Re: 12v adapter for lights

On Mar 7, 12:50 pm, cl...@xxxxxxxxxxxx wrote:
On Sat, 07 Mar 2009 04:26:43 GMT, aemeijers <aemeij...@xxxxxxx> wrote:
gfretw...@xxxxxxx wrote:
On Sat, 07 Mar 2009 03:47:19 GMT, aemeijers <aemeij...@xxxxxxx> wrote:

Nearest goodwill or salvation army store- look through the row of stuff
that plugs in, and you can probably find a suitable transformer for less
than five bucks.  May have to buy the whole item to get it, but at that
price, who cares?

I doubt you are going to find a 5a transformer at Salvation Army.

Those bricks that came with the HP printers for years and years weren't
5 amps?
(Don't feel like digging out my crate of mostly-trashpicked transformers
to check right now.)

Upon due reconsideration, I now lean more toward just trashing the
thing. I may be a cheap SOB, but life is too short (and precious) to try
MacGyvering something that can kill you. Fresh puck lamps or whatever
with UL stickers just aren't that expensive.

 Get a power supply for outdoor garden lights Constant duty, high
output, and readily available (even at the "borg").
AC oputput is fine.- Hide quoted text -

- Show quoted text -

Three 20 watt lamps = 60 watts. The step-down transformer rated at
57.5 watts. (5 amps x 115 volts = 57.5) maybe underrated from the
start? Depending on safety factor (if any?) if your voltage sometimes
a bit high, say 120 volts (which ours sometimes is) then;
120/115 a 60 = 63 watts approx. That's a 9% overload right there.
Other suggestions cut back to three 15 watt amps, or eliminate one
lamp, or use LED replacements (if suitable).
Better still get rid of the extra 12 volt gadgetry and use 115 volt
lighting fixtures.
BTW congratulations on the grasp of volts, amps and watts.
Using the Formula Volts x amps = watts. (And conversely Watts/volts =
amps).
Think on this;
60 watts of lamps at 120 volts will need 0.5 amps. That's a relatively
small current flow.
60 watts of lamps at 12 volts will conduct 5 amps. That's same amount
of power (watts) but ten times the current at one tenth the voltage.
Five amps is a heavier current so wiring fixtures, lamps sockets and
the transformer must be capable of handling the heavier current flow,
continuously.
.

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