Ruby amp with solar power

[Kain]

Hi,

I want to build ROG Ruby amp with solar power to my uncle as a 60 yr birthday gift. Do you think the panel below is enough?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220430471471

or maybe these
http://cgi.ebay.com/mini-solar-panel-9v-2w-solar-power-6v-battery-led-light-/320517831575?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item4aa059fb97

http://cgi.ebay.com/9V-200mA-1-8w-Solar-Panel-160X100mm-/260634610778?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item3caf088c5a

If not, could you please direct me to the right size panel. Thank you.

[PRR]

Well, if you want to play in FULL sun, sure, that will work. Will be fading by late afternoon.

Figure an audio power amp driving an 8 ohm load at FULL output as a 50 ohm resistor.

At various voltages it will pull:
6V - 120mA
9V - 180mA
12V - 240mA

We don't play FULL ALL the time. Some storage (a big cap) will hold excess power until the next big whang. A rockin' ol man might be fine with the 12V 65mA panel with a 22,000uFd 16V cap across it (1 second sag). The 9V/6V 2W (200mA) panel needs no storage at noon, but some storage might keep him plinking closer to dusk.

[richon]

besides:

i just did a LITTLE GEMS MKii , which has 2 x LM386 and the consumption was onli 30,2mA


so those cells would work fine 

[PRR]

> the consumption was onli 30,2mA

The idle current may be like 30mA.

A class AB amplifier has a low idle current plus a Load current when putting out power.

What is the consumption when playing LOUD ?

[Kain]

We don't play FULL ALL the time. Some storage (a big cap) will hold excess power until the next big whang. A rockin' ol man might be fine with the 12V 65mA panel with a 22,000uFd 16V cap across it (1 second sag). The 9V/6V 2W (200mA) panel needs no storage at noon, but some storage might keep him plinking closer to dusk.

Thank you sir. I ordered 15V 65mA 1W panel + 22000uF 16V cap and going to give it a try.

My uncle has hosted quite big ecological/organic music festival on his farm for many years now so I thought this would be The Gift for him.

BTW, can I connect the panel like this (panel output to the 9v jack):



If the sun refuses to shine we can just disconnect the panel and rock on with battery.

And the cap would go between +9VDC to circuit board and GROUND?

[Kain]

Received the panel and wired it up with DC plug straight to Ruby 9V in.

Jammed last night with the Nordic sunset and it worked ok. However it feeds about 15V to the Ruby and LM386N-1 takes only 12V. Should I need some kind of regulator there? Diode drop could also be an option, but it would possibly shorten the playtime on not so bright days as it will drop the voltage anyway.

[richon]

> the consumption was onli 30,2mA
The idle current may be like 30mA.
What is the consumption when playing LOUD ?

sadly the consumption was 320mA when playing loud


the 2 channel RUBY  (stereo for my ipod, instead of usind 2xLM386 as 1W amp MONO) has a 50mA at loud consumption