diyAudio (
-   Solid State (
-   -   Trying to build a small battery powered amp... (

James39 29th October 2009 11:03 PM

Trying to build a small battery powered amp...
Hi there, sorry if this is the type of thing that has been discussed before (I searched but didn't see anything) or if this is in the wrong field.

I'm a nut for stupid little projects, and am looking to expand on one I did a while back. I had put some ammo crates from an army surplus store onto my bike for storage, but never use them for more than holding some spare tubes and whatnot. Upon finding some old speakers I tossed in storage a few years back, I decided to take on the project of building them into these ammo crates and running up to an MP3 player on the handlebars as a bit of a novelty for large group rides I participate in. Obviously, I want it to be self contained in crates, so size is somewhat of an issue; though that's mostly going to lie with the batteries and speakers themselves.

Being the clichéd broke college students, I'm doing this with as many found parts as possible. I have access to a pretty large array of resistors, small capacitors, diodes, leds, etc. thru my school and the electronics lab at my work; so my main concern is just to avoid any specialized parts and to use a design that is optimal for the speakers I have.

The speakers are just some crappy Insignia ones, and are marked as being 5-40W with 8ohms impedance. I can solder well and have taken enough classes on electronics to follow a schematic, but I have fairly little knowledge that actually applies to my project. While searching I've seen a handfull of schematics for small amps, but they always want more power than I can get with the space I have for batteries.

Where do I start?


tomtt 30th October 2009 02:21 AM

pictures of the speakers ...

col 30th October 2009 04:04 AM

Just get a Lepai TA2020 off of Ebay and a 12v SLA. Don't charge it over 13.2v though.


James39 30th October 2009 05:22 AM


Originally Posted by tomtt
pictures of the speakers ...

These are the speakers.

Insignia® - 3-Way Indoor/Outdoor Speakers (Pair) - IS-SP3WAY


Originally Posted by col
Just get a Lepai TA2020 off of Ebay and a 12v SLA. Don't charge it over 13.2v though.

I'm looking to build something myself for the fun/challenge of it. Plus, I just started taking courses geared towards switching my major to electrical engineering, so I'd like to get some experience. And, above all, I have no money to buy anything, even if it is cheap.

Thanks for the suggestion, though. If I do end up giving up on building my own, that looks like a pretty good option.

GK 30th October 2009 06:07 AM


Originally Posted by James39 (
Where do I start?

With an LM380N

Richard Ellis 30th October 2009 06:30 AM

For only Twenty bucks or so, you can get what you want....Try here.
You should be able to build it no'll HAVE to spend something.

__________________________________________________ _______Rick......

All times are GMT. The time now is 12:02 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2