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Re: >Subject: Re: First post: Fluoresce



At 04:25 AM 10/21/96 +0000, you wrote:
>> Subject: Re: >Subject: Re: First post: Fluoresce
>> >>Subject: Re: First post: Fluoresce
>
>From pgantt-at-ix-dot-netcom-dot-comSun Oct 20 22:10:33 1996
>Date: Sun, 20 Oct 1996 13:13:00 -0700
>From: pgantt <pgantt-at-ix-dot-netcom-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: >Subject: Re: First post: Fluoresce
>
>Tesla List wrote:
>> 
>> >From couturejh-at-worldnet.att-dot-netFri Oct 18 21:54:09 1996
>> Date: Fri, 18 Oct 1996 08:20:48 +0000
>> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>> To: tesla-at-pupman-dot-com
>> Subject: Re: >Subject: Re: First post: Fluoresce
>> 
>>  Big snip
>> >
>> 
>> Keep in mind that light is radiant energy and must be less than the energy
>> at the input of the Tesla coil or you will have over unity energy. The
>> efficacy of the light is dependent on color, frequency, and bandwidth. The
>> efficacy of white light (wide bandwidth) is about 187 lumens per watt. The
>> lumen is light power. One footcandle is one lumen per square foot. A 40 watt
>> fluorescent lamp is about 100 lumens per watt.
>> Light output energy = Tesla input energy minus losses.
>> 
>> Jack C.
>
>What you say sounds reasonable.  If you consider that in a 60Hz lighting
>system
>only about 2% of the energy produces light, this in very inefficient. 
>The method
>I described has much higher efficiency than that.  Unfortunately,
>however, I did
>not have the instrumentation to make light measurements.  This was the
>next step 
>in the development process.
>
>Phil Gantt
>
>
It is difficult to determine the overall efficiency of a fluorescent lamp
because the light energy output is not distributed evenly over the visible
light spectrum. However, the standard ballast uses about 10 watts for a 40
watt lamp or 100 lumens * 40/50 = 80 lumens per watt. This would make the
overall efficiency = 80/187 = .427 or about 42.7%. This is only partially
correct because the 187 lumens per watt is for a light source that is only
roughly equivalent to a fluorescent lamp. Another complication is that the
ballast is low power factor unless corrected with LPF capacitors.

I have never seen anything published on finding the overall efficiency of a
Tesla coil lighting system. However, I believe you would have the following
situation. Assuming the Tesla coil was to energize a standard fluorescent
lamp the total lumens output would be 40 * 100 = 4000 lumens. At 100%
efficiency you would need 4000/187 = 21.4 watts input not counting the Tesla
coil and other losses. Anything less than this would be over unity energy.
For enample, the standard fluorescent lamp requires about 50 watts. The
Tesla coil lighting would have to be between 21.4 and 50 watts to be better
than the standard fluorescent lamp and ballast system.

This is not a very accurate way to evaluate a Tesla coil lighting system but
will point you in the right direction.

Comments welcomed

Jack C.