Why is one lightbulb in a string illuminated?
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3
$begingroup$
I noticed that in various strings of lights only one was illuminated. It seems implausible that all but one out of several hundred blew. What caused this and why did this particular light turn on?
parallel lighting
asked 4 hours ago
dothyphendotdothyphendot
1161
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dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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add a comment |
3
$begingroup$
I noticed that in various strings of lights only one was illuminated. It seems implausible that all but one out of several hundred blew. What caused this and why did this particular light turn on?
parallel lighting
asked 4 hours ago
dothyphendotdothyphendot
1161
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
1
$begingroup$
I think there is too less information to answer this question without speculation, and there is probably neither no way to validate an answer in order to accept it.
$endgroup$
– Huisman
3 hours ago
$begingroup$
Never seen serial streetlights on cables from street-corners before. But if there enough mutual coupling to power 1 bulb out of say 30 in series. The bulb with the fastest warm-up time draws all the induced voltage ( e.g. 240/30) due to 10:1 PTC effects
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Looks a lovely park not far from the Welsh coast
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
How about this: The lamps are on a photocell-switched circuit, but one lamp is lit constantly to indicate that the circuit is powered. It's not dark enough to trigger to photocell switch.
$endgroup$
– Hot Licks
4 mins ago
add a comment |
3
3
3
2
$begingroup$
I noticed that in various strings of lights only one was illuminated. It seems implausible that all but one out of several hundred blew. What caused this and why did this particular light turn on?
parallel lighting
asked 4 hours ago
dothyphendotdothyphendot
1161
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I noticed that in various strings of lights only one was illuminated. It seems implausible that all but one out of several hundred blew. What caused this and why did this particular light turn on?
parallel lighting
parallel lighting
asked 4 hours ago
dothyphendotdothyphendot
1161
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 4 hours ago
dothyphendotdothyphendot
1161
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 4 hours ago
dothyphendotdothyphendot
1161
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 4 hours ago
dothyphendotdothyphendot
1161
asked 4 hours ago
dothyphendotdothyphendot
1161
1161
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
dothyphendot is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
1
$begingroup$
I think there is too less information to answer this question without speculation, and there is probably neither no way to validate an answer in order to accept it.
$endgroup$
– Huisman
3 hours ago
$begingroup$
Never seen serial streetlights on cables from street-corners before. But if there enough mutual coupling to power 1 bulb out of say 30 in series. The bulb with the fastest warm-up time draws all the induced voltage ( e.g. 240/30) due to 10:1 PTC effects
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Looks a lovely park not far from the Welsh coast
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
How about this: The lamps are on a photocell-switched circuit, but one lamp is lit constantly to indicate that the circuit is powered. It's not dark enough to trigger to photocell switch.
$endgroup$
– Hot Licks
4 mins ago
add a comment |
1
$begingroup$
I think there is too less information to answer this question without speculation, and there is probably neither no way to validate an answer in order to accept it.
$endgroup$
– Huisman
3 hours ago
$begingroup$
Never seen serial streetlights on cables from street-corners before. But if there enough mutual coupling to power 1 bulb out of say 30 in series. The bulb with the fastest warm-up time draws all the induced voltage ( e.g. 240/30) due to 10:1 PTC effects
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Looks a lovely park not far from the Welsh coast
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
How about this: The lamps are on a photocell-switched circuit, but one lamp is lit constantly to indicate that the circuit is powered. It's not dark enough to trigger to photocell switch.
$endgroup$
– Hot Licks
4 mins ago
1
1
$begingroup$
I think there is too less information to answer this question without speculation, and there is probably neither no way to validate an answer in order to accept it.
$endgroup$
– Huisman
3 hours ago
$begingroup$
I think there is too less information to answer this question without speculation, and there is probably neither no way to validate an answer in order to accept it.
$endgroup$
– Huisman
3 hours ago
$begingroup$
Never seen serial streetlights on cables from street-corners before. But if there enough mutual coupling to power 1 bulb out of say 30 in series. The bulb with the fastest warm-up time draws all the induced voltage ( e.g. 240/30) due to 10:1 PTC effects
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Never seen serial streetlights on cables from street-corners before. But if there enough mutual coupling to power 1 bulb out of say 30 in series. The bulb with the fastest warm-up time draws all the induced voltage ( e.g. 240/30) due to 10:1 PTC effects
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Looks a lovely park not far from the Welsh coast
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Looks a lovely park not far from the Welsh coast
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
How about this: The lamps are on a photocell-switched circuit, but one lamp is lit constantly to indicate that the circuit is powered. It's not dark enough to trigger to photocell switch.
$endgroup$
– Hot Licks
4 mins ago
$begingroup$
How about this: The lamps are on a photocell-switched circuit, but one lamp is lit constantly to indicate that the circuit is powered. It's not dark enough to trigger to photocell switch.
$endgroup$
– Hot Licks
4 mins ago
add a comment |
2 Answers
2
active
oldest
votes
2
$begingroup$
Figure 1. The intriguing light bulb has caught the attention of Smokey the Bear too.
There can only be a few possibilities:
- The lamps are spread across several phases or split phases, the other phases are off and all but this lamp has blown. This is very unlikely.
- Some joker has installed a battery powered lamp. This too seems unlikely.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.
- The impossible has happened and all have blown but one. This could happen with an overvoltage - by lightning, for example. Some combination of poor contact, tough filament, arcing in another lamp (which would limit the voltage), etc., may be enough to let it survive.
Another possibility is that the power is on and that each bulb has its own light sensor (like some streetlights) and this one is the first to switch on. Again, unlikely.
answered 4 hours ago
TransistorTransistor
89.4k786192
$endgroup$
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
add a comment |
0
$begingroup$
I'd go with the implausible explanation. All the bulbs are blown except the one.
Most festoon lights use a screw-in socket so all the lights are in parallel:
I'd suggest that the string was perhaps hit by a truck (or a surge) and a bunch of the lights broke.
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
2
$begingroup$
Figure 1. The intriguing light bulb has caught the attention of Smokey the Bear too.
There can only be a few possibilities:
- The lamps are spread across several phases or split phases, the other phases are off and all but this lamp has blown. This is very unlikely.
- Some joker has installed a battery powered lamp. This too seems unlikely.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.
- The impossible has happened and all have blown but one. This could happen with an overvoltage - by lightning, for example. Some combination of poor contact, tough filament, arcing in another lamp (which would limit the voltage), etc., may be enough to let it survive.
Another possibility is that the power is on and that each bulb has its own light sensor (like some streetlights) and this one is the first to switch on. Again, unlikely.
answered 4 hours ago
TransistorTransistor
89.4k786192
$endgroup$
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
add a comment |
2
$begingroup$
Figure 1. The intriguing light bulb has caught the attention of Smokey the Bear too.
There can only be a few possibilities:
- The lamps are spread across several phases or split phases, the other phases are off and all but this lamp has blown. This is very unlikely.
- Some joker has installed a battery powered lamp. This too seems unlikely.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.
- The impossible has happened and all have blown but one. This could happen with an overvoltage - by lightning, for example. Some combination of poor contact, tough filament, arcing in another lamp (which would limit the voltage), etc., may be enough to let it survive.
Another possibility is that the power is on and that each bulb has its own light sensor (like some streetlights) and this one is the first to switch on. Again, unlikely.
answered 4 hours ago
TransistorTransistor
89.4k786192
$endgroup$
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
add a comment |
2
2
2
$begingroup$
Figure 1. The intriguing light bulb has caught the attention of Smokey the Bear too.
There can only be a few possibilities:
- The lamps are spread across several phases or split phases, the other phases are off and all but this lamp has blown. This is very unlikely.
- Some joker has installed a battery powered lamp. This too seems unlikely.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.
- The impossible has happened and all have blown but one. This could happen with an overvoltage - by lightning, for example. Some combination of poor contact, tough filament, arcing in another lamp (which would limit the voltage), etc., may be enough to let it survive.
Another possibility is that the power is on and that each bulb has its own light sensor (like some streetlights) and this one is the first to switch on. Again, unlikely.
answered 4 hours ago
TransistorTransistor
89.4k786192
$endgroup$
Figure 1. The intriguing light bulb has caught the attention of Smokey the Bear too.
There can only be a few possibilities:
- The lamps are spread across several phases or split phases, the other phases are off and all but this lamp has blown. This is very unlikely.
- Some joker has installed a battery powered lamp. This too seems unlikely.
"When you have eliminated the impossible, whatever remains, however improbable, must be the truth." Sherlock Holmes.
- The impossible has happened and all have blown but one. This could happen with an overvoltage - by lightning, for example. Some combination of poor contact, tough filament, arcing in another lamp (which would limit the voltage), etc., may be enough to let it survive.
Another possibility is that the power is on and that each bulb has its own light sensor (like some streetlights) and this one is the first to switch on. Again, unlikely.
answered 4 hours ago
TransistorTransistor
89.4k786192
edited 3 hours ago
answered 4 hours ago
TransistorTransistor
89.4k786192
answered 4 hours ago
TransistorTransistor
89.4k786192
answered 4 hours ago
TransistorTransistor
89.4k786192
89.4k786192
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
add a comment |
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
I'd go with the battery powered hypothesis, there are available lamps that include a battery back-up
$endgroup$
– Jasen
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
Are these lamps connected in series or parallel? Or several series strings in parallel?
$endgroup$
– Toor
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
looks like parallel festoon fittings to me
$endgroup$
– Jasen
4 hours ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
$begingroup$
Then the o/v has my vote. Someone may have fitted a single 275V (very likely 260V) globe as a spare. We had these in Western Australia for a long time and they lasted forever back when we were 250V and the rest of the country 240V. (almost always higher in both cases).
$endgroup$
– mckenzm
33 mins ago
add a comment |
0
$begingroup$
I'd go with the implausible explanation. All the bulbs are blown except the one.
Most festoon lights use a screw-in socket so all the lights are in parallel:
I'd suggest that the string was perhaps hit by a truck (or a surge) and a bunch of the lights broke.
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
$endgroup$
add a comment |
0
$begingroup$
I'd go with the implausible explanation. All the bulbs are blown except the one.
Most festoon lights use a screw-in socket so all the lights are in parallel:
I'd suggest that the string was perhaps hit by a truck (or a surge) and a bunch of the lights broke.
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
$endgroup$
add a comment |
0
0
0
$begingroup$
I'd go with the implausible explanation. All the bulbs are blown except the one.
Most festoon lights use a screw-in socket so all the lights are in parallel:
I'd suggest that the string was perhaps hit by a truck (or a surge) and a bunch of the lights broke.
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
$endgroup$
I'd go with the implausible explanation. All the bulbs are blown except the one.
Most festoon lights use a screw-in socket so all the lights are in parallel:
I'd suggest that the string was perhaps hit by a truck (or a surge) and a bunch of the lights broke.
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
answered 3 hours ago
Jack CreaseyJack Creasey
15.4k2823
15.4k2823
add a comment |
add a comment |
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1
$begingroup$
I think there is too less information to answer this question without speculation, and there is probably neither no way to validate an answer in order to accept it.
$endgroup$
– Huisman
3 hours ago
$begingroup$
Never seen serial streetlights on cables from street-corners before. But if there enough mutual coupling to power 1 bulb out of say 30 in series. The bulb with the fastest warm-up time draws all the induced voltage ( e.g. 240/30) due to 10:1 PTC effects
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
Looks a lovely park not far from the Welsh coast
$endgroup$
– Sunnyskyguy EE75
3 hours ago
$begingroup$
How about this: The lamps are on a photocell-switched circuit, but one lamp is lit constantly to indicate that the circuit is powered. It's not dark enough to trigger to photocell switch.
$endgroup$
– Hot Licks
4 mins ago