What does "pulse start ballast" mean?

[speckled trout]

I found some 175w outdoor MH fixtures that come with a bulb that says use pulse start metal halide lamps on pulse start ballast with sockets that can withstand a 4000 volt pulse.

The bulb they come with produces a bronze colored light and I would want to replace it with a 175w 10,000K one. Will the MH bulbs that are sold in Dr. Foster & Smith work properly or do they require a different ballast?

I'm an idiot when it comes to this stuff, so any help would greatly be appreciated.

[speckled trout]

I read that Ushio's, German Made, and Euro Made bulbs can work, does anyone have experience using a pulse start ballast with one of these bulbs? Are they good or bad when paired up with a pulse start ballast.

Also, the ballast is made by Venture Lighting as will as the fixture.

[outy]

http://www.reefcentral.com/forums/showthread.php?s=&threadid=624185

id start there

[hahnmeister]

http://members.fortunecity.com/paulerik/id39.htm

PaulErik is a regular light guru who you can find on the boards here as well. He is a professional in the field of lighting design, and his page above should fill you in.

In laymans terms, pulse start is the Euro spec, and probe start is the American spec. You can see the diffs in Pauls site, http://members.fortunecity.com/paulerik/id50.htm

But what it really comes down to is that the Euro probe start bulbs/ballasts (HQI happens to be a 'high-grade' version of this) are built better and last longer for use with our reef tanks. This means sticking with double ended or in the case of 400watters, HQI rated bulbs, and pulse start/HQI ballasts.

[speckled trout]

outy,

I've read most of that already. However, as someone completely new to MH's, I'm not fully able to grasp all the jargon used in a lot of those posts.

I'm sure there's a lot of good info in there, but it still leaves a ton of questions to a MH newbie such as myself.

hahnmeister,

My server won't let me view "free host" sites. I love to read what it says, any ideas?

Honestly, my PCs are horrible and I really want to run MHs. Any help would be greatly appreciated.

[hahnmeister]

Well, I cant really copy and paste everything... its alot of info and I dont know exactly what you want. PaulErik is on these boards under that login though... you could PM him.

IF all you wanted was to know pulse start vs. probe start, Ill try to give you the most accurate response I can...

Now, the basic idea behind a halide bulb is that the voltage is increased so that a current can be passed across elements that vaporize in the bulb. These gasses (halides) then give off light like a tungsten filament in a edison bulb, or phosphors in a PC/T5/VHO lamp. But the problem with passing this current through the gas is that the gas needs to be hot to pass the charge... very hot. So there need to be starting mechanisms to get the gas hot enough, or to 'fire up'. For a probe start bulb, the current is passed across a smaller path, usually a smaller electrode positioned right next to one of the two main ones in the bulb. This smaller electrode passes the electricity across a smaller circuit... kind of like a bulb within a bulb, and as the smaller arc/bulb gets warmer, then the main one can take over.

The other method, or probe start, uses bulbs that dont have this extra electrode. Instead, they are higher pressure bulbs. And the ballast has the starting circuitry inside of it this time, not the bulb like with probe start. The ballast sends bursts of energy, I think in a low amp, high voltage manner, until the capacitor in the ballast stops it. Its pretty much handling the issue of starting an arc across the halides by using more power until the bulb fires up.

Thats how they work (I think). There are a few things to take away though that are important. Probe start bulbs are older tech... pulse start is newer. Pulse start bulbs, to get used with their type of ballast, are higher pressure, to pass the higher current for starting, and it pays off in a few other ways as well. Its a bit of a stretch, but phosphor based/tube bulbs are a bit like probe start. There is a starter in the bulbs at one end that passes the starting current until the gas in the bulb is warm enough to pass the current. Thats what the flicker is all about. OR, there are instant start ballasts that do something alot like what a pulse start ballast does... but you get the point. Anyways, this probe, as its starting, spatters, er, it causes some of the phosphors to burn, giving you those black deposits that you see at the ends of old tube bulbs. Well, probe start is a bit like that... the starting mechanism ends up lowering bulb life. Also, these bulbs are lower pressure, so they just dont last as long as the pulse start.

HQI/Pulse start bulbs are also usually double ended bulbs. They can not be started with Probe start ballasts because the ballast doesnt do the whole 'pulse start' thing. OTOH, for obvious reasons, probe start bulbs will run on pulse start ballasts, although the starting is a little more violent than what a probe start is used to. Pulse start ballasts pump more juice to the bulb while running as well compared to probe start. They are simply running at a higher specification.

Probe start ballasts are cheap. They are used in high bay pendants in warehouses. They are the ones that buzz and run hot. The bulbs are designed for vertical, not horizontal operation, and when used in horizontal fixtures, the arc 'bends' with gravity, causing it to come closer to the wall of the inner jacket where the halide gasses end up depositing themselves on the inside of the bulb.

Double ended bulbs are always HQI rated. HQI rated is a 'high quality' spec for pulse start ballasts. Also called M80, its kind of like the elevated standard for halide ballasts, much like THX is to movie theater sound, actually being owned by the OSRAM division of Sylvania Lighting Corp. Single ended bulbs are usually probe start, but there are exceptions. Some 400watt bulbs are in fact HQI spec bulbs... Aqualine 10,000K, Aquaconnect 14,000K, BLVs, etc. They do this because there isnt a 400watt double ended bulb (ok, there is as of 2 years ago, but more on that later).

Single ended bulbs do not require a UV sheild because its built on to the bulb (thats why they are larger bulbs, the sheild is the outer layer). Double ended bulbs, with a couple new exceptions, dont have a UV sheild, and require the use of a UV filtering glass over the bulb. Never remove this glass unless you have to, and never look at the bulb directly without the glass. IF for some reason you do remove the glass (for cleaning or something) while the bulb is on, do not do it while the bulb is starting, as this is when it throws out the most UV...ALOT of UV in comparison to normal running. I have removed it for quick cleanings right after starting however, and no harm has come to the tank's critters, but only for a minute.

Be sure to pair up the right kind of bulb with the right kind of ballast. SE arent going to last as long as DE due to their nature, but if you gotta have one, use an electronic ballast. They are designed to make the bulb last longer by sensing what the ideal current through the bulb is. And while DE bulbs wont start on Probe start ballasts, and pulse start ballasts will start probe start bulbs, a HQI rated ballast will burn a SE bulb out much faster. It might show more output for a month or two, when compared to a regular electronic or probe start ballast, but running that bulb on jet fuel means its death will come that much quicker. Often, running SE bulbs (unless they are HQI rated) on HQI ballasts will result in 60% of the output being lost in one year. Now, a good HQI rated bulb might not start off quite as strong as a SE bulb on a HQI ballast (but more than a SE bulb on an electronic ballast or probe start that its meant to run on), but it will keep its output much longer, often times lasting 2 years with only a 10-20% light decrease. The bottom line is that overdriving or underdriving halide bulbs leads to their early demise, so match em up right.

Bottom line, match what bulbs you want with the right ballast. If you want the higher performing bulb, get the DE/HQI setup.

As for new 400wattDE bulbs... they are not the higher current designs, at least not the ones for the aquarium industry yet. They are probe start bulbs in a DE socket. As a result, they are no better than any mogul based 400watt bulb, in fact, some are rather crappy longevity-wise, only lasting 6 months between changes. And considering you can get Mogul base 400wattHQI bulbs... If HQI is the wolf and probe start is the sheep, its kinda ironic, because in the case with DE 400watters, they dressed the sheep in wolf's clothing. The wolf in sheeps clothing can still kick its butt.

[Gundo5000]

Good infor hahnmeister

[hahnmeister]

Yeah, I left some things out, and if anyone finds any errors, let me know. It was late last night when I wrote it. I know the relation I made between flo bulbs and halides with respect to probe start was a little bit of a stretch, but the concept is right.

I just wanted to add, thanks PaulErik. I would have to attribute at least 1/2 of what I know about halides in the technical aspects to what he has written.

Also, I mentioned underdriving a halide to be just as bad as overdriving it. Overdriving it might be easy to understand, but underdriving it might require some reasoning. Underdriving a bulb means that not all the halide vaporizes inside of the bulb, but rather sits in the bulb, depositing itself and burning into the inside of the bulb on the quartz... meaning it is no longer useful and the bulb's overall output is not only lowered because some of the gasses are no longer available, but the deposits that they create block light from the gasses that are still available.

For this reason, there has been some suspicion among some about using e-ballasts on HQI rated bulbs. Icecap claims that the higher frequency makes up for the lower power needed... higher frequency making up for less power. But I look at it from the other way around. I might add that this is not something PaulErik came up with, but totally me, so if I am wrong, dont ask him why...lol. To me, what matters if the power is right, or the power is being compensated with a higher frequency, is the amount of photons being sent out (aka, the amount of light) by the bulb. Now, you will notice that Icecaps have slightly lower outputs than HQI ballasts give with DE bulbs. If the higher frequency of the e-ballast was truly compensating, then wouldnt the output of the e-ballast run bulb be similar, if not equal to the output of the HQI? And if not, then that means that there are electrons of some of the elements in the bulb that are not elevated high enough to emit photons (light). If they are not elevated enough, or excited enough, by either getting enough power or frequency, then arent they just sitting around, depositing themselves on the glass like an underdriven bulb?

PaulErik is not sure, since there has been no comparative long term testing to compare, but I might add this. I have used identical bulbs in HQI and Icecap ballasts side by side. Every summer when I change them, the Icecaps driven bulbs have more color shift compared to the new bulbs that I plug in to compare, and look much duller. Of course, they are duller right off the bat (an IC driven bulb might only get 80% of the output of the same bulb on HQI), but I mean more than just this... I mean ALOT duller than the one on HQI.

Until e-ballasts run HQI bulbs at the same outputs that HQI ballasts do, I question their use. E-ballasts were designed to use less power, yes, but they also put out less light, and it seems pretty proportional as well. On my pheonix 14,000K bulbs for instance, the PPFD of one on a HQI ballast is 88, and on a IC, its 73. According to my Kill-O-Watt meter, the IC ballast uses about 260watts to run this bulb (2 months old), and the HQI uses about 310 watts to run the same bulb. Wait, so thats a 20% increase in output for a 19.2% increase in power? Hey, that makes the HQI ballast more efficient from the watts/PAR standpoint. Sure, the IC can claim lower electrical costs, but its not as if its for free. Long term tests of pheonix bulbs on HQI ballasts showed drops of only 10%... I wish that was the case on my IC ballast. So for me, there is little to no point in running e-ballasts with DE bulbs. Sure, with SE/probe bulbs, they extend life and really are the best option IMO, but with DE bulbs they dont seem to be worth it. Now, when I say best option, I mean IF you are going to go with SE bulbs... all the longevity boosting that a IC ballast might add to a SE bulb isnt going to make it last as long as a DE/HQI setup. Besides, my IC ballast causes all kinds of TV static, and its 15' away. My HQI makes no such problems.