The Lumatek challenge! - Page 2

Al B. Fuct · #11 06-01-2007, 12:44 PM

nice heat sink.

abudsmoker · #12 06-01-2007, 12:47 PM

Well have no fear, we will test the hell outta this thing and get all the answers you need, i opened a $1000.00 budget to test this light out. i will be using a soilless mixture at simulate the airration you get in hydro. and have the other half in Foxfarm X Abuds amendments. i will set up this tray and we are going to have even more eye candy.

i will give you ballast temps monday or tuesday

abudsmoker · #13 06-01-2007, 12:48 PM

they look so big here, i hope the buds come out this big

Al B. Fuct · #14 06-01-2007, 12:56 PM

My question can be answered in 10 mins- doesn't matter what else is happening in the op.

All I want to see is the light meter measurement from one particular HPS tube, when it is run on one ballast and then run on the other.

Al B. Fuct · #15 06-01-2007, 01:09 PM

Just to be clear- and I said this in another recent thread about digital ballasts- I DO like the things. They do save a little power managing the current to the HPS tube ('bout 50W less than a comparable magnetic type) and will extend the number of starts in each HPS tube lifetime. I'm just sceptical of Lumitek's greater luminous output claim.

Is your new ballast a 400 or a 600?

babygro · #16 06-01-2007, 02:44 PM

Quote:

Originally Posted by Al B. Fuct

Digital ballasts do 'soften' the startup, but the HPS tube dissipates the same number of watts whether driven by a magnetic or digital ballast.

There's no electrical way an HPS tube will make any more light unless more current is being dropped across the arc tube. Increasing the current across the tube (by increasing voltage applied) would also increase the heat dissipation and shorten the life of the electrodes in the arc envelope.

Come Al B you're not thinking mate.

I've seen you say pretty much the same thing several times now "There's no electrical way an HPS tube will make any more light unless more current is being dropped across the arc tube." Yes there is, you're just not aware of it, AND you're making a horrible assumption here which is why you're going wrong. You're 'assuming' the Magnetic Core and Coil ballast sends exactly 600w's of electricity to the lamp - they don't, even though they consume that much electricity.

How can the Magnetic ballast 'consume' the 'right' amount of electricity yet still not produce 600w as lumens or light? Power factor. The power factor of Magnetic Coil Ballasts is pretty low and gets lower as the ballast ages. That's why over time Magnetic ballasts consume MORE electricity and put out LESS lumens.

Magnetic coil 'inductive' loading ballasts typically have a power factor of 0.4 - 0.6 (the perfect power factor is 1.0) Electronic Ballasts typically have a power factor of 0.9 - 0.95, which bascially means they're a lot more efficient and effective in the way that they convert electricity into lumens at the bulb, and Magnetic Coil ballasts waste a lot of electricity in doing the same conversion and therefore cannot send 600w of electricity to the bulb.

This is the reason the Electronic Ballast can output more lumens at the bulb for the same 'supposedly' input current as a Magnetic Coil and Core. So in a way, you're absolutely right, you can't get more lumens at the lamp for a given amount of voltage, current or wattage, but you can get a lot less than 'optimum' for the same given current or voltage if your Magnetic Ballast has a lowish Power Factor, even more so if it's 3+ years old.

Some light recreational reading for you -
Power factor - Wikipedia, the free encyclopedia

abudsmoker · #17 06-01-2007, 02:58 PM

Quote:

Originally Posted by Al B. Fuct

Just to be clear- and I said this in another recent thread about digital ballasts- I DO like the things. They do save a little power managing the current to the HPS tube ('bout 50W less than a comparable magnetic type) and will extend the number of starts in each HPS tube lifetime. I'm just sceptical of Lumitek's greater luminous output claim.

Is your new ballast a 400 or a 600?

i went with the 600 as we were talking about the 600 being almost as good as my conventional mag ballasts

abudsmoker · #18 06-01-2007, 03:01 PM

I hope we settle these questions and i hope this will help convert more of you to the digital ballasts, they definatly give you more bang for the buck!

babygro · #19 06-01-2007, 03:18 PM

Quote:

Originally Posted by abudsmoker

I hope we settle these questions and i hope this will help convert more of you to the digital ballasts, they definatly give you more bang for the buck!

I'm already converted and intend on investing in a 250w version fairly shortly.

The 'quantifiable' reasons are enough for me alone, the lower ballast heat output, the lower overall running costs, the ability to seamlessly switch between MH and HPS bulbs and the lengthened bulb life.

I doubt very much whether it produces 30% more lumens than an equivalent Magnetic coil ballast, I think that is a somewhat optimistic estimate, 5-10% is probably far more likely.

The high (relatively) running costs of Magnetic coil ballasts is whats always put me off them, add into that the huge amounts of lumens HID's put out that are simply not used by the plants - that you're paying for, and higher wattage CFL fluorescents and even T5HO PURple strip electronic fluorescents with their higher PAR outputs and lower running costs offer (in my opinion) far more 'value for money' than HIDs at the lower end of indoor growing.

This isn't an attempt to re-ignite the HID v CFL/T5 Fluro debate either, that happens to be my opinion and as such I'm perfectly entitled to express it - it's what I beleive. Those people running 1000w systems who get good results from them, if you're willing to pay the higher running costs of those sysems in exchange for better results - good for you. I don't have a problem with that at all, your money, your results, your choice, each to their own. Personally, I think 1000w systems are the most inefficient and cost ineffective of any indoor plant lighting system - but that's just me.

Al B. Fuct · #20 06-01-2007, 05:44 PM

Quote:

Originally Posted by babygro

I've seen you say pretty much the same thing several times now "There's no electrical way an HPS tube will make any more light unless more current is being dropped across the arc tube." Yes there is, you're just not aware of it,

Really? Did you ask Mr Ohm before adding letters to I2R?

Which ones did you add?

Quote:

AND you're making a horrible assumption here which is why you're going wrong. You're 'assuming' the Magnetic Core and Coil ballast sends exactly 600w's of electricity to the lamp - they don't, even though they consume that much electricity.

Dude, you obviously don't know how HPS tubes work. Don't worry- I can help.

That funky little tube that glows has a small amount of liquid mercury-sodium amalgam which is vapourised by a 2.5-4kV pulse controlled by the ignitor. Once vapourised in the tube, the amalgam is conductive at lower voltages and an arc path is formed. However, as the temperature of the amalgam increases, its resistance decreases. A ballast is simply a current limiter to prevent the tube from melting due to thermal runaway.

The tube is designed to handle a certain amount of power. The control gear is designed to restrict current to the limits of the tube. The power consumption of the tube is determined by the amount of current (I) sunk across the resistance (R) of the amalgam in the lamp tube.

Quote:

How can the Magnetic ballast 'consume' the 'right' amount of electricity yet still not produce 600w as lumens or light? Power factor. The power factor of Magnetic Coil Ballasts is pretty low and gets lower as the ballast ages. That's why over time Magnetic ballasts consume MORE electricity and put out LESS lumens.

Who says a 600W HPS tube connected to a magnetic ballast doesn't consume 600W? Got news for you- they DO consume within 5% of 600W if the tube is running in free airspace.

If the tube is in a luminaire, the temperature of the tube will increase and its resistance will decrease. Since a magnetic ballast won't compensate for the lower resistance and is in series with the lamp tube, the voltage dropped across the tube will increase, by as much as 12V under acceptable tube temperature ranges.

The power factor is corrected by a capacitor.

Magnetic ballasts do consume a small amount more (9%, didn't we figure?) power than digitals owing to eddy-current losses their iron-cored inductors, but they still deliver power to the lamp tube at the tube's design spec, limiting current based on the reactance of the inductor.