For an art project I'm working on that will take place outdoors, I would like to create a poetry listening spot. The concept involves constructing a monument with a speaker driver and a button (or a distance sensor, which I have not yet decided on) to play back poetry.
I intend to use this board for both audio playback and processing the button press/distance sensor input.
What I'm currently trying to figure out is:
Which audio amplifier and driver should I use? For a previous project, I received helpful suggestions and used a specific driver and amplifier that worked very well. Would these be suitable choices for the current project?
Powering the system – the entire setup should run on solar power and a battery. I am open to any suggestions on this matter. The installation is scheduled for release in the summer when plenty sunlight is available. However, I also want it to function during the winter when there are fewer sunny days and rainfall is more likely.
To determine the appropriate solar panel and battery for the system, I can assume that the setup will operate for approximately one hour per day. The board responsible for playing back the poetry consumes 110mA, and the amplifier will use a maximum of 30W, although it is likely to be much less.
In order to size a solar power/battery system, you should first decide on the battery voltage. 12V is common as lead acid batteries take a lot of abuse and do not require finicky chargers.
Then, measure the average current draw in Amperes of the setup over one full day (or several). Estimate the average current usage in Ampere-hours (Ah) per day, needed if it is shut off for periods, like night. Energy usage is Ah*12V in watt hours.
For continuous operation on cloudy days, you need a a battery with sufficient capacity so that it can supply that many Ah over the longest expected period of no sun.
For the battery to charge in one sunny day (say 8 hours of direct sun), the solar panel needs to provide 12V at current roughly equal to (battery Ah)/8.
My system has two loads that require power. one is the wavtrigger board that should be power from 9V power source and the other is the audio amplifier that will require 12V.
the wav trigger will consume 110mA - from its manual:
At 9VDC, the WAV Trigger draws about 80mA when idle and on average about 110mA when
playing tracks
and the audio amplifier assuming 30W at 12V is 2.5A
so we could say that the system needs 2.61A in order to functioning?
That is a reasonable start at estimating the maximum power draw.
The amplifier will consume 2.5 Amperes only if it is feeding appropriate speakers, capable of that amount of power, with the volume is cranked up all the way.
Nothing beats using your multimeter or recording current monitor to actually measure the average power consumption over a reasonable period of time.
is this battery charger board will work with 12V solar panel to charge 12V battery?
or the input voltage must be higher then the desired output voltage?
I have been waiting, in the UK, for a couple of weeks, (14 days) to test a small solar powered Arduino, but there has been very little direct sun in that period, maybe 12 hours in total. The rest of the time its been cloudy or raining during which times I was only getting 10-20% of the solar panels rated output.
If I were planning your project, I would assume the average solar panel output was only 20% of the direct sun value and for 8 hours a day.
my calculation is that the system will be used no more then 1 hour a day. lets take a margin gap and say it will be used 2 hour a day. that's put us with 5Ahr
