RFI from Cree LED bulbs?

[dragoneggs]

I have used CREE LEDs in an array for Reef Aquarium lighting for several years with 'on' time about 10hrs per day everyday. Haven't had one bulb go bad yet out of a few hundred. It is always a circuit board or power supply that gives up. I'm impressed with the efficiency, low heat output at high lumens, and how I can dial in color temp by using red white and blues.

 

[nova3930]

I just use the light switch, like I was taught as a kid. An amazing energy saving device that is just about 100% already installed just ahead of all lightbulbs.:wink:

I do too but trying to get the wife to go along is a lost cause. My boy isn't old enough for light switches but I expect he'll be the same. I play a game to see how many lights I have to turn off before I leave the house in the morning. My record is near 20. Sometimes I think my entire purpose as a husband/father is to make sure light switches works in the other position.

 

[MossRoad]

When I was a kid my mom would walk into a room, turn the lights on, then walk out. My dad would walk in, turn the lights off, then walk out. It would go on all evening. We kids just sat there and watched.... :laughing:

 

[k0ua]

When I was a kid my mom would walk into a room, turn the lights on, then walk out. My dad would walk in, turn the lights off, then walk out. It would go on all evening. We kids just sat there and watched.... :laughing:

Sounds like my wife and I. Shhhh.. Don't tell anyone I said that!

 

[MossRoad]

DAD? Is that you?

:laughing:

 

[Sysop]

When I was a kid, I always got told to turn the lights on and even heard "are you really using every light in the house all at once right now?" a couple times...

Now that I am the age my parents were at the time, I find myself saying the same things to my kids... The kids think it is especially funny now because my father is always leaving lights on these days too. He walks into rooms, well lit from daylight coming in the windows, and will still turn on the light, leave the room, and leave it on for hours...

I think it is a cycle and we eventually come full circle...

 

[k0ua]

I just got done testing a Cree "4flow" LED 40 watt bulb for RF interference. I could not find any from 200Khz to 59Mhz. Now I did not check every frequency in that range, but I do have a spectrum monitor on the receiver and did not see or hear anything. This is the new Cree design without the heat sink, that has little slits in the plastic "bulb" that allow for a chimney effect of cooling air to flow through the bulb. I was a little worried that without the shielding effect of the metal heat sink these might be dirtier than the othe Cree's but that does not seem to be the case. So far so Good on the Cree Brand. I am starting to get on this LED bandwagon. CFL's I think were just a stopgap measure. We shall see how reliable and long lasting these "newfangled" bulbs are, but if they will do what they say, then yes, by all means they will save me some money in the long run. Not to mention the ability to run them at least for a short time from my UPS's. And the reduction of unwanted heat in the summer will be great.. Not so great in the winter. Also one other downside, my cat liked to park directly under the lamp on my table to sleep, and now she doesn't seem to care to do that. Not enough warmth to interest her! Sorry kitty!:cat:

Cree Model # BA19-04527OMF-12DE26-3U100 Internet # 205597080 Store SKU # 1001085533

 

[Sodo]

James that's interesting & thanks for getting this thread back on topic.

I saw a thread on a forum where a guy raised holy h*** with his auto dealer because the remote on his new car (with warranty) was not reliable. It would work once then not afterwards. In the end of the thread they said they determined that at first press the domelight turned on, (owner-installed aftermarket CREE domelight) causing RF interference that the key FOB could not always compete with. Removed the CREE domelight and the remote worked reliably again.

I've been wondering if it was a useful diagnosis.

 

[k0ua]

James that's interesting. I saw a thread on a forum where a guy raised holy h*** with his auto dealer because the remote on his new car (with warranty) was not reliable. It would work once then not afterwards. In the end of the thread they said they determined that at first press the domelight turned on, (aftermarket CREE domelight) causing RF interference that the key FOB could not always compete with. Removed the CREE domelight and the remote worked reliably again.

I've been wondering if it was a useful diagnosis.

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".

 

[Sodo]

Yep could have been some other problem, which solved itself in the same timeframe.

One could argue that EEs who design a product that gets to market FIRST without the R&D phase bankrupting the project have smarts too.