sound system for velomobile - help needed

[thedarlington]

from CoffeeLuke: An AC.DC step down works as a DC.DC step down!!! ones with a large input ie.100V-220V will work as low as 40V.then I use $15 pc speakers.

 

[thedarlington]

will running a 5a switcher brick on a 1a amp do any damage?will 3 1a amps be better? or does the 5a need to be fully used? assuming theyre all same 12v requirement, (using 15v since its said its safe) im really interested in running a 15v 5a toshiba power brick but want to know if this is safe while i get the other 4a of amps going, or would it be better to run a small power supply for each one for now?

 

[wojtek]

can anyone elaborate on marty's post about using switcher WALL AC Power Bricks to step down currents? im really interested in this concept but how do you connect it to the battery circuit? do you just hookup one metal wall tab to batt+ and the other to batt- ?

All your music equipment needs power usually 5V or 12V DC. No one believes that you can run most of these 120V AC adapters, off your DC bicycle battery. It does work. I tested a bunch of them with my 48V battery. They all worked. Look what Fechter figured out.
Cheap DC-DC converters for over 60v input.

USB TRAVEL CHARGER
http://www.allelectronics.com/make-a-store/item/PS-223/USB-TRAVEL-CHARGER/1.html
I don't know if this adapter will have enough amps for what you want to do? Need to ask the electricity experts that.

it even works with my 6s lipo packs but not all usb devices are getting charged this way.Some do, some dont

 

[thedarlington]

alright ive just confirmed my 12v 1a speakers do not like even a 12v 1.5a power supply, how are you guys doing it to work with a 15v 5a power supply and have the electronics not reject the voltage? or is there some other type of reducer used from there?

 

[thedarlington]

any1 know how efficient using the wall brick to step down dc is? bc using an inverter isnt recommended for being innefficient but this is a more efficient switcher circuit that 'chops' down voltage and completely different from rel wall bricks from back in the day and inverters

 

[John in CR]

any1 know how efficient using the wall brick to step down dc is? bc using an inverter isnt recommended for being innefficient but this is a more efficient switcher circuit that 'chops' down voltage and completely different from rel wall bricks from back in the day and inverters

Even if it loses 30-40% that's just 4 or 5 watts.

 

[John in CR]

any1 know how efficient using the wall brick to step down dc is? bc using an inverter isnt recommended for being innefficient but this is a more efficient switcher circuit that 'chops' down voltage and completely different from rel wall bricks from back in the day and inverters

Hook it to a battery and see what kind of current it really draws. If you have a second 12V out switcher sitting around unused, try paralleling it with the other if the one is just a bit shy on current.