I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

On 12/11/2018 4:44 PM, wrote:
I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

Does the fixture wire it directly to the mains or does it have some kind
of switching, wireless, touch, dimmer, anything but direct wire to the
mains?

What's your definition of flicker?
Some bulbs have noticeable flicker at line frequency.
Most flicker at a much lower rate if you put some
electronics in the middle. It's the electronics that
expects the resistive load of an incandescent that flickers.

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

On Tuesday, December 11, 2018 at 6:44:07 PM UTC-6, wrote:
I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

I have some similar bulbs in a bathroom fixture. They flicker when the wife runs a certain curling iron on the same circuit. Is there anything else running on your lighting circuit?

On 12/12/18 00:44, wrote:
I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

Was the bulb holder designed for an LED or was it originally for a
filament bulb? Some of the smaller LEDs, such as G9, can overheat in a
non-ventilated holder. This can show as flickering; usually it's the
power control chip rather than the LEDs themselves which goes first. The
bulb will eventually fail.

--

Jeff

wrote:


I got a 60W Equliv.


** So about 11 watts power draw.


LED bulb in a fixture that flickers all the time.


** Try a different and newer fixture, the low current draw often requires the metal parts to be cleaner and freer of tarnish than is often the case.



My guess is a cheap electrolytic in the rectifier,


** Nuts.


..... Phil

On Wednesday, 12 December 2018 00:44:07 UTC, wrote:

I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

Tell us the nature of the flicker. Very fast & completely consistent would be a rectifier/smoothing issue. Irregular flicker would be a bad connection or less likely a dying LED.


NT

On Tue, 11 Dec 2018 18:40:21 -0700, KenW wrote:

On Tue, 11 Dec 2018 18:44:03 -0600, wrote:

I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

A buck or two ?
$1.77 ea at Home Depot (US Dollars)

KenW wrote:

A buck or two ?

Yeah but it depends where you live.

Here in Chicago you can walk in just about anywhere and expect to pay .99
to maybe $1.49 for a 60W led standard bulb.

The reason being, the local electric company got dick slapped for rate
increases which went to executive salaries, bahama vacations and golden
parachutes instead of the "infrastructure improvements" they claimed what
they were for. After the states attorney and citizens utility board got them
to audit their books, the truth came out.

So their rates were frozen for 10 years and then for a period of time I'm
not sure of, have to subsidize the costs of energy saving devices, which led
bulbs fall under. They also pay you $50 for replacing some older appliances.

I'm not sure they still do it, haven't looked, but like Home Depot even had
a special rack for the subsidized bulbs. I though it was odd but some of
them available were 100W incandesent ones, but they only used 80W of
electric but gave out the same amount of light. Those were considered energy
saving too.

It's about the only bargain with living in Chicago these days.

-bruce

I am presently managing replacement of all incandescent/fluorescent fixtures in just over 1,000,000 square feet of medical offices, research labs and a medical school on a single campus.

There are two parts of an LED lamp/fixture.

a) The LED emitters themselves: These are pretty generic beasts, and while not-quite-one-size-fits-all, the same emitter may provide light from between 3000K to 5000K. They are also pretty bullet-proof.

b) The "Driver" - which is a device that takes current from some source and makes it into what the emitters want for a particular type (Temperature and CRI) of output.

Common failure modes a

flickering - 90% - and what you are experiencing.
Massive RF output - 5% - so massive as to even step on cell phones and blue-tooth frequencies on rare occasions, but mostly lower bands.
*POOF* on start - 5%
Sometimes more than one fault per item.

Whereas these drivers are not delicate items, they fail often enough as that such a failure should surprise no one. Our installing contractor states that failures on commercial-grade devices are somewhere between 0.25% and 2.5% depending on the country-of-origin of the drivers, and where the devices are assembled. Consumer-grade devices experience a much higher failure rate.

Most failures occur within the first 4-6 hours of use.

Keep the receipt, and return the flickering item.

Peter Wieck
Melrose Park, PA

On Wednesday, 12 December 2018 13:26:18 UTC, wrote:

There are two parts of an LED lamp/fixture.

a) The LED emitters themselves: These are pretty generic beasts, and while not-quite-one-size-fits-all, the same emitter may provide light from between 3000K to 5000K. They are also pretty bullet-proof.

in excellent quality lamps maybe. Not at all bullet-proof in domestic LED lights.


NT

On Wednesday, December 12, 2018 at 9:37:20 AM UTC-5, wrote:
On Wednesday, 12 December 2018 13:26:18 UTC, wrote:

There are two parts of an LED lamp/fixture.

a) The LED emitters themselves: These are pretty generic beasts, and while not-quite-one-size-fits-all, the same emitter may provide light from between 3000K to 5000K. They are also pretty bullet-proof.

in excellent quality lamps maybe. Not at all bullet-proof in domestic LED lights.


Possibly true, but the failure mode of an emitter is not flicker.

Peter Wieck
Melrose Park, PA

On Wednesday, 12 December 2018 15:18:52 UTC, wrote:
On Wednesday, December 12, 2018 at 9:37:20 AM UTC-5, tabby wrote:
On Wednesday, 12 December 2018 13:26:18 UTC, wrote:

There are two parts of an LED lamp/fixture.

a) The LED emitters themselves: These are pretty generic beasts, and while not-quite-one-size-fits-all, the same emitter may provide light from between 3000K to 5000K. They are also pretty bullet-proof.

in excellent quality lamps maybe. Not at all bullet-proof in domestic LED lights.


Possibly true, but the failure mode of an emitter is not flicker.

Peter Wieck
Melrose Park, PA

sometimes it is, but more often not.


NT

As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

On Wednesday, 12 December 2018 16:00:17 UTC, wrote:

As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I know you think you're right about everything, but you're not. LEDs do sometimes go into flickering mode. You could go google if you don't believe me, it's not that hard to do.


NT

On Wednesday, December 12, 2018 at 12:16:11 PM UTC-5, wrote:

I know you think you're right about everything, but you're not. LEDs do sometimes go into flickering mode. You could go google if you don't believe me, it's not that hard to do.

Where does flicker come from?
To better understand flickering in lights, consider the theatrical effect known as strobe lighting. This is a deliberate flicker effect that delivers light at certain frequencies, causing the brain to interpret moving objects as if they were in slow motion. These specified frequencies are generally just a few flashes per second, but they are very close to frequencies that cause epileptic seizures.

Unintentional flickering in lighting equipment can be traced back to our power companies that designed electricity flow to use alternating current (AC) as opposed to direct current (DC). With AC power, the sine wave will peak both positively and negatively. This leaves it susceptible to being in a range that will cause flickering, or sometimes an audible hum.

How to solve LED flickering issues?
LED flickering can be tied back to the driver component within the lamp. The essential purpose of the LED driver design is to rely on a simple circuit to control output current, but without altering the frequency, the LED becomes likely to show visible flicker. However, this can be fixed by using constant current drivers, which remove the peaks of the sine wave.





Power correction components within the driver circuit must also be addressed. Without this, ripple currents in the power flow will cause flickering.

Ultimately if the driver design of the LED bulb meets the requirements of both a stable DC current and ample ripple suppression, there should be no flicker. If flickering is present in your LED lamp (and you are not dimming with it), it was likely created with cheap driver components. The technology in LED lighting has advanced to the point where this should not happen, unfortunately there are companies that care more about their bottom line than the health of their customers.

How Dimming Causes LED Flickering
Another challenging variable for LED lamps to avoid flickering is through dimming. Most standard wall dimmers work by phase cutting, which removes part of the sine wave and reduces the voltage. However, this can have negative affects on an LED circuit and actually result in the flicker effect being amplified to a potentially dangerous level (3-15Hz range).

This is one of the main reasons why its hard to trust old dimming systems with new LED bulbs. The only way to be sure no flickering will be present is to get LED-specific dimming solutions for your LED lamps. It all comes back to the fact that LED is a long-term investment. In turn it is worth doing research to ensure you are getting a quality LED bulb, and that if you plan to dim with it you are getting an LED dimming system that has been tested as being compatible to the LED bulbs you intend to use.
__________________________________________________ _______________________

Now, show us a link where the emitter is the cause of the flicker, and not the driver.

Otherwise, understand that the Bellman's Proof is not a valid argument.

Peter Wieck
Melrose Park, PA

On Wednesday, 12 December 2018 17:26:36 UTC, wrote:
On Wednesday, December 12, 2018 at 12:16:11 PM UTC-5, tabby wrote:

I know you think you're right about everything, but you're not. LEDs do sometimes go into flickering mode. You could go google if you don't believe me, it's not that hard to do.

Where does flicker come from?
To better understand flickering in lights, consider the theatrical effect known as strobe lighting. This is a deliberate flicker effect that delivers light at certain frequencies, causing the brain to interpret moving objects as if they were in slow motion. These specified frequencies are generally just a few flashes per second, but they are very close to frequencies that cause epileptic seizures.

Unintentional flickering in lighting equipment can be traced back to our power companies that designed electricity flow to use alternating current (AC) as opposed to direct current (DC). With AC power, the sine wave will peak both positively and negatively. This leaves it susceptible to being in a range that will cause flickering, or sometimes an audible hum.

How to solve LED flickering issues?
LED flickering can be tied back to the driver component within the lamp. The essential purpose of the LED driver design is to rely on a simple circuit to control output current, but without altering the frequency, the LED becomes likely to show visible flicker. However, this can be fixed by using constant current drivers, which remove the peaks of the sine wave.





Power correction components within the driver circuit must also be addressed. Without this, ripple currents in the power flow will cause flickering.

Ultimately if the driver design of the LED bulb meets the requirements of both a stable DC current and ample ripple suppression, there should be no flicker. If flickering is present in your LED lamp (and you are not dimming with it), it was likely created with cheap driver components. The technology in LED lighting has advanced to the point where this should not happen, unfortunately there are companies that care more about their bottom line than the health of their customers.

How Dimming Causes LED Flickering
Another challenging variable for LED lamps to avoid flickering is through dimming. Most standard wall dimmers work by phase cutting, which removes part of the sine wave and reduces the voltage. However, this can have negative affects on an LED circuit and actually result in the flicker effect being amplified to a potentially dangerous level (3-15Hz range).

This is one of the main reasons why its hard to trust old dimming systems with new LED bulbs. The only way to be sure no flickering will be present is to get LED-specific dimming solutions for your LED lamps. It all comes back to the fact that LED is a long-term investment. In turn it is worth doing research to ensure you are getting a quality LED bulb, and that if you plan to dim with it you are getting an LED dimming system that has been tested as being compatible to the LED bulbs you intend to use.
__________________________________________________ _______________________

Now, show us a link where the emitter is the cause of the flicker, and not the driver.

Otherwise, understand that the Bellman's Proof is not a valid argument.

Peter Wieck
Melrose Park, PA

Man you can be stupid. Go educate yourself. Or not.

Thought not.

Peter Wieck
Melrose Park, PA

On Wednesday, 12 December 2018 17:47:10 UTC, wrote:
Thought not.

Peter Wieck
Melrose Park, PA

you've earnt your ignorance and you get to keep it.

On Wednesday, December 12, 2018 at 2:00:49 PM UTC-5, wrote:
On Wednesday, 12 December 2018 17:47:10 UTC, wrote:
Thought not.

Peter Wieck
Melrose Park, PA

you've earnt your ignorance and you get to keep it.

For someone who rears up like an injured virgin when called out, you have lost a priceless opportunity to humiliate your oppressor.

That would be earned. Whereas Earnt is correct, it is non-standard and somewhat pretentious. Similar to your inferred virginity.

Peter Wieck
Melrose Park, PA

On Wednesday, 12 December 2018 19:09:19 UTC, wrote:
On Wednesday, December 12, 2018 at 2:00:49 PM UTC-5, tabby wrote:
On Wednesday, 12 December 2018 17:47:10 UTC, wrote:
Thought not.

Peter Wieck
Melrose Park, PA

you've earnt your ignorance and you get to keep it.

For someone who rears up like an injured virgin when called out, you have lost a priceless opportunity to humiliate your oppressor.

That would be earned. Whereas Earnt is correct, it is non-standard and somewhat pretentious. Similar to your inferred virginity.

Peter Wieck
Melrose Park, PA

It seems I overestimated you.

On 12/12/2018 8:00 AM, wrote:
As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I love it when people say "full stop" like that makes 'em right.
So, you've never seen a thermal intermittent...

Unlikely, maybe. Full Stop, not so much.

On Wednesday, December 12, 2018 at 3:07:34 PM UTC-5, mike wrote:
On 12/12/2018 8:00 AM, wrote:
As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I love it when people say "full stop" like that makes 'em right.
So, you've never seen a thermal intermittent...

Unlikely, maybe. Full Stop, not so much.

A thermal intermittent would not apply to the emitter. It would very much apply to the driver, socket, contacts, whatever. I have seen my fair share, naturally - and none of them were an emitter fault.

Peter Wieck
Melrose Park, PA

On 12/12/18 11:26 AM, wrote:
Another challenging variable for LED lamps to avoid flickering
is through dimming.

Surprisingly, the two cheap 60 Watt dimmable LEDs I bought at Walmart,
work just fine with the old photo cell socket "night light" adapters.
Designed to work with incandescent bulbs, I found out they only take
month or two to kill halogen bulbs.

--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

On Wednesday, December 12, 2018 at 9:26:36 AM UTC-8, wrote:
On Wednesday, December 12, 2018 at 12:16:11 PM UTC-5, wrote:

I know you think you're right about everything, but you're not. LEDs do sometimes go into flickering mode.

Now, show us a link where the emitter is the cause of the flicker, and not the driver.

On Wednesday, December 12, 2018 at 9:26:36 AM UTC-8, wrote:
On Wednesday, December 12, 2018 at 12:16:11 PM UTC-5, wrote:

I know you think you're right about everything, but you're not. LEDs do sometimes go into flickering mode.

Now, show us a link where the emitter is the cause of the flicker, and not the driver.

Oh, it happens; I've had multi-LED panels where handling the PC board (not the power
brick) caused/stopped the flicker. Not solder, either, some kind of internal-to-the-LED
package or thermal fault. Replaced four or five elements, and the lamp works fine now
(though my replacement LEDs were a mismatch for the original 'warm' white).

I know you think you're right about everything, but you're not. LEDs do sometimes go into flickering mode.

Now, show us a link where the emitter is the cause of the flicker, and not the driver.

Oh, it happens; I've had multi-LED panels where handling the PC board (not the power
brick) caused/stopped the flicker. Not solder, either, some kind of internal-to-the-LED
package or thermal fault. Replaced four or five elements, and the lamp works fine now
(though my replacement LEDs were a mismatch for the original 'warm' white).

A lot of the cheap Chinese-made LED bulbs for automotive use seem to
develop flicker problems. One or more series strings of LEDs start
flashing on and off, somewhat randomly, while other strings are
unaffected. These don't have a "driver" per se, just a series
resistor and (in some cases) a bypass cap.

I haven't been able to tell whether the failure is in one of the
individual LEDs in the string, or in the solder bonding of the LED to
the substrate. I sorta suspect the latter... bad RoHS-safe-solder
junctions, perhaps. The flickering seems to be at least partially a
thermal cycling problem... LED comes on, chip heats up, bad junction
opens, LED cools down, lather/rinse/repeat.

The time constant is typically a fraction of a second... more of a
blink than a flicker.

On Wednesday, December 12, 2018 at 3:44:41 PM UTC-5, wrote:
On Wednesday, December 12, 2018 at 3:07:34 PM UTC-5, mike wrote:
On 12/12/2018 8:00 AM, wrote:
As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I love it when people say "full stop" like that makes 'em right.
So, you've never seen a thermal intermittent...

Unlikely, maybe. Full Stop, not so much.

A thermal intermittent would not apply to the emitter. It would very much apply to the driver, socket, contacts, whatever. I have seen my fair share, naturally - and none of them were an emitter fault.

Peter Wieck
Melrose Park, PA



I've seen plenty of intermittent or even slow to start LED emitter chips. In LCD backlights, I've changed over two thousand of them in the last 5 years.

But, the majority of those were either shorted or open, but the intermittent ones busted my ass enough to force a change of procedure in bench testing before the display was reassembled. Several thermal cycles as well as under-volting and over-volting the array will ferret out most intermittents.

On Wednesday, December 12, 2018 at 8:11:10 PM UTC-5, John-Del wrote:
On Wednesday, December 12, 2018 at 3:44:41 PM UTC-5, wrote:
On Wednesday, December 12, 2018 at 3:07:34 PM UTC-5, mike wrote:
On 12/12/2018 8:00 AM, wrote:
As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I love it when people say "full stop" like that makes 'em right.
So, you've never seen a thermal intermittent...

Unlikely, maybe. Full Stop, not so much.

A thermal intermittent would not apply to the emitter. It would very much apply to the driver, socket, contacts, whatever. I have seen my fair share, naturally - and none of them were an emitter fault.

Peter Wieck
Melrose Park, PA



I've seen plenty of intermittent or even slow to start LED emitter chips. In LCD backlights, I've changed over two thousand of them in the last 5 years.

But, the majority of those were either shorted or open, but the intermittent ones busted my ass enough to force a change of procedure in bench testing before the display was reassembled. Several thermal cycles as well as under-volting and over-volting the array will ferret out most intermittents.

I forgot to add that in no case have I seen an LED chip "flicker", at least not in a steady cadence. OP never clarified what exact kind of flicker he had but I think we've gotten off the subject a bit.

In article ,
wrote:
Now, show us a link where the emitter is the cause of the flicker, and not the driver.

A Practical Example of GaN-LED Failure Cause Analysis by Application of Combined Electron
Microscopy Techniques

Page 2: ...after a short time, the blue and white LEDs either started to flicker, showed a
reduced light output, or spontaneously failed completely, whereas the red LEDs present in
the same module in parallel continued to function correctly.

Page 4: The further observation of cross-sections of the nitride layers inside revealed the
reasons for the devices malfunctions. In Figure 4, an example of a cross-section of an
LED exhibiting failure type (B) (flickering dark and bright) is shown. One can see that
beside the bond foot, the nitride semiconductor layer has slightly lost contact to the back
side of the device and, moreover, shows tiny cracks across the layer.

http://www.mdpi.com/1996-1944/10/10/1202/pdf

Sceptre
--

SDF Public Access UNIX System - http://sdf.org

On Tue, 11 Dec 2018 18:23:45 -0800, mike wrote:

On 12/11/2018 4:44 PM, wrote:
I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

Does the fixture wire it directly to the mains or does it have some kind
of switching, wireless, touch, dimmer, anything but direct wire to the
mains?

What's your definition of flicker?
Some bulbs have noticeable flicker at line frequency.
Most flicker at a much lower rate if you put some
electronics in the middle. It's the electronics that
expects the resistive load of an incandescent that flickers.

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.


I have it in my hallway. Standard switch only, no dimmer. Fixture is a
common "BOOB LIGHT". (Google that). I haave 3 such fixtures in the
house, all have LEDs. Only this one in the hallway flickers. Neither the
incan bulb or CFL that used to be in that fixture flickered. So its
likely the LED bulb. I bought a bunch of them at Walmart and then Dollar
Tree was selling some for ONE DOLLAR (US) for TWO PACK. I stocked up.
I am not sure which is in this fixture, but no others flicker from
either store.....

On 12/13/18 2:58 AM, wrote:
I bought a bunch of them at Walmart and then Dollar
Tree was selling some for ONE DOLLAR (US) for TWO PACK. I stocked up.
I am not sure which is in this fixture, but no others flicker from
either store.....

So, why don't ya just replace the thing and be done with it?

--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Am 12.12.2018 um 01:44 schrieb :
I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.


If the bulb has an capacitive power supply could be a defective
rectifier leeds to flickering.

In article ,
says...

On 12/13/18 2:58 AM, wrote:
I bought a bunch of them at Walmart and then Dollar
Tree was selling some for ONE DOLLAR (US) for TWO PACK. I stocked up.
I am not sure which is in this fixture, but no others flicker from
either store.....

So, why don't ya just replace the thing and be done with it?



My thoughts too. I have a celaing fan with 4 bulbs in it. I put LEDs
in it a while back replacing the CFLs. I seldom use the fan part, bu
the lights stay on from about 9 in the morning to 12 at night almost
every day. A few days ago one of the LEDs would go off for about 2
seconds and come on for a short time and off again. I just replaced it.
I may open it up just to see one day, but have not taken time to even
worry about it. It may have been of the free ones the power company was
giving out a few years ago. At one time they gave out about a dozen CFL
and then a dozen LEDs a few years later.

One and two dollar or less items are just not worth the time to worry
about when they last over 6 months.

On 12/12/2018 5:13 PM, John-Del wrote:
On Wednesday, December 12, 2018 at 8:11:10 PM UTC-5, John-Del wrote:
On Wednesday, December 12, 2018 at 3:44:41 PM UTC-5, wrote:
On Wednesday, December 12, 2018 at 3:07:34 PM UTC-5, mike wrote:
On 12/12/2018 8:00 AM, wrote:
As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I love it when people say "full stop" like that makes 'em right.
So, you've never seen a thermal intermittent...

Unlikely, maybe. Full Stop, not so much.

A thermal intermittent would not apply to the emitter. It would very much apply to the driver, socket, contacts, whatever. I have seen my fair share, naturally - and none of them were an emitter fault.

Peter Wieck
Melrose Park, PA



I've seen plenty of intermittent or even slow to start LED emitter chips. In LCD backlights, I've changed over two thousand of them in the last 5 years.

But, the majority of those were either shorted or open, but the intermittent ones busted my ass enough to force a change of procedure in bench testing before the display was reassembled. Several thermal cycles as well as under-volting and over-volting the array will ferret out most intermittents.

I forgot to add that in no case have I seen an LED chip "flicker", at least not in a steady cadence. OP never clarified what exact kind of flicker he had but I think we've gotten off the subject a bit.

I've had bad luck, irregular flicking - with one brand of LED
'40w''candelabra' bulbs in which the 'filaments' were plainly visible
In the bulb - glass envelope - some filaments flickered while others
were fine. Occurred in 4 different bulbs. As I recall each bulb had
4 strings (filaments) of LEDs. Sorry, I don't remember the brand.

On Thu, 13 Dec 2018 15:33:54 -0800, Bennett Price
wrote:

On 12/12/2018 5:13 PM, John-Del wrote:
On Wednesday, December 12, 2018 at 8:11:10 PM UTC-5, John-Del wrote:
On Wednesday, December 12, 2018 at 3:44:41 PM UTC-5, wrote:
On Wednesday, December 12, 2018 at 3:07:34 PM UTC-5, mike wrote:
On 12/12/2018 8:00 AM, wrote:
As an LED is a go/no-go device, flicker is indicative of a condition outside the emitter. Full stop.

Peter Wieck
Melrose Park, PA

I love it when people say "full stop" like that makes 'em right.
So, you've never seen a thermal intermittent...

Unlikely, maybe. Full Stop, not so much.

A thermal intermittent would not apply to the emitter. It would very much apply to the driver, socket, contacts, whatever. I have seen my fair share, naturally - and none of them were an emitter fault.

Peter Wieck
Melrose Park, PA



I've seen plenty of intermittent or even slow to start LED emitter chips. In LCD backlights, I've changed over two thousand of them in the last 5 years.

But, the majority of those were either shorted or open, but the intermittent ones busted my ass enough to force a change of procedure in bench testing before the display was reassembled. Several thermal cycles as well as under-volting and over-volting the array will ferret out most intermittents.

I forgot to add that in no case have I seen an LED chip "flicker", at least not in a steady cadence. OP never clarified what exact kind of flicker he had but I think we've gotten off the subject a bit.

I've had bad luck, irregular flicking - with one brand of LED
'40w''candelabra' bulbs in which the 'filaments' were plainly visible
In the bulb - glass envelope - some filaments flickered while others
were fine. Occurred in 4 different bulbs. As I recall each bulb had
4 strings (filaments) of LEDs. Sorry, I don't remember the brand.
Same here. Out of 6 Sylvania candelabra bulbs, 3 did the exact same
thing. Replaced with a different brand and no flickering.

On Tuesday, December 11, 2018 at 7:44:07 PM UTC-5, wrote:
I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

This is my opinion. They are made very cheaply they aren't made with much shielding so anything can cause them to flicker. Now be careful because cans have protection from overheating and it's possible the LED module is not compatible with the model of can fixture you have so that's another possibility. I would try another unit see how things go.

On Sunday, 16 December 2018 20:46:34 UTC, wrote:
On Tuesday, December 11, 2018 at 7:44:07 PM UTC-5, wrote:

I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

This is my opinion. They are made very cheaply they aren't made with much shielding so anything can cause them to flicker.

that simply isn't so. The nature of the circuits makes them robust against RFI.


NT

On Wednesday, December 12, 2018 at 8:26:18 AM UTC-5, wrote:
There are two parts of an LED lamp/fixture.

a) The LED emitters themselves: These are pretty generic beasts, and while not-quite-one-size-fits-all, the same emitter may provide light from between 3000K to 5000K. They are also pretty bullet-proof.

b) The "Driver" - which is a device that takes current from some source and makes it into what the emitters want for a particular type (Temperature and CRI) of output.

Massive RF output - 5% - so massive as to even step on cell phones and blue-tooth frequencies on rare occasions, but mostly lower bands.

Hmm. Our Christmas tree has a couple hundred LED lights on it. Am I broadcasting RF to the neighborhood?

On Monday, December 17, 2018 at 11:11:28 AM UTC-5, Tim R wrote:
On Wednesday, December 12, 2018 at 8:26:18 AM UTC-5, wrote:
There are two parts of an LED lamp/fixture.

a) The LED emitters themselves: These are pretty generic beasts, and while not-quite-one-size-fits-all, the same emitter may provide light from between 3000K to 5000K. They are also pretty bullet-proof.

b) The "Driver" - which is a device that takes current from some source and makes it into what the emitters want for a particular type (Temperature and CRI) of output.

Massive RF output - 5% - so massive as to even step on cell phones and blue-tooth frequencies on rare occasions, but mostly lower bands.

Hmm. Our Christmas tree has a couple hundred LED lights on it. Am I broadcasting RF to the neighborhood?

Depends on the driver. You would know if you were.

Peter Wieck
Melrose Park, PA

On Sunday, December 16, 2018 at 4:25:43 PM UTC-5, wrote:
On Sunday, 16 December 2018 20:46:34 UTC, wrote:
On Tuesday, December 11, 2018 at 7:44:07 PM UTC-5, wrote:

I got a 60W Equliv. LED bulb in a fixture that flickers all the time.
Its not very old. It does produce enough light but gets annoying after
awhile. They only cost a buck or two, so i'll just replace it, but I
wonder what is causing the flicker?

My guess is a cheap electrolytic in the rectifier, but I have never
really seen a schematic for how they are wired.

This is my opinion. They are made very cheaply they aren't made with much shielding so anything can cause them to flicker.

that simply isn't so. The nature of the circuits makes them robust against RFI.


NT

Nevermind my comment on RF. I had my thought train crossing.

I do think these are made cheaply and they would have to be in order to turn a profit. As far as RF, nah that isn't going to cause flicker. The bulb itself is DC and if there was any RF it would simply be super imposed onto a DC bias which the amplitude from any RFI would be so insignificant and wouldn't matter because well it's a diode. The driver shouldn't respond to RFI because it's an AC/DC converter and the DC is probably being switched which alone would cause RF. Just the AC is creating a field. I really couldn't say exactly what is causing the flicker because I am not present to check the entire circuit. As far as what can cause it. Bad wiring, bad can, bad bulb, corrosion, bulb not installed all the way. Things of that nature. Could be a bad solder joint. I have a Saab which has a bulb out detector. These are notorious for bad solder joints and the symptoms are a headlamp bulb that can flicker or come on and out and you know it all responds to vibration and of course temperature for obvious reasons.

Bring back that cheaply made stuff. Yeah they aren't exactly made to last forever because you need to consider the planned obsolesce part. Yes they have been known to last 10+ years but not all of them do and it is because of chance or was it designed to? One can pickup these 60W equivalent 2 packs in HD for 5 bucks when they are on clearance. The retailer still makes a profit the distributor makes a profit the designer, etc. Everyone still gets their money. Maybe not the amount they had in mind by they never give away anything.

My worthless 2 cents