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Strange problem with low energy light bulb
I am not sure if this is an appropriate group for this question. If
not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote in message
ups.com... I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair It may not be a switch problem but more seriously an animal , usually squirrel or mouse or rat has chewed the insulation along the wires going to the switch, now with charred insulation, so passing a bit of current - so get the wiring leakage/visually checked. Especially if you've had any unexplained fuses blowing or history of animal noises in loft or floor spaces. -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
Strange problem with low energy light bulb
On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote:
I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Bruce |
Strange problem with low energy light bulb
On 25 Jun, 15:21, BH wrote:
On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
On 25 Jun, 15:20, "N Cook" wrote:
Seán O'Leathlóbhair wrote in message ups.com... I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair It may not be a switch problem but more seriously an animal , usually squirrel or mouse or rat has chewed the insulation along the wires going to the switch, now with charred insulation, so passing a bit of current - so get the wiring leakage/visually checked. Especially if you've had any unexplained fuses blowing or history of animal noises in loft or floor spaces. Thanks for the advice. We had some fuse problems many years ago but not on the lighting circuits. The problem was traced (by a proper electrician) to the ancient (bakelite) fuse box. It was replaced with a modern fuse box. The wiring was tested (but not completely inspected) at the time. Since then, we have not had any fuse problems. That was about 10 years ago. I am not aware of any animal problems in the loft but, of course, that does not mean that there have not been any. Access to the loft is difficult since it is very small but not quite impossible. I will squeeze myself in and have a look. -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote:
On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. Ken |
Strange problem with low energy light bulb
On 25 Jun, 15:39, Ken Weitzel wrote:
Seán O'Leathlóbhair wrote: On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. A good question but no. It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote:
On 25 Jun, 15:39, Ken Weitzel wrote: Seán O'Leathlóbhair wrote: On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. A good question but no. It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). Sounds like leakage to me, there may be a measurable voltage floating on the neutral. I has a similar problem with fluorescent emergency lights last year. If you are in the UK it might be an earthing fault. Ron(UK) |
Strange problem with low energy light bulb
On 25 Jun, 15:56, "Ron(UK)" wrote:
Seán O'Leathlóbhair wrote: On 25 Jun, 15:39, Ken Weitzel wrote: Seán O'Leathlóbhair wrote: On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. A good question but no. It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). Sounds like leakage to me, there may be a measurable voltage floating on the neutral. I has a similar problem with fluorescent emergency lights last year. If you are in the UK it might be an earthing fault. I am in the UK. How does an earthing fault affect the lighting circuit? I thought it was just two wire. The earthing for the house in general was checked a couple of years ago when we changed the boiler. The gas engineer said that a change was required but I forget exactly what that was. The RCCB in the new fuse box is not tripping but does it apply to the lighting circuits? -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
Hi, this isn;t that uncommon a problem with low energy bulbs. Its
probable that there is a voltage induced into the 'dead' circuit by cables running in close proximity to one another. Typically this occurs on long cable runs for hall/landing circuits. The way I'd bottom it is to use a DVM across the lamp socket & see what voltage is present. You shouldn't be able to draw any current (to speak of) from a capacitive or inductive coupling. What happens is that theres enough voltage for the tube to strike but no capacity to draw current, so it goes out until the voltage builds up again. You can buy suppression capacitors to overcome this (Note they are special devices - don't try to bodge it!) but sometimes just swapping with another LE bulb will do the trick. If the problem isn't as described, you'd better get someone in to check the wiring for contacts or earth problems. Dale. On Mon, 25 Jun 2007 08:04:04 -0700, Seán O'Leathlóbhair wrote: On 25 Jun, 15:56, "Ron(UK)" wrote: Seán O'Leathlóbhair wrote: On 25 Jun, 15:39, Ken Weitzel wrote: Seán O'Leathlóbhair wrote: On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. A good question but no. It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). Sounds like leakage to me, there may be a measurable voltage floating on the neutral. I has a similar problem with fluorescent emergency lights last year. If you are in the UK it might be an earthing fault. I am in the UK. How does an earthing fault affect the lighting circuit? I thought it was just two wire. The earthing for the house in general was checked a couple of years ago when we changed the boiler. The gas engineer said that a change was required but I forget exactly what that was. The RCCB in the new fuse box is not tripping but does it apply to the lighting circuits? |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote:
I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair On a cold wet miserable winter day in the early 70's. I was troubleshooting a newish car, that wouldn't start, that had just been serviced by a car dealership. a few days before. To cut a long story short, they lubricated the Point Breaker mechanism with a clear Grease that they probably used for years with no problems ! With 2 to 6 Amps flowing, the contact mechanism probably cooked off any wet or conductive grease. With the newer Hybrid Transistor switched points the DAMP grease appeared as a Dead Short to the few milliamps required to actuate the Transistor. I would suspect the switches (All three) are lubricated with a grease that is conductive enough read (dirty enough)to cause the problems indicated ! The quick and dirty, to clear the excess grease is to replace the lamp in question with a 60 - 100 watt bulb and switch On and Off a few times. in the Off position any conductive grease will be burned away. Any fire Hazard, Not likely, after all these switches were manufactured and sold for years lubricated just like this, besides we are talking about a drop or two grease total ! If you are worried, replace the switches. If this doesn't clear the problem than you may have exessive capacitative coupling between the various conductors due to the three-way switching, under a very light load ! Yukio YANO |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. In order to do that it must be getting power from somewhere. You must have a fault in the switch or related wiring. Graham |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. That would appear to be the case. Graham |
Strange problem with low energy light bulb
Scalp wrote: Hi, this isn;t that uncommon a problem with low energy bulbs. Its probable that there is a voltage induced into the 'dead' circuit by cables running in close proximity to one another. Typically this occurs on long cable runs for hall/landing circuits. How is this voltage induced ? Are you suggesting electromagnetic coupling ? That sounds astonishingly unlikely. Graham |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote:
It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). Sounds like leakage to me, there may be a measurable voltage floating on the neutral. I has a similar problem with fluorescent emergency lights last year. If you are in the UK it might be an earthing fault. I am in the UK. How does an earthing fault affect the lighting circuit? I thought it was just two wire. The earthing for the house in general was checked a couple of years ago when we changed the boiler. The gas engineer said that a change was required but I forget exactly what that was. The RCCB in the new fuse box is not tripping but does it apply to the lighting circuits? If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. It could be a faulty switch leaking across the contacts. You don't live beneath an electricity pylon do you? It might also be the rays from guvmint mind control experiments entering your house. ;) Ron(UK) |
Strange problem with low energy light bulb
On Mon, 25 Jun 2007 07:45:29 -0700, Seán O'Leathlóbhair
wrote: On 25 Jun, 15:39, Ken Weitzel wrote: Seán O'Leathlóbhair wrote: On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. A good question but no. It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). Your switches are wired wrong (they are switching the neutral (or cold) side of the line, not the hot side. As well, you seem to have a leakage problem in the circuit as well. This leakage could be a switch or some other device or part. First step is to make 100% sure the switches are in the hot side of the circuit. That will likely solve your problem immediately. I'd guess there is a chance much of your house is not wired correctly from your description... Not sure what building codes/wriing codes you have in the UK, but in the US this circuit would not have passed a building inspector. |
Strange problem with low energy light bulb
"Ron(UK)" wrote: If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. Ron, when the switch is off, there is no circuit. The neutral potential literally doesn't matter. Graham |
Strange problem with low energy light bulb
PeterD wrote: Your switches are wired wrong (they are switching the neutral (or cold) side of the line, not the hot side. Makes no difference. When the switch is off, the circuit is broken. Graham |
Strange problem with low energy light bulb
Eeyore wrote:
"Ron(UK)" wrote: If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. Ron, when the switch is off, there is no circuit. The neutral potential literally doesn't matter. Graham Capacitive leakage from the HOT wire to the switch wire? That could trickle charge and cause an occasional flicker. Random spikes would leak through much easier, and cause random flicker. Try as cure a small capacitor (100NF)across the lamp terminals, just as long as the cap is much bigger than the parasite one. |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote:
I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) So many replies that it is hard to know which one to reply to so I will reply here. A curious feature that I forgot to mention is the regularlity of the flashes: every 2 seconds with no variation that I can detect with a stop watch. This is why I thought of a capacitor charging up until it reaches a critical voltage. But I was thinking of DC. AC is not going to charge up a capacitor over 2 seconds. What is inside these bulbs? A rectifier? A capacitor? I will do some checking at the weekend. Climb into the loft space for a look. Get the multimeter out. Trying other low energy bulbs. Try the higher rated bulb. Etc. -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
Sjouke Burry wrote: Capacitive leakage from the HOT wire to the switch wire? So why doesn't this happen all the time ? Answer, the capacitance is very low, as is the frequency. Graham |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote: What is inside these bulbs? A rectifier? A capacitor? Lots of stuff. Graham |
Strange problem with low energy light bulb
Eeyore wrote:
Sjouke Burry wrote: Capacitive leakage from the HOT wire to the switch wire? So why doesn't this happen all the time ? Answer, the capacitance is very low, as is the frequency. Graham A leak cap has very high impedance, and via the input rectifier can charge the input cap(slowly). Then when a threshold is passed, the circuit produces a flash. And it only happens, if the input capacity of the rectifier circuit is low compared to the leak cap. |
Strange problem with low energy light bulb
Chris Jones wrote:
Seán O'Leathlóbhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair This has come up before in aus.electronics though I don't recall if there was a definite cure for it. Thanks. If there is no danger, I don't need a cure. The flash is not irritating. The CO detector nearby flashes more brightly. I am just worried that it is telling me that something nasty is wrong with my wiring. -- Seán Ó Leathlóbhair |
Strange problem with low energy light bulb
Hi!
When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. Do you have one of those switches that glows when you turn it off? I have one attached to set a of conventional fluorescent fixtures (one four tube and one two tube). When the switch is "off" it still passes a tiny amount of current and this makes for a faint flashing in the two tube fixture. As far as I can tell this is perfectly safe...it has never caused any problems for the lamp or myself. I do, however, have to turn the power off when changing the lamps in the two tube fixture. Otherwise there is the possibility of getting a small shock. William |
Strange problem with low energy light bulb
On Mon, 25 Jun 2007 07:03:01 -0700, Seán O'Leathlóbhair
put finger to keyboard and composed: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) There was a similar thread at aus.electronics earlier this year. CFL "pulses" when off! http://groups.google.com/group/aus.e...04b7d5a?hl=en& I don't know if anything was resolved, but the distributor of a certain CFL brand wrote: "We have found after much research that certain homes that are wired in a way where they are switching the neutral that this may occur with these lamps." One contributor theorised that the switch wire may act as a capacitance. This would allow the main filter capacitor to gradually charge up via the bridge rectifier to the point where the circuit may "kick", after which the flash would discharge the capacitor and the cycle would start again. This person experimented with various series caps and resistors: http://groups.google.com/group/aus.e...5398c8c?hl=en& Here is an interesting site that shows what is inside these lamps: http://www.pavouk.org/hw/lamp/en_index.html - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
Strange problem with low energy light bulb
Hi!
I have a few questions: What is going on? See my other reply. Do you have a light switch that glows when you turn it off? This will place a small amount of current flow across the lamp, which may make it flicker. Will it wear out the bulb very fast? It may result in a slight amount of wear on the bulb, but I doubt the change in lifetime would ever be noticed. What is inside these bulbs? A rectifier? A capacitor? In many cases, these bulbs contain a small switchmode power supply. Such a power supply will have a transistor, some type of controller, a small transformer and some support components (of which a capacitor would probably be included). Others use a much simpler transformer design. William |
Strange problem with low energy light bulb
Sjouke Burry wrote: Eeyore wrote: Sjouke Burry wrote: Capacitive leakage from the HOT wire to the switch wire? So why doesn't this happen all the time ? Answer, the capacitance is very low, as is the frequency. A leak cap has very high impedance, and via the input rectifier can charge the input cap(slowly). Then when a threshold is passed, the circuit produces a flash. And it only happens, if the input capacity of the rectifier circuit is low compared to the leak cap. It flashes every 2 seconds or so. Clearly a very low leakage current won't do that. Graham |
Strange problem with low energy light bulb
On Mon, 25 Jun 2007 22:28:59 GMT, Eeyore
put finger to keyboard and composed: Sjouke Burry wrote: Eeyore wrote: Sjouke Burry wrote: Capacitive leakage from the HOT wire to the switch wire? So why doesn't this happen all the time ? Answer, the capacitance is very low, as is the frequency. A leak cap has very high impedance, and via the input rectifier can charge the input cap(slowly). Then when a threshold is passed, the circuit produces a flash. And it only happens, if the input capacity of the rectifier circuit is low compared to the leak cap. It flashes every 2 seconds or so. Clearly a very low leakage current won't do that. Graham This fellow experimented with a ~1mA leakage current at 240VAC: http://groups.google.com/group/aus.e...5398c8c?hl=en& "Changed to 270 kohms and now have a 13W CFL flashing at exactly 1 Hz". - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
Strange problem with low energy light bulb
Seán O'Leathlóbhair wrote:
I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Seán Ó Leathlóbhair This has come up before in aus.electronics though I don't recall if there was a definite cure for it. Chris |
Strange problem with low energy light bulb
Eeyore wrote:
"Ron(UK)" wrote: If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. Ron, when the switch is off, there is no circuit. The neutral potential literally doesn't matter. Graham It`s a two way switch, there`s plenty of potential for leakage paths. You can easily get 100v on the neutral if it`s floating above earth potential. Ron(UK) |
Strange problem with low energy light bulb
"Ron(UK)" wrote in message ... Seán O'Leathlóbhair wrote: It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). Sounds like leakage to me, there may be a measurable voltage floating on the neutral. I has a similar problem with fluorescent emergency lights last year. If you are in the UK it might be an earthing fault. I am in the UK. How does an earthing fault affect the lighting circuit? I thought it was just two wire. The earthing for the house in general was checked a couple of years ago when we changed the boiler. The gas engineer said that a change was required but I forget exactly what that was. The RCCB in the new fuse box is not tripping but does it apply to the lighting circuits? If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. It could be a faulty switch leaking across the contacts. You don't live beneath an electricity pylon do you? It might also be the rays from guvmint mind control experiments entering your house. ;) Ron(UK) Ron - just a quick aside. It was you that I was talking to a few weeks back about the old ILP audio modules, wasn't it ? Well, thought you might be interested to know that the next issue of Elektor ( that'll be the September one as it is currently the July / August Summer Circuits double issue ) is doing a review and lab tests of a number of available pre-built audio modules. Arfa |
Strange problem with low energy light bulb
"Ron(UK)" wrote: Eeyore wrote: "Ron(UK)" wrote: If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. Ron, when the switch is off, there is no circuit. The neutral potential literally doesn't matter. It`s a two way switch, there`s plenty of potential for leakage paths. You can easily get 100v on the neutral if it`s floating above earth potential. The OP said they weren't 2 way circuits though. Graham |
Strange problem with low energy light bulb
Franc Zabkar wrote: Eeyore put finger to keyboard and composed: Sjouke Burry wrote: Eeyore wrote: Sjouke Burry wrote: Capacitive leakage from the HOT wire to the switch wire? So why doesn't this happen all the time ? Answer, the capacitance is very low, as is the frequency. A leak cap has very high impedance, and via the input rectifier can charge the input cap(slowly). Then when a threshold is passed, the circuit produces a flash. And it only happens, if the input capacity of the rectifier circuit is low compared to the leak cap. It flashes every 2 seconds or so. Clearly a very low leakage current won't do that. This fellow experimented with a ~1mA leakage current at 240VAC: http://groups.google.com/group/aus.e...5398c8c?hl=en& "Changed to 270 kohms and now have a 13W CFL flashing at exactly 1 Hz". I make that ~ 11nF ! You won't get that easily. Graham |
Strange problem with low energy light bulb
=?iso-8859-1?B?U2XhbiBPJ0xlYXRobPNiaGFpcg==?= writes:
On 25 Jun, 15:39, Ken Weitzel wrote: Se=E1n O'Leathl=F3bhair wrote: On 25 Jun, 15:21, BH wrote: On Jun 25, 10:03 am, Se=E1n O'Leathl=F3bhair wrot= e: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) -- Se=E1n =D3 Leathl=F3bhair Try the buld in another location. Give us moe information on the bulb. Thanks. Normally, I would immediately try to isolate the cause by moving things around but, in this case, I dismissed the bulb as the problem since I thought that if the switch was passing nothing when off (as it should) then there was no way the bulb could do what it is doing. If the bulb is at fault then it is not the only fault (or so I assumed at any rate). The brand of the bulb is Philips but I cannot tell you more until I get home and look at it. I will post again later with fuller details and the result of a test in another location. Hi... Can't help wondering - it's not possible that one of those "switches" is a dimmer, is it? Take care. A good question but no. It is a landing light. There are three switches, one at each end and a third in the middle where a small corridor from the bathroom joins the landing. All simple on off switches (well they must be changeover switches but, from the user's point of view, they are just on off). And none are lighted switches? --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
Strange problem with low energy light bulb
Ron(UK) wrote:
Eeyore wrote: "Ron(UK)" wrote: If the neutral wire isn't properly grounded enough voltage can be induced by or leak from other 'live' circuits, maybe enough to cause the fluorescent fittings to randomly flicker. Ron, when the switch is off, there is no circuit. The neutral potential literally doesn't matter. Graham It`s a two way switch, there`s plenty of potential for leakage paths. You can easily get 100v on the neutral if it`s floating above earth potential. Ron(UK) Hmm. 2 way, 3 way , 4 way and any number of ways you want! why would that matter?, the neutral should not be part of the switching circuit. -- "I'm never wrong, once i thought i was, but was mistaken" Real Programmers Do things like this. http://webpages.charter.net/jamie_5 |
Strange problem with low energy light bulb
Eeyore writes:
Seán O'Leathlóbhair wrote: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. That would appear to be the case. This is at least partly true. Low energy lamps including compact fluorescents and normal fluorescents on electronic ballasts use a switching circuit to produce the high voltage for the fluorescent lamp. The input is a bridge rectifier and filter capacitor. Any source of AC even a small amount of leakage through a defective swtich, a switch with a neon lamp night light feature (lighted when off), an electronic timer, a motion sensor-controlled yard light, or a dimmer that isn't fully off, may cause the voltage to build up on the filter capacitor until the "startup circuit" kicks in. This usually has some sort of threshold de vice like a zener diode or diac that won't pass current until the voltage across it exceeds a spec'd value. When that happens, the lamp starts up and strikes but just for an instant since there isn't enough current available on the input to maintain it. I'm somewhat skeptical of the explanation with respect to inductive or capacitive coupling (though possible under just the right - or wrong - conditions) but it doesn't take that much leakage from some other fault to do this. --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
Strange problem with low energy light bulb
Eeyore writes:
PeterD wrote: Your switches are wired wrong (they are switching the neutral (or cold) side of the line, not the hot side. Makes no difference. When the switch is off, the circuit is broken. He said there are 2 or 3 switches controlling this lamp. In that case, there are a variety of ways that there could be capacitive and inductive coupling. Very often, there is a "traveller" with 2 parallel wires in it one of which is connected to the source and the other is connected to the lamp when it is off. --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
Strange problem with low energy light bulb
=?iso-8859-1?B?U2XhbiBPJ0xlYXRobPNiaGFpcg==?= writes:
Se=E1n O'Leathl=F3bhair wrote: I am not sure if this is an appropriate group for this question. If not, please suggest a better one. I have a light in the house which I have wanted to switch to a low energy bulb for a long time. The hold up was that I needed a very small bulb. At last, I have found a small enough bulb but something odd occurred as soon as I put it in. When it is switched on, it works as expected. When it is switched off, it blinks every few seconds. So, I guess that there must be a problem with the switch If it is passing nothing then it would seem impossible for the bulb to do anything. I did not notice any problem with the previous incandescent bulb but I guess that if the switch is leaking a tiny amount, the filament would glow too little to be seen. I have a few questions: What is going on? Is a tiny current leaking, building up a charge in a capacitor somewhere until a sufficient voltage builds up to spark in the bulb and discharge the capacitor, and then the cycle repeats. Is it safe? Will it wear out the bulb very fast? Is it likely to be enough to replace the switch? (Actually three switches can turn this bulb on and off). Might I have to replace the wiring? (Much harder than just replacing the switches) So many replies that it is hard to know which one to reply to so I will reply here. A curious feature that I forgot to mention is the regularlity of the flashes: every 2 seconds with no variation that I can detect with a stop watch. This is why I thought of a capacitor charging up until it reaches a critical voltage. But I was thinking of DC. AC is not going to charge up a capacitor over 2 seconds. What is inside these bulbs? A rectifier? A capacitor? No, you're correct. See my (and other) replies. It is a capacitor charging up - after a rectifier. --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. I will do some checking at the weekend. Climb into the loft space for a look. Get the multimeter out. Trying other low energy bulbs. Try the higher rated bulb. Etc. |
Strange problem with low energy light bulb
"William R. Walsh" m writes:
Hi! I have a few questions: What is going on? See my other reply. Do you have a light switch that glows when you turn it off? This will place a small amount of current flow across the lamp, which may make it flicker. Will it wear out the bulb very fast? It may result in a slight amount of wear on the bulb, but I doubt the change in lifetime would ever be noticed. This I wouldn't be so sure of. Startup is hard on fluorescent lamps. What is inside these bulbs? A rectifier? A capacitor? In many cases, these bulbs contain a small switchmode power supply. Such a power supply will have a transistor, some type of controller, a small transformer and some support components (of which a capacitor would probably be included). Others use a much simpler transformer design. The transformer design will not experience this phenomenon. --- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html Important: Anything sent to the email address in the message header above is ignored unless my full name AND either lasers or electronics is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
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