Powering LM3886 with 12V Batteries

VoLCoM · 14th March 2004, 06:07 PM

Is there a way to power a LM3886 Amplifier with a single...or two 12V battery by using transformers or something like that... because i'm building a subwoofer amplifier for my car... everything is soldered on the board but i need to power it up with 12 volt
i use the Minimized GainKlone Schematic with a +V and -V and GND

Thanks
-Guillaume

medum · 14th March 2004, 06:19 PM

You could either use 2 x 12V batteries in series with the ground in the connection between the two batteries or you could use a 12V DC to 230V AC converter and build yourself a trad. PS for the amp.

soundNERD · 15th March 2004, 01:15 AM

Yes, I would reccommend the two batteries, since you don't lose current when raising voltage with the transformer.

how professional amps work i think is they have a switching (pronounced "complicated"

) power supply to create a positive and negative supply voltage.

Just so you know, the 3886 isn't going to do much damage to your ears. I would reccommend two in bridged mode, but most car subs are 4-ohm so that wouldn't work. maybe two in parallel unless your speaker is 8-ohm.

-Mike

HDTVman · 15th March 2004, 01:22 AM

You will also have the problem that the 3886 has circuitry that shuts it off when the voltage drops to 12 volts. That chip need / wants +/- 20 volts (40 volts difference) to +/- 40 volts (80 volts difference). If you want to use this in a car I would think that a amp chip designed for automotive audio would be a much better choice.

Later BZ

soundNERD · 15th March 2004, 01:24 AM

alternators produce around 14 volts

soundNERD · 15th March 2004, 01:25 AM

or 4 batteries in a row, +-24V

HDTVman · 15th March 2004, 01:25 AM

Untill you stop at a light with the lights and heater fan on.

VoLCoM · 15th March 2004, 01:30 AM

i tougt there was a way to do it with diodes ... would it work?

or i'll have to add a second battery to get the 24volt? or i need batteries to get +24 and -24??

promitheus · 15th March 2004, 01:30 AM

To get a power supply like that you have to make a switched power supply which would cost a lot more money than the amplifier itself.

tool49 · 15th March 2004, 01:38 AM

Actually, the inverters currently sold at canadian tires (or any local store that carry that kind of stuff) might be the easiest way to go. A 400W inverter should be more than enough to power your 3886 and at 59$ it is most likely to be cheaper than the cost of adding a battery and charging circuit for it. Of course you incur more power loss than a 12V power supply circuit but it should not be THAT bad.

I also agree with promitheus about the switcher.

Sébastien

14th March 2004, 06:07 PM	#1
VoLCoM diyAudio Member Join Date: Apr 2003 Location: Saint-Hubert , Quebec	Powering LM3886 with 12V Batteries Is there a way to power a LM3886 Amplifier with a single...or two 12V battery by using transformers or something like that... because i'm building a subwoofer amplifier for my car... everything is soldered on the board but i need to power it up with 12 volt i use the Minimized GainKlone Schematic with a +V and -V and GND Thanks -Guillaume

15th March 2004, 01:22 AM	#4
HDTVman diyAudio Member Join Date: Aug 2001 Location: Chicago area	You will also have the problem that the 3886 has circuitry that shuts it off when the voltage drops to 12 volts. That chip need / wants +/- 20 volts (40 volts difference) to +/- 40 volts (80 volts difference). If you want to use this in a car I would think that a amp chip designed for automotive audio would be a much better choice. Later BZ __________________ What ever makes the tunes flow

15th March 2004, 01:25 AM	#7
HDTVman diyAudio Member Join Date: Aug 2001 Location: Chicago area	Untill you stop at a light with the lights and heater fan on. __________________ What ever makes the tunes flow

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
How to run an AC mic pre from batteries	oaks	Power Supplies	6	17th October 2009 06:02 AM
GC and batteries psu	Ilianh	Chip Amps	40	5th October 2009 01:30 PM
SLA batteries for UcD amp PS	Paul Ebert	Class D	0	16th November 2004 04:53 PM
3 pin li-ion batteries	Holger Barske	Parts	1	12th May 2004 07:54 PM
How long will 9V batteries last for powering opamps?	PaulHilgeman	Parts	4	28th February 2003 04:05 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

14th March 2004, 06:19 PM	#2
medum diyAudio Member Join Date: Dec 2003 Location: Jutland, Denmark	You could either use 2 x 12V batteries in series with the ground in the connection between the two batteries or you could use a 12V DC to 230V AC converter and build yourself a trad. PS for the amp.

15th March 2004, 01:15 AM	#3
soundNERD diyAudio Member Join Date: Sep 2003 Location: Illinois	Yes, I would reccommend the two batteries, since you don't lose current when raising voltage with the transformer. how professional amps work i think is they have a switching (pronounced "complicated" ) power supply to create a positive and negative supply voltage. Just so you know, the 3886 isn't going to do much damage to your ears. I would reccommend two in bridged mode, but most car subs are 4-ohm so that wouldn't work. maybe two in parallel unless your speaker is 8-ohm. -Mike

15th March 2004, 01:24 AM	#5
soundNERD diyAudio Member Join Date: Sep 2003 Location: Illinois	alternators produce around 14 volts

15th March 2004, 01:30 AM	#8
VoLCoM diyAudio Member Join Date: Apr 2003 Location: Saint-Hubert , Quebec	i tougt there was a way to do it with diodes ... would it work? or i'll have to add a second battery to get the 24volt? or i need batteries to get +24 and -24??

15th March 2004, 01:30 AM	#9
promitheus diyAudio Member Join Date: Jan 2001 Location: Germany	To get a power supply like that you have to make a switched power supply which would cost a lot more money than the amplifier itself.

15th March 2004, 01:38 AM	#10
tool49 diyAudio Member Join Date: Apr 2003 Location: Montreal	Actually, the inverters currently sold at canadian tires (or any local store that carry that kind of stuff) might be the easiest way to go. A 400W inverter should be more than enough to power your 3886 and at 59$ it is most likely to be cheaper than the cost of adding a battery and charging circuit for it. Of course you incur more power loss than a 12V power supply circuit but it should not be THAT bad. I also agree with promitheus about the switcher. Sébastien

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read