rickj@syacus.acus.oz (Rick Jones) (01/07/91)
Hi, Last week my wife called me into our son's room complaining that she couldn't turn off his flourescent light. After my initial reaction of wondering just how many cylinders she was really firing on, I went and investigated. The light, even when turned off at the switch, continued to flicker to full brightness and then die again, repeating this every twenty seconds or so. I pulled the switch out and tested it. All OK! What causes this type of aparent aberration? Another side effect was that, if I touched the tube, I received the same sort of response that you'd expect from a plasma display tube, with the light radiating to my fingertips. Can anyone shed any light on this (pardon the pun)? Regards, Rick. -- ============================================================================ Rick Jones (Software Engineer) | Telephone: (+61 2) 390-1375 Australian Centre for Unisys Software (ACUS) | Facsimile: (+61 2) 390-1391 rickj@syacus.acus.oz.au | FidoNet: 3:713/616.0
mcovingt@athena.cs.uga.edu (Michael A. Covington) (01/08/91)
2 questions: (1) Are your lights controlled indirectly somehow, e.g., through relays, or through a switch that bypasses something just long enough to get the fluorescent light started (like a push-to-start button)? (2) Could be a grounding problem, especially since you're in a country with 240V mains. 240V on one side and a high-resistance ground on the other _could_ light a fluorescent bulb. They're famous for being able to glow -- weakly -- on very low current if the voltage is high enough.
mb@sparrms.ists.ca (Mike Bell) (01/09/91)
In <1991Jan7.060704.6882@syacus.acus.oz> rickj@syacus.acus.oz (Rick Jones) writes: >The light, even when turned off at the switch, continued to flicker to full >brightness and then die again, repeating this every twenty seconds or so. Don't live near a high power RF source by any chance? Radar? TV transmitter? Low flying AWACS? Probably just being scanned by the starship Enterprise...
pierson@ggone.enet.dec.com (Dave Pierson) (01/09/91)
In article <1991Jan8.044340.11045@athena.cs.uga.edu>, mcovingt@athena.cs.uga.edu (Michael A. Covington) writes, in part, concerning a fluorescent light which won't go "off" >2 questions: >(2) Could be a grounding problem, especially since you're in a country >with 240V mains. 240V on one side and a high-resistance ground on the >other _could_ light a fluorescent bulb. They're famous for being able >to glow -- weakly -- on very low current if the voltage is high enough. In a similar vein, if the switch were installed in the low/neutral side of the line, this would leave the lamp energized at 220/240, even with the switch off. This could lead to the dim flickering effect, due to physical leakage to a (?)grounded fixture, or capcitive coupling to same. The description of the glow following fingers brushed along the tube supports this. I have no idea as to the "electric code" applicable, in general, at least in tne US, the switch must/should be in the "hot" side of any load. (I assume this is a 240_to_neutral, which is the usual arrangement in "240 v" juridictions.) thanks dave pierson |the facts, as accurately as i can manage, Digital Equipment Corporation |the opinions, my own. 600 Nickerson Rd Marlboro, Mass 01752 pierson@cimnet.enet.dec.com "He has read everything, and, to his credit, written nothing." A J Raffles
davet@tsdiag.ccur.com (Dave Tiller N2KAU) (01/09/91)
In article <1991Jan7.060704.6882@syacus.acus.oz> rickj@syacus.acus.oz (Rick Jones) writes:
-
-Hi,
-
-Last week my wife called me into our son's room complaining that she
-couldn't turn off his flourescent light. After my initial reaction of
-wondering just how many cylinders she was really firing on, I went and
-investigated.
-
-The light, even when turned off at the switch, continued to flicker to full
-brightness and then die again, repeating this every twenty seconds or so.
-
-I pulled the switch out and tested it. All OK! What causes this type of
-aparent aberration? Another side effect was that, if I touched the tube, I
-received the same sort of response that you'd expect from a plasma display
-tube, with the light radiating to my fingertips.
-
-Can anyone shed any light on this (pardon the pun)?
Do you have any strong radio transmitters around your area? Airport radar,
military stuff, amateur radio? It sounds like a high ambient EM field is
ionizing the gas in the tube. (My 5W handheld on 144MHz will light a three
foot tube.)
--
David E. Tiller davet@tsdiag.ccur.com | Concurrent Computer Corp.
FAX: 201-870-5952 Ph: (201) 870-4119 (w) | 2 Crescent Place, M/S 117
UUCP: ucbvax!rutgers!petsd!tsdiag!davet | Oceanport NJ, 07757
ICBM: 40 16' 52" N 73 59' 00" W | N2KAU @ NN2Zcgordon@vpnet.chi.il.us (gordon hlavenka) (01/09/91)
rickj@syacus.acus.oz (Rick Jones) writes: >The light, even when turned off at the switch, continued to flicker to full >brightness and then die again, repeating this every twenty seconds or so. > >I pulled the switch out and tested it. All OK! What causes this type of >aparent aberration? Another side effect was that, if I touched the tube, I >received the same sort of response that you'd expect from a plasma display >tube, with the light radiating to my fingertips. > >Can anyone shed any light on this (pardon the pun)? These are _exactly_ he symptoms I saw when I had a fixture wired with the switch on the neutral side of the mains. It wouldn't do it all the time; it seemed to depend on the weather. Moved the switch to the hot lead and things got normal. It had been miswired for a couple of years with no symptoms. >Rick Jones (Software Engineer) It's a hardware problem. -- ----------------------------------------------------- Gordon S. Hlavenka cgordon@vpnet.chi.il.us Disclaimer: Yeah, I said it. So what? -- ----------------------------------------------------- Gordon S. Hlavenka cgordon@vpnet.chi.il.us Disclaimer: Yeah, I said it. So what?
rbrink@hubcap.clemson.edu (Rick Brink) (01/10/91)
I've had similar experiences with a Leud flourescent desk lamp I keep at bed side. I used to sleep on an Electrically heated sheet (I quit when ELM research started appearing). The similarity to the flouro with it's own mind....When I touched the bulb in the lamp, it glowed at nearly full brightness. It also did the turn it's self on later trick. This lamp is the starterless heater type, but many times, touching the bulb, while lying on the sheet (on) would start the bulb, and only unpluging the lamp would turn it off. As I said, I ditched the electric sheet... I disassembled the lamp and found no grounded connections, but when I re-assembled it, the problem disappeared. I suspect a grounded connection, or the combination of bad ground and an incorrectly wired outlet (hot/neutral reversed) was the problem. As the rework was done just after I moved to a new place. I'd check the wiring on the fixture you have though. If you are breaking the neutral, not the hot, leakage in the transformer might let it arc to the safty ground and pop back on. But I'd say you have a bad transformer in the light as well now.
robf@mcs213k.cs.umr.edu (Rob Fugina) (01/10/91)
Just in case anybody finds this interesting...I just cought a "Mr. Wizard" TV show where Mr. Wizard put a flourescent bulb in a microwave oven (with a few cups of water, so the oven wouldn't arc) and THAT lit the bulb... Rob robf@cs.umr.edu
bobm@anasaz.UUCP (Bob Maccione) (01/10/91)
In article <12543@hubcap.clemson.edu> rbrink@hubcap.clemson.edu (Rick Brink) writes: >I've had similar experiences with a Leud flourescent desk lamp I keep at >bed side. I used to sleep on an Electrically heated sheet (I quit when >ELM research started appearing). The similarity to the flouro with it's >own mind....When I touched the bulb in the lamp, it glowed at nearly full >brightness. It also did the turn it's self on later trick. This lamp is >the starterless heater type, but many times, touching the bulb, while lying >on the sheet (on) would start the bulb, and only unpluging the lamp would >turn it off. I had the same problem when I used to sleep on a water bed. My alarm clock was one of those with a touch bar to snooze ( works off body capacitance i figure ) and if the heater was on I couldn't get into snooze mode unless I either got out of the bed or turned the heater off ( via the thermostat ). OBQuestion: Could someone send me some pointers to articles on ELM? thanks bob maccione