OT: LED lighting configuration...

Bill Sudbrink wh.sudbrink at verizon.net
Fri Apr 29 15:10:16 CDT 2016

Paul Koning wrote:
> > On Apr 29, 2016, at 3:32 PM, Bill Sudbrink <wh.sudbrink at verizon.net>
> wrote:
> >
> > ... The "bulbs" are labeled:
> >
> > 15F18120-45 15 watt 36vdc constant current
> >
> > I'd like to put four in a fixture and I'm trying to
> > understand what kind of driver I need and how to wire
> > it.  I was thinking of using a Mean Well LPF-60D-36
> > like this:
> >
> > http://www.ebay.com/itm/Mean-Well-LPF-60D-36-AC-DC-POWER-SUPPLY-
> Dimmable-LED
> > -DRIVER-36V-60W-CLASS2-
> /161857068172?hash=item25af6edc8c:g:9hQAAOSwA4dWHVn5
> >
> > and wiring the "bulbs" in parallel to it.  But after
> > realizing that I'm not completely sure what a "constant
> > current" power supply does and doing a little "googling"
> > I don't know if that's the right approach.
> A constant current supply is one that delivers a constant
> current to a varying load (within limits) just as a constant
> voltage supply delivers a constant voltage to a varying load.

Ok, I figured that much.  The problem/question is why there
are no Amp ratings on anything?  Assuming the DC equation:

Watts = Amps X Volts

I want a constant current supply that "pushes" 0.41 Amps.
A little more googling reveals that the above supply is
rated "1.67A output".  This seems to support the W=AV
theory.  So, do I want a PS labeled "15 watt 36vdc",
regardless of how many bulbs I want to drive?  You say
"within limits".  What specification do I look for to
understand the limits?


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