On 4/26/2010 9:49 PM, The Daring Dufas wrote:
Don Klipstein wrote:
In article , Peter wrote:
On 4/24/2010 9:10 PM, The Daring Dufas wrote:
wrote:
On Sat, 24 Apr 2010 11:57:29 -0400, Peter wrote:
SNIP to here to edit for space
I was able to pull off the rotating shade, unscrew the bulb socket,
pull it out about 2", and observe a 1" glass bulb that looks almost
like a neon bulb with an opaque mercury-like metallic coating on the
inside of the glass bulb. There are 2 wires coming out of the base of
this little bulb, 1 connected to the black, and the other to the
white power wires that enter the base of the socket. Perhaps this is
the hard-wired starter? There are no markings on it at all. I
reattached the bulb, plugged in the fixture, and turn it on while
observing the little glass bulb. Nothing at all; no glow, no sparks,
no "tink" "tink" "tink". What do I replace it with?
Try an NE2 bulb? That's what used to be in the old starters.
ERRRRRRR! Wrong! I would suggest you find an old florescent starter
and take it apart, carefully break the glass off the silvered bulb
and you will find a heat activated bi-metal switch. A little searching
of The Interweb will help you learn how it works.
TDD
Follow up:
I cannibalized an unused FS-2 starter I found in my "junk box" and
wired in it's glow bulb in place of the defective glow bulb I clipped
out. To my surprise anddisappointment, when I replaced the CFL bulb,
plugged in the fixture and turned it on, the fixture and the glow
bulb both continuously flickered. I waited about 5-10 seconds to see
if it would stabilze; it didn't. I turned off the fixture, waited
about 10 seconds, tried again with the same result. I then added the
capacitor from the FS-2 in parallel with the glow bulb (as it was
wired within the FS-2). Same behavior.
Should I assume that the glow bulb from the FS-2 is mismatched to
this circuit (although the CLF is 18W and the FS-2 is rated for 14,
15, and 20W bulbs), or that something else is wrong in the circuit?
Should I buy a starter with a higher rating and try again with that?
This is a bit of a surprise to me. I have a fair amount of experience
with homebrewing and hacking of preheat fluorescent lamp fixtures, and
the behavior suggests to me that the starter is re-glowing too easily
from the voltage needed to fire the lamp.
This may be from the ballast skimping on current - that can make
starting crankier, and then the fixture can get fussier about starters.
You may be able to fix this by using a different FS-2 or FS-2 variant
starter, preferably one rated to start 22 watt lamps (along with lower
wattages).
Also, proper grounding may make a difference. Did you remove any
during your troubleshooting and repair attempt?
Winding a few turns of bare wire around the bulb, over the filaments,
has some chance of making the bulb easier to fire. This has to do with
capacitive coupling through the glass, so that a very small amount of
current does not have to go through the full length of the bulb. That
may make the gas in the bulb "break down" more easily.
There is even a remote chance that reversing the leads of the starter
will make things better. If ionization in the bulb occurs more easily
on one half-cycle of AC than the other due to polarity of the
electrode on the "hot side", then reversing the leads of the starter
may make a difference. I have seen starters having a polarity when
used with DC.
Also try reversing the plug, to reverse hot and neutral, if the plug
blades are the same width. (I forget already whether or not you said
the plug blades were equal width or not.) And check for hot-neutral
reverse at your outlet - that does affect a few cranky fluorescent
fixtures.
He could have two problems, a bad starter and a bad ballast. He has
eliminated the bulb since it worked in an identical light fixture.
Perhaps borrowing the ballast from a known good fixture? It may be
a lot work but I would do it out of curiosity.
TDD
Yeah, it would be interesting, but I don't want to investing that much effort.
Besides, just my luck I'd break off one of the wires where it enters the sealed
ballast unit and end up having to trash both fixtures!
I'm already coming close to my threshold for just giving up. The problem is
that these fixtures tend to run $60 - $120 and I'm only using it as a
supplemental local lighting source adjacent to my computer table. I'm thinking
of just getting a $10 USB LED lamp even though with all the clutter next to the
monitor, there's not a lot of room for something else on the desk top (CRT
monitor, so a clip-on lamp to the monitor frame is not an option).