RFI from Cree LED bulbs?

[k0ua]

We have two lamps in our bedroom that have no switches. Each had two 40 watt candelabra base bulbs. And after 14-15 years, one bulb finally burned out. With no switch, you touch a lamp anywhere on it and it comes on, touch it again and it brightens, a third time brightens more, and a fourth touch turns it off. With this type 3-way, I was sure I didn't want 3-way bulbs and wasn't sure whether dimmable LEDs would work. But today I stopped by Home Depot again and bought four 40 watt dimmable bulbs (high priced suckers at $10.97 each plus tax, but they work just fine in these lamps.

So now that's 53 LED light bulbs and I think that's every bulb in the house except the 2 refrigerators, microwave, and range oven lights, and one plant light. And of course we have nine 4 foot, two tube florescent lights, one four foot three tube florescent light, two 8 foot two tube florescent lights, and still have the two incandescent bulbs in the Liftmaster garage door opener.

So are you gonna keep track of the last years utility bills, and get some idea on how much you are saving and the payback period for the expenditure?

 

[bumperm]

We have two lamps in our bedroom that have no switches. Each had two 40 watt candelabra base bulbs. And after 14-15 years, one bulb finally burned out. With no switch, you touch a lamp anywhere on it and it comes on, touch it again and it brightens, a third time brightens more, and a fourth touch turns it off. With this type 3-way, I was sure I didn't want 3-way bulbs and wasn't sure whether dimmable LEDs would work. But today I stopped by Home Depot again and bought four 40 watt dimmable bulbs (high priced suckers at $10.97 each plus tax, but they work just fine in these lamps.

So now that's 53 LED light bulbs and I think that's every bulb in the house except the 2 refrigerators, microwave, and range oven lights, and one plant light. And of course we have nine 4 foot, two tube florescent lights, one four foot three tube florescent light, two 8 foot two tube florescent lights, and still have the two incandescent bulbs in the Liftmaster garage door opener.

You were right on!

"3-way" incandescent bulbs have two filaments, one brighter, higher wattage, than the other, and an additional contact on the base. Low is the smaller filament on, Medium is the larger filament, and High will have both filaments powered. This type of bulb will usually have a mechanical switch to select brightness.

By nature, incandescent bulbs are dimmable by varying the voltage and thus the power they consume. With the advent of solid state electronics, dimmers became more efficient and less expensive, so those old 3-way bulbs sort of went out of vogue.

For a LED bulb to work with a dimmer, the driver circuit (in the base of the bulb) has to be designed such - so the dimmable LED bulb with normally say so on the package, and cost a bit more.

 

[Bird]

So are you gonna keep track of the last years utility bills, and get some idea on how much you are saving and the payback period for the expenditure?

I already keep a spreadsheet showing the KWH used, total bill amount, and total cost per KWH each month, so yes, I'll have some idea. Of course this is a total electric house, so the heating and cooling are the major costs and since that spreadsheet doesn't include the temperatures, it will only be an estimate.

 

[Bird]

so the dimmable LED bulb with normally say so on the package, and cost a bit more.

Yep, and a number of my other LED bulbs are "dimmable" although this is the only place that feature is used. I knew the dimmable bulbs cost more, but sometimes I couldn't find what I wanted that was not dimmable.

 

[MossRoad]

We have two lamps in our bedroom that have no switches. Each had two 40 watt candelabra base bulbs. And after 14-15 years, one bulb finally burned out. With no switch, you touch a lamp anywhere on it and it comes on, touch it again and it brightens, a third time brightens more, and a fourth touch turns it off. With this type 3-way, I was sure I didn't want 3-way bulbs and wasn't sure whether dimmable LEDs would work. But today I stopped by Home Depot again and bought four 40 watt dimmable bulbs (high priced suckers at $10.97 each plus tax, but they work just fine in these lamps.

So now that's 53 LED light bulbs and I think that's every bulb in the house except the 2 refrigerators, microwave, and range oven lights, and one plant light. And of course we have nine 4 foot, two tube florescent lights, one four foot three tube florescent light, two 8 foot two tube florescent lights, and still have the two incandescent bulbs in the Liftmaster garage door opener.

I'm sure (from our conversations in the past) that you're keeping track of your electric use. Please let us know if you see any significant drop. Thanks. :thumbsup:

 

[SPYDERLK]

That would be a head scratcher..I would really wonder how the LED dome light would cause much if any RFI. But stranger things have happened. I would think since the automotive power supply is DC to begin with and a simple dropping resister would work for getting the voltage down to safe levels for the LED lamp, that would be how the manufacture would have made it.. But perhaps not. Perhaps there was some other form of electronic regulator in the LED that caused the RFI. I often wonder where some Electrical Engineers got their educations. Perhaps from a box of cracker jacks? Understanding and using Radio Frequency energy is a part, or at least it was of the EE program back in the day. I did not finish the EE program, and I am not a EE, but I have some sense of these things. As Forrest Gump would say "I am not a smart man, but I know what love is".

They must have been going for greater efficiency by using a switching regulator to control LED current. Unfortunately the switching frequency was radiating enuf to affect the car computer as it received signals from the remote. Lower emission or better signal discrimination, or both, is needed.
larry

 

[ultrarunner]

How about this bulb for a "long timer"

Centennial Light - Wikipedia, the free encyclopedia

Livermore's Centennial Light Facts

That bulb is a local superstar... no one wants it to go out on their watch...

When the fire house moved the bulb has it's own VIP escort...

As far as long lasting... years ago I bought a pack of bulb life extenders... little disks that went into the base for the bulb socket... all I can say is boy do they work... more than 20 years and have not changed a single outdoor flood... and they are on motion sensors... so one and off.

 

[ultrarunner]

Has anyone tested/evaluated the new CREE LED replacement bulbs?

They are the next generation of the original that came out about two years ago and do not cost as much.

Just wondering if the lower price means something was compromised.

 

[bumperm]

That bulb is a local superstar... no one wants it to go out on their watch...

When the fire house moved the bulb has it's own VIP escort...

As far as long lasting... years ago I bought a pack of bulb life extenders... little disks that went into the base for the bulb socket... all I can say is boy do they work... more than 20 years and have not changed a single outdoor flood... and they are on motion sensors... so one and off.

No magic there, those life extenders are simply resistors. They drop the voltage so as to run the bulb below it's rated voltage and current. This makes it last a lot longer. But, and it's a big BUT, the bulb running on less power puts out less light. Further, there's voltage dropped across the life extender and that wastes power as you get nothing for that electricity except heat - oh, and the bulb lasts longer.

LEDs really are the way to go. Even with electricity at todays dollars, assuming the cost of power doesn't increase, the LEDs will still pay for themselves. LEDs will often put out more light if that's what you want. If you don't need more light, then LEDs will save money in using less power and lasting much longer than other options.

 

[ultrarunner]

No magic there, those life extenders are simply resistors. They drop the voltage so as to run the bulb below it's rated voltage and current. This makes it last a lot longer. But, and it's a big BUT, the bulb running on less power puts out less light. Further, there's voltage dropped across the life extender and that wastes power as you get nothing for that electricity except heat - oh, and the bulb lasts longer.

LEDs really are the way to go. Even with electricity at todays dollars, assuming the cost of power doesn't increase, the LEDs will still pay for themselves. LEDs will often put out more light if that's what you want. If you don't need more light, then LEDs will save money in using less power and lasting much longer than other options.

Those two floods are in a very awkward place to climb up and get too... having the floods last decades has been a huge benefit for me... the official bulb changer in the family...

As for my own and Mom's place... just about all CREE bulbs going on 2 years now... very pleased is an understatement.

I have oodles of can lights in Olympia and the home has 5 bedrooms... electricity is the only utility bill and it can get quite high in winter...

It would cost a lot to replace all the bulbs to LED... I guess I would also need more heat to compensate for the cool running LED in place of conventional floods... Olympia tends to get cold for extended periods of time each year... and is seldom really hot... maybe one week a year...

LED bulbs are an example of when technology and utility come together...