symmetry? What if one stereo side would have a volt difference? Does this cause any effects?

Is it possible to wire per stereo side three times 12 Volts? I measured three batteries and altogether there is 38 Volts. Would this cause problems with the LM3886 or is it the maximum possible?

Bye, Freedom666

[BrianGT]

Originally posted by Freedom666
Hello,

thanks for the replies. Now I know how to change the wiring.

I have a question. With four batteries won't there be a problem with symmetry? What if one stereo side would have a volt difference? Does this cause any effects?

Is it possible to wire per stereo side three times 12 Volts? I measured three batteries and altogether there is 38 Volts. Would this cause problems with the LM3886 or is it the maximum possible?

Bye, Freedom666

You will want to balance the rails for the amplifier, meaning that you should either use 2 batteries, or 4 batteries. The three batteries will cause unbalanced rails, which won't let you drive the amplifier any harder than if you are just using 2 batteries.

--
Brian

[Freedom666]

Hello Brian,

maybe my english ist not good enough.

I understood well that i have to use for left and right channel separated batteries i.e. 2x12 Volts for left and right channel.

My question was if it is possible to drive the LM3886 left and right channel with more Volts of up to nearly 40 Volts.

And I wanted to know if the use of batteries in this design in general could be at the end inappropriate of what concerns the similarity of left and right channel because separated batteries are used. If one battery side would have a volt more then maybe one channel would be louder? Or ist this a typical naive question of a non-technician.

Thanks for your answers so far. I'll test it.

Bye, Freedom666

[danielwritesbac]

Bridge mode and a pair of 12v batteries. . .

Idea: A DPDT on/on switch with the batteries connected on center, amplifier connected on upper, and a pair of RV solar chargers connected on lower. Ha! When you turn the amplifier off, the batteries charge for free.