On 1/14/15 11:52 AM, Jack Brindle wrote:
LED bulbs have power supplies which convert 120/240VAC down to the DC level
needed by the LEDs. These components are the major failure point (for CFLs as
well). These are high current power supplies that generate quite a bit of heat
and thus require at least some of that heat sink capacity as well.
True for replacement bulbs for replacing standard Edison base
incandescent, like the ones you get at home depot.
Not necessarily true for a specialized application. If you were
replacing ALL the bulbs in a tower, there's nothing stopping you from
having a big constant current source at the base, like they do with
streetlights.
It's sort of like replacing incandescents with strobes..
So what kind of climbing harness is required when changing the external
aircraft bulb at altitude??? :-)
- Jack B, W6FB
On Jan 14, 2015, at 10:55 AM, Hans Hammarquist via TowerTalk
<towertalk@contesting.com> wrote:
Replacing a bulb on an aircraft is 'slightly" easier than climbing 1500 feet.
Regarding temperature; the LED do not suffer as for example the florescent
lights. If I remember it right LE-s work better at lower temperatures, the
light output goes down as the temperature increases. You notice that LED bulbs
are equipped with rather large heat sinks, needed to keep the LED diodes to
work properly.
Hans - N2JFS
-----Original Message-----
From: Roger (K8RI) on TT <K8RI-on-TowerTalk@tm.net>
To: towertalk <towertalk@contesting.com>
Sent: Tue, Jan 13, 2015 5:16 pm
Subject: Re: [TowerTalk] Fwd: Now THIS is a tower climb!
There already are, very bright LED strobes in use on aircraft. All the
exterior lights on mine were solid state, except for the landing light.
There are LEDs that could have replaced that, but I never saw any that
had been approved.
I don't know at how low a temperature they will still function, but I
flew in temperatures a lot colder than most towers would see.
I would think the new LED strobes would be ideal for towers and
replacements would be few and far between.
73
Roger (K8RI)
On 1/13/2015 12:25 PM, Hans Hammarquist via TowerTalk wrote:
I think the problem is to introduce a "new", long-life, light bulb. Any,
modern LED bulb would do lifetime wise. I believe, though, there are several
light bulbs in the assembly that automatically replace the bulbs as they burn
out. That is used in lighthouses to insure there is a light on all the time. To
design an assembly that could automatically replace burnt-out LED bulbs might
not be that simple. You know, everything there has to be approved by
authorities.
Hans - N2JFS
-----Original Message-----
From: Richard Solomon <dickw1ksz@gmail.com>
To: Tower Talk <towertalk@contesting.com>
Sent: Mon, Jan 12, 2015 6:39 pm
Subject: Re: [TowerTalk] Now THIS is a tower climb!
Repairs ??
Looks like he's changing a light bulb !!
Now, invent a really long life bulb and you will sell at least a hundred !!
73, Dick, W1KSZ
On Mon, Jan 12, 2015 at 4:33 PM, Mike via TowerTalk <
towertalk@contesting.com> wrote:
This is video of a technician climbing 1768 feet to the top of a
transmissions tower for repairs.
It also shows him free climbing and some dialog to go along with it.
Its a helmet cam so if anyone gets dizzy or has anything that can give out
watching this stuff while sitting in your chair....be warned!...DO NOT
WATCH IT!!
https://www.youtube.com/watch?v=INbKYq0G9nU
Mike W2GR
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