[time-nuts] 100 watt higher LED power supply...
Time-Nutters-- OK-- So flicker would be objectionable running off a rectified 110VAC line.My thinking was to find a way around needing a current limiter that would waste energy as heat. Rectifying (and some filtering) of the 110AC line seemed to be one approach. I am thinking of building a several hundred watt LED light for over my workbench by mounting the LEDs on an existing frame for a 4-lamp (long-tube) fluorescent lamp fixture and using the large surface area of the metal frame as a heat sink. The 100 watt LEDS are on eBay but I have not seen the current-limiting drivers for them on eBay. Mike Baker ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 100 watt higher LED power supply...
Boy I have been staying clear of this discussion. Pretty sure they make drop in led tubes now at $$$ Its funny we speak to a 100 watt lamp. But for a led that would be something like 24 watts. It makes no sense to speak in watts. Instead Lumens. I think we want the luminisity of a 100 watt incandescent bulb. Was in a hotel elevator last week that had replaced the overhead lamps with 4 chip LEDs. Both the intensity and color were very impressive. I was thinking great for the bench. Wanted to unscrew one and see who made them. It was the small form factor like Halogen. Regards Paul WB8TSL On Tue, Sep 18, 2012 at 8:56 AM, Michael Baker mp...@clanbaker.org wrote: Time-Nutters-- OK-- So flicker would be objectionable running off a rectified 110VAC line.My thinking was to find a way around needing a current limiter that would waste energy as heat. Rectifying (and some filtering) of the 110AC line seemed to be one approach. I am thinking of building a several hundred watt LED light for over my workbench by mounting the LEDs on an existing frame for a 4-lamp (long-tube) fluorescent lamp fixture and using the large surface area of the metal frame as a heat sink. The 100 watt LEDS are on eBay but I have not seen the current-limiting drivers for them on eBay. Mike Baker __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 100 watt higher LED power supply...
Hi Paul; I started thinking about this project because we are installing a new EMC room at work and thought we could use totally eliminate lighting as a noise source with LED lighting. Allowing lighting during even the most precise measurements. While researching I ran across some amazing items on eBay out of China. I was talking about these raw chip arrays in which a 100watts means it consumes 100watts like 400-800watt in conventional incandescent light. The LED's are also more directional so in a number of applications the seem Lumen output may produce more LUX where needed. Light Temp is another big deal. In all these products their claimed ratings and actual ratings can very different. I prefer actual wattage since it seems the most accurate rating, but it took some time to understand the different efficiencies between product type. I will most likely go with a larger number of lower wattage arrays, and mix and match color temp to taste. My ultimate goal is to greatly improve my current lighting to make up for my aging eyes while at the same time lower lab noise. I also hope the increased efficiency will help with temperature stability around the lab while saving energy. Last, I was hoping to do it for about the price of replacement bulbs in my current lighting. Thomas Knox Date: Tue, 18 Sep 2012 09:47:23 -0400 From: paulsw...@gmail.com To: time-nuts@febo.com Subject: Re: [time-nuts] 100 watt higher LED power supply... Boy I have been staying clear of this discussion. Pretty sure they make drop in led tubes now at $$$ Its funny we speak to a 100 watt lamp. But for a led that would be something like 24 watts. It makes no sense to speak in watts. Instead Lumens. I think we want the luminisity of a 100 watt incandescent bulb. Was in a hotel elevator last week that had replaced the overhead lamps with 4 chip LEDs. Both the intensity and color were very impressive. I was thinking great for the bench. Wanted to unscrew one and see who made them. It was the small form factor like Halogen. Regards Paul WB8TSL On Tue, Sep 18, 2012 at 8:56 AM, Michael Baker mp...@clanbaker.org wrote: Time-Nutters-- OK-- So flicker would be objectionable running off a rectified 110VAC line.My thinking was to find a way around needing a current limiter that would waste energy as heat. Rectifying (and some filtering) of the 110AC line seemed to be one approach. I am thinking of building a several hundred watt LED light for over my workbench by mounting the LEDs on an existing frame for a 4-lamp (long-tube) fluorescent lamp fixture and using the large surface area of the metal frame as a heat sink. The 100 watt LEDS are on eBay but I have not seen the current-limiting drivers for them on eBay. Mike Baker __**_ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/** mailman/listinfo/time-nutshttps://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 100 watt higher LED power supply...
On Tue, Sep 18, 2012 at 5:56 AM, Michael Baker mp...@clanbaker.org wrote: Time-Nutters-- OK-- So flicker would be objectionable running off a rectified 110VAC line.My thinking was to find a way around needing a current limiter that would waste energy as heat. Even if flicker were not a problem what happens if the AC line voltage goes up? How to prevent over driving the LEDS. Or a voltage spike on the AC mains. I think you ned some kind of line regulation. Andin a 100W system you will have heat. The LED's current draw depends on temperature so you'd need some load regulation too. Or another way around the need for regulation is to run the LEDS at reduced power so there is a large safety margin for heat and line voltage variation. But then you need more LEDs for the same amount of light. A constant current DC power supply is not that hard nor expensive but if LEDs are cheap enough just get 2X more of then and run them at 1/2 rated current. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 100 watt higher LED power supply...
Hi A LED is indeed a diode. It's current changes pretty fast as voltage changes. It's voltage drop also highly temperature dependant. Driving one with a constant voltage and no current limiting is a very tough proposition. You would need to feedback the temperature of the device and adjust the supply accordingly. It's much easier to do this some sort of current feedback. Compared to raw rectified AC, current regulation will also keep you from blowing out the entire array when there's a spike on the supply line. Bob -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Tuesday, September 18, 2012 11:45 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] 100 watt higher LED power supply... On Tue, Sep 18, 2012 at 5:56 AM, Michael Baker mp...@clanbaker.org wrote: Time-Nutters-- OK-- So flicker would be objectionable running off a rectified 110VAC line.My thinking was to find a way around needing a current limiter that would waste energy as heat. Even if flicker were not a problem what happens if the AC line voltage goes up? How to prevent over driving the LEDS. Or a voltage spike on the AC mains. I think you ned some kind of line regulation. Andin a 100W system you will have heat. The LED's current draw depends on temperature so you'd need some load regulation too. Or another way around the need for regulation is to run the LEDS at reduced power so there is a large safety margin for heat and line voltage variation. But then you need more LEDs for the same amount of light. A constant current DC power supply is not that hard nor expensive but if LEDs are cheap enough just get 2X more of then and run them at 1/2 rated current. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 100 watt higher LED power supply...
You really want to drive the LEDs with switcher designs typical in battery chargers, basically hysteretic current output. Prior to LIon batteries (which are voltage sensitive), the old nicad/NiMH chargers used the hysteretic scheme. If you want a simpler switcher, you can take the garden variety voltage regulated switcher and hack it to be current regulated. LTC and Micrel sell chips for exactly that use. Note that the really bright LEDs are designed for a 10 year life at those power levels. (Sadly, true for LED backlit TVs.) I was at a trade show where CREE had a display. For natural lighthing, they mix some red LEDs in with the white LEDs. Uh, the dope growing LED fixtures do the same thing. ;-) ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
