Sorry forgot to send to list (again!)
On 28/05/10 10:13, Jörn Nettingsmeier wrote:
On 05/27/2010 06:36 PM, Bob van der Poel wrote:
A friend
of mine was talking about how he would like to be able to
busk with
his keyboard, and I said I would look into the possibility of
building him a
battery powered PA for it. Does anyone have any suggestions for good
ways of
going about this? We would like to keep the cost as low as possible.
How about an off-the-shelf UPS? Don't know how big you'd need, would
depend on the gig time, etc. There is probably a way to calculate that
:)
The consumer UPS units I've see all have lead-acid (sealed) batteries
and are quite reliable.
not really recommendable for a permanent setup. with an ups and
standard mains equipment, you will waste battery (and carry dead
weight) twice: in the inverter that generates grid voltage from the
battery, and in the PSUs of your gear that will re-transform the
precious grid voltage back into low-voltage DC. throw out the middle man.
I think we actually need an inverter anyway, because my friend's
keyboard has a low voltage AC input, not DC, so it would be hard to
generate that from 12v DC directly.
What I'm thinking of doing is to have the amp running directly from DC,
using a cheap car amp, but also have an inverter to power the keyboard
and the effects boxes he uses.