DIY solar powered boombox - Page 2

v-bro · 20th May 2007, 08:59 PM

41hz AMP6 has over voltage protection...

I saw flexible solar panels at http://www.conrad.nl They seem very nice for portable use...

Pano · 20th May 2007, 11:03 PM

Well... I didn't want to use a battery, that would be cheating! :P

For practical reasons, yes, a battery would be great. But I wanted to hear pure solar music. It was fun. And very, um, illuminating.

With the very little power that these panels produce, 1.5 watts each, you are running right on the edge. If you turn up the sound too high, the voltage will drop and the amp will cut out. It's interesting to hear where and when in the music this happens. Too much bass or a loud midrange passage and the amp will cut out. The cut off point is about 8 volts on the supply.

Adding the large stiffener cap helped bring up the overall level because the cap helped fill in the peaks. The panels can supply the average current, the cap acts as a reservoir for the peaks. Thus overall level can go up.

Running 2 panels:

In my first post I warned of running 2 panels in parallel because of the over-voltage. Very true in the midday Tropical sun. But it turns out that as the day wore on and the sun dropped, I HAD to use 2 panels. And I went to an amp without the diode, so no 0.6 volt loss.
In the afternoon the voltage was holding at 12V with 2 panels for moderate levels. But the panels had to be tilted to face the sun. The changing angle of the sun made a big difference in how much power came out of the panels.

You would certainly want the most efficient speakers you can carry. It's going to make a big difference in how much SPL you can get. Maybe some efficient car speakers?

Over all, a lot of fun. Having just enough power to get by is a great teacher. It lets you hear the results right away. Things you may already "know" about power supplies become very obvious here. When the amp cuts out, there isn't much doubt that you don't have enough current!

I want to thank Pekar again for starting this thread and his project. I've wanted to do this for years, he inspired and helped me to get it done. =) A recommend project, if for nothing more than the educational fun.

v-bro · 21st May 2007, 12:19 AM

http://www.fvgenergy.com/photovoltai...ovoltaics.html
http://store.altenergystore.com/Sola...er-Pack/p2380/
http://store.altenergystore.com/Sola...r-Panels/c679/

They're not on the conrad site at the moment...

Note they're extremely light as well

zacster · 22nd May 2007, 02:26 AM

I read the thread a little more closely and now I know where the confusion is with my post and the reply.

I'm looking into putting a full fledged solar system into my house, and you're talking about a small portable panel. So I could power a 24v tube pre-amp without any problem on my house system, but maybe not on the portable panel.

I'm trying to get someone to come and give me an estimate for the solar installation. They must all be very busy because I can't get anybody.

Saturnus · 3rd June 2007, 09:55 AM

I just ordered 4 of these for my 41hz amp6-basic project:

http://www.siliconsolar.com/8V--250-p-16533.html

I plan to serial and parallel connect them to get 16V output to recharge my 12Ah SLA.

These new modules from silicon solar are just perfect for DIYers. Fully encased, solder pads on the back, 4mm thick, and a great variety of modules.

stoolpigeon · 3rd June 2007, 11:10 AM

Pekar - great post and great website.

Checkout the post on making ferrofluid.

This stuff is fun. Remember when audio was fun?

kartino · 7th June 2007, 11:27 PM

Great! ..... next will be wind powered or nuclear powered amps :-)

v-bro · 8th June 2007, 12:37 AM

Quote:

Originally posted by G4ME
what about a solar paneled flash light?

Hahah, what about a wheel driven by an electromotor powered by a generator spun by the wheel?

No seriously I want to use solarpower soon as well. Create a charger/protection and continuous output device for a 12V system at home and on the road. Many other things (like warm-white led lamps) can run on this supply as well. The batteries won't have to be very big to keep your house lit all night

Than perhaps a laptop, all my audio, maybe even convert a PC to run on 12Vdc (I've seen PSU boards to run a PC from 10 to 30Vdc batteries!).

kartino · 8th June 2007, 01:06 PM

Hi,

I agree with you, v-bro. This is not a joke, sometime you will be at the place without power grid at all.

But what panomaniac did was not a good idea for me. What is the purpose with playing the voltage drop with music level? Not for me, I will not waste my money. I will spent my money for a good music of course.

Pure solar powered? Fine, use enought parallel solar board and regulate the output. That is more reasonable. Well, good luck anyway.

kec · 8th June 2007, 02:46 PM

Quote:

Originally posted by v-bro
Hahah, what about a wheel driven by an electromotor powered by a generator spun by the wheel?

How about hamster power

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.

Nice job Pekar!

-Ken

20th May 2007, 08:59 PM	#11
v-bro diyAudio Member Join Date: May 2006	41hz AMP6 has over voltage protection... I saw flexible solar panels at http://www.conrad.nl They seem very nice for portable use... __________________ Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......

20th May 2007, 11:03 PM	#12
Pano diyAudio Moderator Join Date: Oct 2004 Location: SW Florida	Sundown Update Well... I didn't want to use a battery, that would be cheating! :P For practical reasons, yes, a battery would be great. But I wanted to hear pure solar music. It was fun. And very, um, illuminating. With the very little power that these panels produce, 1.5 watts each, you are running right on the edge. If you turn up the sound too high, the voltage will drop and the amp will cut out. It's interesting to hear where and when in the music this happens. Too much bass or a loud midrange passage and the amp will cut out. The cut off point is about 8 volts on the supply. Adding the large stiffener cap helped bring up the overall level because the cap helped fill in the peaks. The panels can supply the average current, the cap acts as a reservoir for the peaks. Thus overall level can go up. Running 2 panels: In my first post I warned of running 2 panels in parallel because of the over-voltage. Very true in the midday Tropical sun. But it turns out that as the day wore on and the sun dropped, I HAD to use 2 panels. And I went to an amp without the diode, so no 0.6 volt loss. In the afternoon the voltage was holding at 12V with 2 panels for moderate levels. But the panels had to be tilted to face the sun. The changing angle of the sun made a big difference in how much power came out of the panels. You would certainly want the most efficient speakers you can carry. It's going to make a big difference in how much SPL you can get. Maybe some efficient car speakers? Over all, a lot of fun. Having just enough power to get by is a great teacher. It lets you hear the results right away. Things you may already "know" about power supplies become very obvious here. When the amp cuts out, there isn't much doubt that you don't have enough current! I want to thank Pekar again for starting this thread and his project. I've wanted to do this for years, he inspired and helped me to get it done. =) A recommend project, if for nothing more than the educational fun. __________________ Take the Speaker Voltage Test!

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21st May 2007, 12:19 AM	#13
v-bro diyAudio Member Join Date: May 2006	http://www.fvgenergy.com/photovoltai...ovoltaics.html http://store.altenergystore.com/Sola...er-Pack/p2380/ http://store.altenergystore.com/Sola...r-Panels/c679/ They're not on the conrad site at the moment... Note they're extremely light as well

22nd May 2007, 02:26 AM	#14
zacster diyAudio Member Join Date: Dec 2003 Location: NYC	I read the thread a little more closely and now I know where the confusion is with my post and the reply. I'm looking into putting a full fledged solar system into my house, and you're talking about a small portable panel. So I could power a 24v tube pre-amp without any problem on my house system, but maybe not on the portable panel. I'm trying to get someone to come and give me an estimate for the solar installation. They must all be very busy because I can't get anybody.

3rd June 2007, 09:55 AM	#15
Saturnus diyAudio Member Join Date: Jun 2005 Location: Copenhagen, Denmark	I just ordered 4 of these for my 41hz amp6-basic project: http://www.siliconsolar.com/8V--250-p-16533.html I plan to serial and parallel connect them to get 16V output to recharge my 12Ah SLA. These new modules from silicon solar are just perfect for DIYers. Fully encased, solder pads on the back, 4mm thick, and a great variety of modules.

3rd June 2007, 11:10 AM	#16
stoolpigeon diyAudio Member Join Date: Feb 2007 Location: Laputa	Pekar - great post and great website. Checkout the post on making ferrofluid. This stuff is fun. Remember when audio was fun?

7th June 2007, 11:27 PM	#17
kartino diyAudio Member Join Date: Feb 2005 Location: Gunungkidul Indonesia	Great! ..... next will be wind powered or nuclear powered amps :-)

8th June 2007, 01:06 PM	#19
kartino diyAudio Member Join Date: Feb 2005 Location: Gunungkidul Indonesia	Hi, I agree with you, v-bro. This is not a joke, sometime you will be at the place without power grid at all. But what panomaniac did was not a good idea for me. What is the purpose with playing the voltage drop with music level? Not for me, I will not waste my money. I will spent my money for a good music of course. Pure solar powered? Fine, use enought parallel solar board and regulate the output. That is more reasonable. Well, good luck anyway.