LED modifications that have a warning...why?

[eccerr0r]

Well it goes without saying but you shouldn't modify electronics at the risk of causing unintended consequences. However I saw an explicit warning to purchasers of an LED bulb saying this:

"Caution: Changes or modification not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment"

Then it goes on to say that it meets FCC part 15 rules, class B, which it should.

Now the question that the warning leads to... What modification are they talking about? What magical modification would make the LED better? Were people making LEDs into broadband noise makers or something, but why now and not with CFL bulbs? Why isn't this warning on other consumer equipment, heck, radio transmitters, CB, FRS, etc., which are more obvious?

[sam_sam_sam]

Re: LED modifications that have a warning...why?

Well it goes without saying but you shouldn't modify electronics at the risk of causing unintended consequences. However I saw an explicit warning to purchasers of an LED bulb saying this:

"Caution: Changes or modification not expressly approved by the party responsible for compliance could void the user's authority to operate the equipment"

Then it goes on to say that it meets FCC part 15 rules, class B, which it should.

Now the question that the warning leads to... What modification are they talking about? What magical modification would make the LED better? Were people making LEDs into broadband noise makers or something, but why now and not with CFL bulbs? Why isn't this warning on other consumer equipment, heck, radio transmitters, CB, FRS, etc., which are more obvious?

What product was this on I would like to know

Thanks

[stj]

Re: LED modifications that have a warning...why?

in some country's the communists are getting touchy now about Power Factor.
maybe that's it

[eccerr0r]

Re: LED modifications that have a warning...why?

This was on an individual LED light bulb 60W equivalent (8W used), an A19 replacement with E26(?) medium base.

The Power Factor clause is a good guess, but how would it benefit the end user?

Strange eh?

[stj]

Re: LED modifications that have a warning...why?

nothing ever benifits the end user - they dont give a fuck about us.

[eccerr0r]

Re: LED modifications that have a warning...why?

Then why put the warning that would discourage purchasers?

[stj]

Re: LED modifications that have a warning...why?

because poor power factor costs the power company.

in short, we are being blamed and penalised for the fact that their infrastructure is not designed to handle non-unity power consumpion.
and yet *they* are the fuckers that told us to use switching psu's and "energy saving" lamps!

they need to switch to DC high voltage distribution with substation inverters supplying AC over the last mile or less to the user.
the tech exists and is comercial - it's also cheaper if starting from scratch - but they arent starting from scratch.

[redwire]

Re: LED modifications that have a warning...why?

The warning is a mandatory (user manual) requirement by the FCC. It appears on everything, from wireless headphones, radios, led light bulbs...
It seems to be saying if you change cabling on your product, it could upset the product's (passed testing) "unintentional radiator" and cause (new) interference that is your problem.

For an LED light bulb, you don't know how long the wiring to it is. If FCC testing is 1m/3ft and in your house it's 5.1m/17ft or something that is a wavelength of some radio station, your LED light bulb can end up transmitting RF hash now - yet it passed testing.


Grid power factor is usually lagging, so they need to add capacitor banks to help correct it. It's a bit of a substitute for ever increasing loads on old infrastructure. I worked on projects adding cap banks to substations, the caps and breakers are very expensive.

[eccerr0r]

Re: LED modifications that have a warning...why?

because poor power factor costs the power company.

in short, we are being blamed and penalised for the fact that their infrastructure is not designed to handle non-unity power consumpion.
and yet *they* are the fuckers that told us to use switching psu's and "energy saving" lamps!

they need to switch to DC high voltage distribution with substation inverters supplying AC over the last mile or less to the user.
the tech exists and is comercial - it's also cheaper if starting from scratch - but they arent starting from scratch.

but what can you do to the LED that would ruin its power factor and make it work better for the end user? I don't see a mod that would make the LED work "better" while sacrificing PF?

The warning is a mandatory (user manual) requirement by the FCC. It appears on everything, from wireless headphones, radios, led light bulbs...

Yes, this is what I would expect. Why I don't see this warning on everything is what bothers me - this is the first time I saw something like this, and on a silly LED bulb no less!

I would have to think that anything that needs some sort of FCC approval, whether it's part 15 or part 95, must have this warning. Perhaps it was a recent rule that was added and I should expect to see this more often?

[stj]

Re: LED modifications that have a warning...why?

if you have a switching psu with a single diode and you swap it for a bridge rectifier you increase efficiency but alter the Pf

changing the cap value in a dropper to effect brightness can also change the Pf from the original spec.

[eccerr0r]

Re: LED modifications that have a warning...why?

if you have a switching psu with a single diode and you swap it for a bridge rectifier you increase efficiency but alter the Pf

That would increase PF

changing the cap value in a dropper to effect brightness can also change the Pf from the original spec.

I don't know how much of one you'll get in todays ultra-optimized designs, and may even need to consider lifetime, some LEDs are cutting corners to get maximum brightness as it is.

I was wondering about two dollar store LEDs that are at 100W equiv (14W) and a 60W equiv (8W). The rated lifetimes of each are 15000h and 25000h respectively. I wonder how much of that 100W equiv bulb was due to overdriving the LEDs to get higher brightness considering the lifetime is lower?

[stj]

Re: LED modifications that have a warning...why?

i wouldnt use led lamps over 6w unless they are the filament-style.
the traditional smd led ones generate too much heat.

[eccerr0r]

Re: LED modifications that have a warning...why?

not sure it matters, conduction into the metal plate and then radiation, vs direct radiation into air/freespace... tough to call which is better as both would need to dissipate the same amount of heat. Personally, if I can feel the heat on the outside of the bulb, it's heat that's not stuck inside the bulb.

I think the filament style seems more for the nostalgia, people like seeing the filaments, reminds them of old fashioned bulbs that didn't wind the tungsten into a small spiral because the technology wasn't available. Me, I don't stare at light bulbs, same reason why I don't stare at the sun...

[stj]

Re: LED modifications that have a warning...why?

no, the filament style generate less heat because they use dozens of series leds and almost reach line voltage so they need hardly electronics.

i'v run several filament lights and then unpugged them and felt the base to compare against the other type.
the filament ones just ran warm - the others got the base too hot to hold.,

[eccerr0r]

Re: LED modifications that have a warning...why?

It would depend on what kind of chips they have, but I'd imagine to keep the price down they would have to use run of the mill chips and for the same amount of light they'd have to dump the same amount of heat.