DuB BoY

I was reading and came accross this link. http://www.growrooms.com/ballast/ it is a DIy HID light instrucions. I was wondering what makes a switchable ballast a switchable ballast. From reading the diagram it looks to me the only difference between HPS and MH is the ignitor. I have a HPS ballast and was wondering if I make a switch to turn off the ignitor would I be able to use a MH bulb?

Thanks

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DuB BoY

sparkyrudy

I am in electronics and that sounds totally feasible to me. You may need to check power ratings to be sure the switch will handle the surge you have with high wattage devices. Haven't tried myself but I am planning to experiment in this same area myself - real soon. I'll let y'all know!

Good Luck on Your Grow Project!

Sparky

DuB BoY

Cool let me know if you come up with anything.. Is there anyone out there that has a switchable ballast that can look and see what the switch does?

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VBgoku

this is one subject we need to dig deeper ont because i have this same problem. i have a light system that i bought for $50 and it has everything in it except for the plug and the bulb. but the prob is that i don't know what kind of bulb it was ...it looks like it's a MH but it could also be a switchable hps. haven't taken it aprt yet but i've got it gor 2 weeks already. i can't really take things apart and put hem back together unless i know what i'm doing.

1 how do you put plugs into the wires?
2 how do you know the wattages of your system?
3 can you buy high wattage bulbs at home d or menard or Ace?

sorry for bombarding your page dub.. if you don't want all this ??'s here just ask the mods to remove it.

Ocelaris

Excellent thread, I would love to know the answer to these questions. Though putting together a dual 400w MH and HPS system yesterday, the Open voltages of Metal Halides and High Pressure Sodium seem to be different? I would check out the spects at venture, magnetek, or advance, their spec sheets.

My guess is that you can run a MH light on a HPS ballast WITHOUT the ignitor, but that you won't be able to run a HPS light on a MH ballast with the ignitor...

Has anyone considered the new Pulse Metal Halide ballasts? like the 320w varieties that put out the same lumens as a regular strobe start 400w MH? I believe the only difference is that they have an ignitor, but I could be wrong.

VBgoku,
I am assuming you are american, or canadian (I dunno if canadians use the same 120/60 that we do in america?) But my advice does not apply to european electricity.... to continue

1) you need to buy a 120v 60hz plug at home depot. the plug should be self explanatory.
2) look at your ballast, it will have all the information you need.
3) you can buy 400w MH, HPS, 250w HPS, MH etc... at most local hardware stores, I would not reccomend the cheap MH bulbs as to me they are not a complete source of light, Try a higher color temperature MH bulb, the daylight or aquarium ones.

PM me if you have any other questions, let's keep this thread clean.

DuB BoY

Well I went to Universal lighting and pulled up the specs for a 1000 Watt MH and HPS ballast. It seems they are a little different but not much. Like I said I am no electrician so I hope some of you can interput this better than I. Here are the differences I found.

HPS MH
Recommended Fuse 8 10
Capacitor Value 26 MF 24 MF
Capacitor Volt rating 525 Volts 480 Volts


Electrical Characteristics For HPS
Line current in AMPS Operating 2.40 Open 1.50 Start 1.30
Input Watts 1100 Open Circuit volts 440 Drop Out Volts 360


Electrical Characteristics For MH
Line current in AMPS Operating 2.30 Open 1.60 Start 1.50
Input Watts 1080 Open Circuit volts 420 Drop Out Volts 320

There are also some minor physical characteristics that differ also but didn't seem to important to me.

Here are the spec sheets that I based this info from.. You need acrobat reader to view.

HPS Specification Sheet

MH Specification Sheet

Lets keep it going...

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My Grow Journal Lifesaver Clones

One of the advantages of being disorderly is that one is constantly making exciting discoveries....
DuB BoY

Ocelaris

I forget if I mentioned it, but the HPS ballasts seem to be heavier and larger per same wattage... and I think the open wattage is the key there, that the HPS's will run a final higher open voltage, but I'm not sure if that really is what keeps the ballast going... Like line tolerance? Not sure it would be economical to buy a line regulator of that size just to be able to run a stable current... My thinking is that the larger coil on a HPS, runs a final higher open voltage. Here's some research at venture I did... will do more later, but thought it was interesting. The S52 is 1000w HPS, M141 is the new Pulse start (read ignitor) 1000w MH, and M47 is 1000w Metal halide... I just did 1000w because Dub Boy did... And I reccomend that we go down to the 400w range, because I believe there is some signifcant variety when you get upto the 1000w range, where as I thought 400w MH and MV were very similar. Like I remember reading somewhere that 1000w was the threshold at which you start to get funky because it's such high wattage, maybe 400w would be a better reference. I probably will go down to look at 400wers... But Here's my 1000w help, probably reiterating the same thing as Dub boy... I like this thread. Ocelaris

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Ocelaris

Damn that was swift of me, anyone else catch that english eloquence in my first post :-)

Lemme add a nice linky to make up for that...

http://www.gaash.com/html/articles.htm

Just a little article on pulse start vs. Strobe Start. And I think the difference is getting the arc started with a HPS vs. a MH... like I wish I knew the physics behind the ignitor, I realize the capacitor is for regulating open voltage, but what's the ignitor do? I mean is it just like a secondary capacitor that throws a high voltage to get the arc started? I think this hobby is getting to the point where a textbook would be appropriate :-) always nice to get to that point.

PotsimusMaximus

Those "small" differences are fairly significant. There is a good HID lighting FAQ online but I dont have the link. A google search should do it.

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JoseHempSeed

yes, the ignitor produces the initial high-voltage pulse to start the glow discharge...

the ballasts seem fairly identical except for the ignitor in the circuit. it looks like the voltage/current/cap specs would all be reasonable close - at least within the parts' tolerances - so i would think YES they can be swapped by just switching the ignitor in and out of the curcuit.

i'd sure like a peek inside one of those switchable ballasts

a while back there was a post where someone said they actually did this...and it worked fine. but i can't find that post anymore...

anyway here's a neat pic i got off the advance transformer site...

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