I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

Jimmie

JIMMIE wrote in news:2e634943-f451-4731-b06f-
:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

Jimmie


Why did you take it apart? They are pricey and have lives rated at 10k-30k
hrs. All bulbs at this point should be under warranty. I could see the
curiousity angle if they were a couple of bucks.

On 1/2/2012 5:46 PM, Red Green wrote:
wrote in news:2e634943-f451-4731-b06f-
:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

Jimmie


Why did you take it apart? They are pricey and have lives rated at 10k-30k
hrs. All bulbs at this point should be under warranty. I could see the
curiousity angle if they were a couple of bucks.

You must have not purchased any lately because just a few nights ago I
purchased 4 23 watt CFL's at Menards for $7.92 and they were not even on
sale!

Don

Red Green wrote:

JIMMIE wrote in news:2e634943-f451-4731-b06f-
:

I just took apart a failed LED bulb replacement. The circuitry appears
{snip}

Why did you take it apart? They are pricey and have lives rated at 10k-30k
hrs. All bulbs at this point should be under warranty.

I bought a Feit LED night light. It should've lasted forever but
failed after one week. Warranty required that I mail it to them
at my expense; which would've cost more than the light did.

I went back to an incandescent night light, and I don't buy Feit
products any more.

JIMMIE wrote:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

But low voltage wiring won't eliminate the electronics, unless just a
simple resistor is put in series with each LED (probably not so energy
efficient), because LEDs need current-regulated power supplies, just
as CFLs do (but at higher voltage).

Here's a CFL disected:

http://shaddack.twibright.com/projects/reveng_cfl/

IGot2P wrote in
:

On 1/2/2012 5:46 PM, Red Green wrote:
wrote in
news:2e634943-f451-4731-b06f-
:

I just took apart a failed LED bulb replacement. The circuitry
appears fairly complex using caps diodes and active components
Complex relative to a circuit that is just a rectifier and current
limiting resistor. While the LEDs themselves may have high
reliability I think the failing point is going to be the power
supply and I am not expecting them to have much better reliability
than CFLs. I do think there is a future for home LED lighting that
will come when buildings are wired for low voltage lighting that
removes the 120 VAC to low voltage DC power supplies from the bulbs.

Jimmie


Why did you take it apart? They are pricey and have lives rated at
10k-30k hrs. All bulbs at this point should be under warranty. I
could see the curiousity angle if they were a couple of bucks.

You must have not purchased any lately because just a few nights ago I
purchased 4 23 watt CFL's at Menards for $7.92 and they were not even
on sale!

Don


I read it as he took apart a failed LED bulb. It's the subject too.

On 1/2/2012 8:26 PM, larry moe 'n curly wrote:


JIMMIE wrote:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

But low voltage wiring won't eliminate the electronics, unless just a
simple resistor is put in series with each LED (probably not so energy
efficient), because LEDs need current-regulated power supplies, just
as CFLs do (but at higher voltage).

Here's a CFL disected:

http://shaddack.twibright.com/projects/reveng_cfl/

New light bulbs look more complex than my first computer

On Jan 3, 8:54*am, Frank wrote:
On 1/2/2012 8:26 PM, larry moe 'n curly wrote:





JIMMIE wrote:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability *than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

But low voltage wiring won't eliminate the electronics, unless just a
simple resistor is put in series with each LED (probably not so energy
efficient), because LEDs need current-regulated power supplies, just
as CFLs do (but at higher voltage).

Here's a CFL disected:

* *http://shaddack.twibright.com/projects/reveng_cfl/

New light bulbs look more complex than my first computer - Hide quoted text -

- Show quoted text -

I've been skeptical as to the duration of LED lights
for exactly those reasons and because of experience
with CFLs. I think the huge hours claimed on LED
packages is based on the core LED semiconductor
technology, not the actual lamps themselves, which
obviously include other electronics. Even the LEDs
are probably made in China and I would suspect would
not last as long as a Japanese LED in a typical
consumer appliance. But we shall see.

On Jan 2, 6:46*pm, Red Green wrote:
JIMMIE wrote in news:2e634943-f451-4731-b06f-
:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability *than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

Jimmie

Why did you take it apart? They are pricey and have lives rated at 10k-30k
hrs. All bulbs at this point should be under warranty. I could see the
curiousity angle if they were a couple of bucks.

The bulb was from work and they were nt going for the refund so it
just became curiosity to me. Processing the refund becomes more
expensive than the bulb. Not the first LED lights we had with this
problem. First we tried were for stairwell lighting. Two of the 3
failed within about 6 months. Failure analysis showed it was the power
supply. Since the stairwell was on its on breaker we opted to build a
LVDC power supply for the lights and bypass the existing power supply.
That was 3 years ago and there have been no more failures. I think LED
lighting as a direct replacement for existing lights is a big mistake
as the built in power supplies will always s be the weak link.


Jimmie

On Jan 2, 8:26*pm, "larry moe 'n curly"
wrote:
JIMMIE wrote:

I just took apart a failed LED bulb replacement. The circuitry appears
fairly complex using caps diodes and active components Complex
relative to a circuit that is just a rectifier and current limiting
resistor. While the LEDs themselves may have high reliability I think
the failing point is going to be the power supply and I am not
expecting them to have much better reliability *than CFLs. I do think
there is a future for home LED lighting that will come when buildings
are wired for low voltage lighting that removes the 120 VAC to low
voltage DC power supplies from the bulbs.

But low voltage wiring won't eliminate the electronics, unless just a
simple resistor is put in series with each LED (probably not so energy


No, but it can be much better quality using a transformer or a
switching power supply, ( very efficient) and not have to be
duplicated for every light. We have low voltage power supplies that
have been running for 20+ years 24/7.

On 1/3/2012 5:51 PM, wrote:
On Tue, 3 Jan 2012 09:50:18 -0800 (PST), "
wrote:

I've been skeptical as to the duration of LED lights
for exactly those reasons and because of experience
with CFLs. I think the huge hours claimed on LED
packages is based on the core LED semiconductor
technology, not the actual lamps themselves, which
obviously include other electronics. Even the LEDs
are probably made in China and I would suspect would
not last as long as a Japanese LED in a typical
consumer appliance. But we shall see.

Exactly. The LEDs themselves are made to last many years (althought I
doubt the cheap China ones will), but the rest of the components in
the power supply (especially capacitors) wont last that long.

On the other hand, I would bet that the LED flashlights that run on
batteries WILL last that long, providing they are not damaged in other
ways, or have battery leakage that wrecks them from corrosion.
Most of them will have switch failure though..... Yet they still
outlast the old filament type falshlights that never seemed to last
more than a few months, except for the most costly models.


That's what I would figure. I had a squeeze light led that just
contained led and battery. The switch did get out of whack but bulb
still works. Hopefully the better lights don't have all this spinach.

JIMMIE wrote in
:

On Jan 2, 6:46*pm, Red Green wrote:
JIMMIE wrote in
news:2e634943-f451-4731-b06f-
:

I just took apart a failed LED bulb replacement. The circuitry
appears fairly complex using caps diodes and active components
Complex relative to a circuit that is just a rectifier and current
limiting resistor. While the LEDs themselves may have high
reliability I think the failing point is going to be the power
supply and I am not expecting them to have much better reliability
*than CFLs. I do think there is a future for home LED lighting that
will come when buildings are wired for low voltage lighting that
removes the 120 VAC to low voltage DC power supplies from the
bulbs.

Jimmie

Why did you take it apart? They are pricey and have lives rated at
10k-30
k
hrs. All bulbs at this point should be under warranty. I could see
the curiousity angle if they were a couple of bucks.

The bulb was from work and they were nt going for the refund so it
just became curiosity to me. Processing the refund becomes more
expensive than the bulb.

Makes sense. I woulda done the same. I hacked up my first CFL with the HF
MF tool. Piece O' Cake and clean. Yet another HF success story :-)

Not the first LED lights we had with this
problem. First we tried were for stairwell lighting. Two of the 3
failed within about 6 months. Failure analysis showed it was the power
supply. Since the stairwell was on its on breaker we opted to build a
LVDC power supply for the lights and bypass the existing power supply.
That was 3 years ago and there have been no more failures. I think LED
lighting as a direct replacement for existing lights is a big mistake
as the built in power supplies will always s be the weak link.


Jimmie

On Tue, 03 Jan 2012 16:51:09 -0600, wrote:

On Tue, 3 Jan 2012 09:50:18 -0800 (PST), "
wrote:

I've been skeptical as to the duration of LED lights
for exactly those reasons and because of experience
with CFLs. I think the huge hours claimed on LED
packages is based on the core LED semiconductor
technology, not the actual lamps themselves, which
obviously include other electronics. Even the LEDs
are probably made in China and I would suspect would
not last as long as a Japanese LED in a typical
consumer appliance. But we shall see.

Exactly. The LEDs themselves are made to last many years (althought I
doubt the cheap China ones will), but the rest of the components in
the power supply (especially capacitors) wont last that long.

On the other hand, I would bet that the LED flashlights that run on
batteries WILL last that long, providing they are not damaged in other
ways, or have battery leakage that wrecks them from corrosion.
Most of them will have switch failure though..... Yet they still
outlast the old filament type falshlights that never seemed to last
more than a few months, except for the most costly models.

Don't discount heat. So far they've been making a mess of the thermal design.
Just look at traffic lights and you'll see tons of burned-out LEDs, after only
a couple of years (should last decades).