CFL/ zapper problems
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From: David Nebenzahl on 11 Apr 2010 19:23 On 4/10/2010 10:23 PM Phil Allison spake thus: > "Catwatcher" > >> Had a similar problem with a dish network box about 2-3 years ago. The >> CFL was in a floor lamp line-of-sight about eight feet in front of the >> box. Pressing a key on the remote would yield unexpected results. After >> several days we correlated the problems with the light (which wasn't used >> all the time). I suspect the CFL emitted significant IR which confused >> the receiver in the box. > > ** Ordinary incandescent lamps emit lots of infra-red energy and have no > such effect - cos the IR is not modulated like the light coming from the > LED in a remote. > > So, what is different about CFLs ? > > Well, the internal inverter circuit operates at around 40kHz, so that must > be the culprit. > > But I see no way a CFL can generate MODULATED infra-red light - certainly > the tiny filaments will not do it and the phosphors have little IR output > and enough persistence to eliminate light modulation at such a high > frequency. > > However, the high voltage, high frequency drive to the fluoro tubes IS > radiated for several metres and can be picked up by sensitive electronic > devices. Just wave a scope probe near one and you will see what I mean. > > The photodiode amplifier circuit in an IR receiver is very sensitive, > operating down to the microvolt level, so it must be possible for a CFL > radiating the same operating frequency to interfere with them. Yes. Apparently, when you're on your meds it's hard to disagree with you. -- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com)
From: N_Cook on 12 Apr 2010 03:20 David Nebenzahl <nobody(a)but.us.chickens> wrote in message news:4bc258de$0$2367$822641b3(a)news.adtechcomputers.com... > On 4/10/2010 10:23 PM Phil Allison spake thus: > > > "Catwatcher" > > > >> Had a similar problem with a dish network box about 2-3 years ago. The > >> CFL was in a floor lamp line-of-sight about eight feet in front of the > >> box. Pressing a key on the remote would yield unexpected results. After > >> several days we correlated the problems with the light (which wasn't used > >> all the time). I suspect the CFL emitted significant IR which confused > >> the receiver in the box. > > > > ** Ordinary incandescent lamps emit lots of infra-red energy and have no > > such effect - cos the IR is not modulated like the light coming from the > > LED in a remote. > > > > So, what is different about CFLs ? > > > > Well, the internal inverter circuit operates at around 40kHz, so that must > > be the culprit. > > > > But I see no way a CFL can generate MODULATED infra-red light - certainly > > the tiny filaments will not do it and the phosphors have little IR output > > and enough persistence to eliminate light modulation at such a high > > frequency. > > > > However, the high voltage, high frequency drive to the fluoro tubes IS > > radiated for several metres and can be picked up by sensitive electronic > > devices. Just wave a scope probe near one and you will see what I mean. > > > > The photodiode amplifier circuit in an IR receiver is very sensitive, > > operating down to the microvolt level, so it must be possible for a CFL > > radiating the same operating frequency to interfere with them. > > Yes. > > Apparently, when you're on your meds it's hard to disagree with you. > > > -- > The fashion in killing has an insouciant, flirty style this spring, > with the flaunting of well-defined muscle, wrapped in flags. > > - Comment from an article on Antiwar.com (http://antiwar.com) Next time I'm faced with some kit with missing IR R/C and the "universal" ones don't work I will have to try a CFL near it and see what happens. Monitoring the "datastream " with a scope if there is any effect. It would seem no one in the thread has tried shielding CFL with IR blocking plastic and trying , then grounded metal can around the CFL, to establish IR interference, airborne RFI or mains wiring RFI -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://diverse.4mg.com/index.htm
From: Phil Allison on 12 Apr 2010 04:14 "Nutcase Kook" > It would seem no one in the thread has tried shielding CFL with IR > blocking > plastic and trying , then grounded metal can around the CFL, to establish > IR > interference, airborne RFI or mains wiring RFI ** Cos the effect is so rare it is like cases of Man Bites Dog. One only reads of alleged examples and hears anecdotes on the topic. ..... Phil
From: William Sommerwerck on 12 Apr 2010 06:36 I saw this effect once with a conventional fluorescent lamp and a VCR. My bedroom lamp is a CFL, and it has no effect whatever on the TV or DVD player. This is random event.
From: N_Cook on 12 Apr 2010 07:26
William Sommerwerck <grizzledgeezer(a)comcast.net> wrote in message news:hput2h$89o$1(a)news.eternal-september.org... > I saw this effect once with a conventional fluorescent lamp and a VCR. > > My bedroom lamp is a CFL, and it has no effect whatever on the TV or DVD > player. > > This is random event. > > I've only seen it once with CFL and late 1970s Akai cassette player with IR remote , so probably very simple coding in those early days |