PDA

View Full Version : super nerd lighting question



darpin
05-09-2005, 05:30 AM
Hello folks.

I'm trying to grow my first batch right now, and as such am asking all kinds of questions. I work as an electrical engineer, mainly in the broadcast realm.

There's this common problem with broadcast, where in order to double your power output, you need to consume the square of your original power. For example:

To double the output of 100W, (100 x 100), you need 10,000 watts.

To double the output of 10W, (10 x 10), you need 100 watts.

Just curious if lighting obeys the same laws, but I wouldn't see why not. The spectrum I'm used to dealing with is VHF, but there are more commonalities than differences as you move up and down the spectrum, so the generation of visible light, ultra red, and ultra blue should behave much the same way.

If this is the case, it would explain why someone might get decent performance with a 100W HPS bulb, and need to go to 1000W to really notice a difference, and even at then, you're only maybe 30% better (math is off).

Thoughts, theories?

snow owl
06-21-2005, 03:44 PM
its all about the equal coverage of lumens more than the watts. In veg, plants require less lumens than when flowering. Depending on the size of the space you are dedicating to garden, use 250w metal halide (blue spectrum) in a closet or a 400w MH for every 4sq'. When flowering 600w high pressure sodium(red spectrum) are hands down the most efficient lumen/watt light on the market. ie. 1000w creates 115,000 lumens vs. 600w creates 90,000 lumens. Thats 115 lumens per watt vs. 150 lumens/watt. With the expoential loss of lumens every foot the light is distanced from the plants, 600w can be placed closer than 1000w and ultimately supply more lumens cheaper and with less heat especially using a light mover can get you even closer. 600w cover approx 5sq'.

Beeblebrox.420
06-21-2005, 06:56 PM
There's this common problem with broadcast, where in order to double your power output, you need to consume the square of your original power.
Just to be clear, so that those who have some knowledge of this subject don't wind up scratching their heads, this is a rule of thumb which refers to the doubling of the received power by squaring the transmitter output (at least this is what I am 90% certain you are referring to). This is the so-called inverse-square law. This law only applies accurately to a point-source isotropic radiator - that is, one which transmits equally in all directions, and appears pointlike from the point of view of the receiver. This doesn't scale well to grow lighting which is neither isotropic nor pointlike. With suitable reflectors, doubling input power approximates a doubling of received power.

Zandor
06-21-2005, 07:52 PM
Your math does not work out try again. Careful there are 2 of us on this board who are real electrical engineer. I for one worked in the communication field for 20-years before starting my own company full time 8 years ago. Power is log rhythmic to the power of 10 so itâ??s not 10*10 like you are saying. Look it up again and rephrase your question I think you just miss spoke.

I bet you never thought you would find 2 electrical engineer on this type of forum?â?¦..lol

harmonicminor
06-22-2005, 01:11 AM
and dont forget the flux capacitor and E=m c squared :-)

HARDDON
06-22-2005, 03:25 AM
and dont forget the flux capacitor and E=m c squared :-)

Look if you just add a secondary altimeter and some mirrors, all lighting issues are null :)

Da1KrayzieThug
06-22-2005, 05:45 AM
ROFLHAHHAHA fuckin funny ass people.