FACTS:

DANGER- When working with household current please take all necessary precautions. If you are unsure of what you are doing, get some help from someone who does. Capacitors can be lethal; they can store dangerous voltage even after the power is off and must be discharged prior to working with them. They should be discharged with a large resistor. You can use a toaster to function as your resistor if you must. (This is a disclaimer and is being extra cautious, however it has been brought to my attention that coil ballasts have a resistor on board that serves to discharge the capacitor on shutdown. If in doubt it is always best to be on the safe side when dealing with capacitors.)

In order to produce light, metal halide lamps ionize gas within an arc tube. Once an arc has been struck, resistance to the current flow in these lamps is virtually nonexistent. As a result, without a ballast to control the current, the lamp would be destroyed.

Ballasts and lamps are given an ANSI (American National Standards Institute) rating. The ANSI rating # will give you the lamp type and wattage and no lamp or ballast of a different type or wattage will have the same rating #.

There are currently four ratings of ballasts that are of interests to us:

1. M59 -This ballast is used for the old tech probe start 400W metal halide bulb. In particular, it will run the MH400U and the EYE bulb that has been successfully used in many Lumenlab projectors to date. It will run ANY bulb with the M59 rating.

Probe start ballasts have a low current limiting factor because the ballast must be able to supply both a starting and a running voltage. Because of this, lamp efficiency/life is not as good as a pulse start system.

This is the cheapest option and still is used by builders on a very tight budget but is the least desirable because of improvements made with the pulse start system and the electronic ballast.

2. M135/155 -This ballast is made to run the new technology pulse start lamps (eg. Venture-400W/H75/ED28/PS and Ushio-MH400/U/MOG/40/PS). It will run ANY bulb with an M135 rating. Whether or not your M135 ballast also has the 155 designation is of no consequence unless at some point a M155 lamp is specified for the projector. Currently I don't believe that there are any lamps made that solely carry the M155 rating.

Pulse start technology improves the overall performance of metal halide. Lumen output per watt consumed increases by 25% to 50%, depending on lamp wattage and burning cycle, and lumen maintenance is improved as much as 15-25%. In addition, lamp life is extended, color rendition is improved, and warm-up time and restrike time (time from lamp extinguishing until it is cool enough to be started) is cut in half.

Pulse-start metal halide ballasts specifically meet the needs of pulse-start lamps and are not simply probe-start ballasts with added ignitors. Replacing the internal lamp starting probe with an ignitor allows a separation of ballast starting and operating functions. The ignitor starts the lamp and the ballasts' core and coil operates the lamp, allowing for optimization of both lamp and ballast performance.

The traditional CWA metal halide ballast, with its 600v peak open circuit voltage needed to start probe-start metal halide lamps, creates a relatively high lamp current crest factor that compromises lamp performance. Focusing the ballast design solely on lamp operation lowers the lamp current crest factor - resulting in improved lamp life, lumen maintenance and color stability. Isolating lamp starting and operating functions also result in more efficient and cooler ballast operation, as the core and coil no longer needs to supply the 600v starting voltage. This lower open circuit voltage creates lower ballast operating temperatures, resulting in longer ballast life.

Optimized pulse-start ballast/lamp systems boost maintained lumen output by 25% to 50%. Improving the quality and quantity of white light throughout lamp life provides energy savings, since lower wattage pulse-start lamps produce the same light output as higher wattage probe-start lamps. By achieving lumen maintenance of up to 80%, pulse-start lamps reduce light loss over the life by up to one-third compared to probe-start metal halide. Other improvements of pulse-start ballast/lamp systems over traditional probe-start systems are in color rendition, lamp-to-lamp color consistency, and reduced color shift.

This option is between the probe start ballast and the electronic ballast in cost.

3. The Electronic Ballast- This is the Cadillac of ballasts. It has many features that makes it the ultimate ballast for use in projectors.

An electronic ballast uses solid state components to transform voltage. It also changes the frequency of the power from 60 Hz to 20,000 Hz, or higher, depending on the ballast. Because the electronic ballast doesn't use coils and electromagnetic fields, it can function more efficiently and cooler than magnetic. The frequency change also greatly reduces any flicker in the lamp due to burn in or improper power and makes the ballast quiet. Coil ballasts suffer from a 60 cycle hum that can be annoying if the sound is amplified by the enclosure (the hum is similar to the hum of flourescent lights). Also, electronic ballasts are capable of even higher lumen output and longer lamp life than a pulse start coil ballast, and they weigh much less than either coil ballast (coil is ~15lbs). They are as simple as it gets to wire and you don't have to deal with the potentially lethal voltage of a capacitor. It can run pretty much any lamp of the same wattage currently used in Lumenlab projectors.

Some eballasts are unnecessarily bulky and can be quite expensive (eg. the Blueline). Lumenlab has gone to great lengths to supply us with a very compact and light (2.5lbs and measures 2.25" x 3.5" x 7") ballasts that can be purchased in the Lumenlab store. The price for this ballast cannot be beat. They go very quickly so get them fast when they are in stock.

4. S51 - This ballast was originally made for a 400W HPS (high pressure sodium) lamp. It is of interest to us because of manufacturers making metal halide conversion bulbs that will run on these. For some reason these bulbs (the Ushio UHI-S400DD in particular) have better color temp and CRI. This can be squeezed in the the 15" projector and it is ideally suited for use with a 17" and larger panel. Also the fact that it is a tubular shaped bulb makes it suited to new experimental reflector designs. For use with a coil ballast, an ignitor must be used. It can also be run with an electronic ballast.

FAQs:

Q: Why does my capacitor look different than some I have seen?
A: There are dry film caps and oil filled caps, either type will work as long as they have the proper rating. Dry film caps look like a plastic cylinder while oil filled ones look like an aluminum can, some are oval.

Q: How can I tell which way to hook up my capacitor?
A: Most caps are not polarized and can be wired either way. If there are no markings on the terminals or color coding on the wires, then it won't matter.

Q: How do I wire my ballast?
A: Most ballasts have a wiring diagram printed on them. If you don't understand it, get some help from someone who does.

Q: Can I use a probe start bulb on a pulse start coil ballast?
A: Yes, but you will likely void the manufacturers warranty on the ballast and the bulb. It may be difficult to start and you will lose the benefits of a pulse start system.

Q: Can I use a pulse start lamp with a probe start coil ballast?
A: No, you may get it to start but it will not light the lamp reliably.

Q: Why won't my lamp start?
A: Your lamp may not start because: there is no power to the ballast; it's the end of the normal lamp life; wiring may be defective or wrong; voltage may be too low; ballast is incompatible, defective or at end-of-life; lamp operating position may be wrong; not enough time for hot restrike has been allowed; high voltage restrike has occurred; or defective or mismatched ignitor is being used.

Q: Why does my lamp flicker?
A: New lamps may "cycle" during initial startup. If the lamp does not stabilize after three starts, reasons may be: wrong ballast; incorrect lamp operating voltage/open circuit ballast voltage; or overloaded circuits.

Q: Why doesn't my lamp make contact with the socket?
A: The lamp is not the correct one for the socket type. The mogul (standard) ANSI - E39 accepts all mogul-based metal halide lamps except position-oriented HOR lamps. The mogul (positioned) ANSI - EP39 accepts universal and horizontally positioned lamps. The E39 is white and the EP39 is yellow.

Q: Can I just add an ignitor to a standard CWA ballast to make it a pulse start?
A: No.

Q: Can I mix different manufacturers ignitors with different manufacturers ballasts.
A: No, all manufacturers recommend using their ignitors with their ballasts.

Q: Can I mix capacitors?
A: Yes, as long as it has the same specs. (capacitor type, µf and voltage ratings)

Q: What is a quad tap ballast?
A: A quad tap ballast has four different input voltages, just connect the proper voltage for your household current and leave the others unused but capped off.

Q: Which of the above mentioned types of ballasts will the Lumenlab electronic ballast replace?
A: Both of the metal halide ballasts. There may be a special eballast made available to replace the HPS coil ballast. I would recommend checking with the Lumenlab store at the time of purchase to be sure that it is compatible with your lamp.

LINKS:

For those who wish to delve deeper into ballasts, here is a handy reference. Holophane Ballast Handbook (PDF)

Here are some onsite links to ask your questions:

Ballast wiring
ballast & lighting
Electronic ballast wiring
Placement of ballast
Lumenlab electronic ballast (review)
Would this ballast work?
What kind of ballast is needed? (UHI-S400DD Ushio)
Wiring the ballast (circuit)

Sorry this was so long, I hope you found it helpful and informative.

One last thing: The only posts on this thread that will not be removed without mercy are corrections, addendums, links to valuable ballast information (no direct competitors please) and FAQs with both the questions and answers. Questions can be asked on the links that I and others have provided (possibly your answer is already there). Try to find a link that is on your topic or start your own topic if you must. If you get some good info in your thread, it would be nice if you came back to this thread and posted a link.

Please post any suggestions/comments reguarding this thread at the Suggestions for using the forum thread.

Thanks Much

Here is an informative page on ballast troubleshooting and how to test with a meter.

http://www.sperolighting.com/ballast.html

CAUTION : Failure to follow the procedures in this troubleshooting guide can be very dangerous. An ignitor can put out lethal voltage. Do not try this if you are not absolutely certain of what you are doing.

NEVER try to test an electronic ballast's output voltage.

Here's a thread origionally moved from this page, but it ended up having some good info in it, so here's a link.

http://www.lumenlab.com/forums/index.php?showtopic=3246&hl=

After awhile of use my eballast makes a really annoying high pitch hum. Any clue how I can stop this, before I take a bat to it?


Thanks,
Kevin

Use ear plugs??
Actually eballast are supposed to be quiet as they operate a 10KHz while the coil and cap ballasts can only operate 60Hz US and Canada and 50Hz Europe. So you really shouldn't hear anything, some thing must be loose, try moving the eballast and see if anothre angle stops the hum.

mm, where did you find the 10Khz operating frecuency for the ebalast?

anyway it is perfectly audible that frecuency (up to 18Khz for me, but generically 20Khz for humans)

Yea I was using a cap ballast and it was really annoying so i switched to the eballast. Tell you the truth this high pitch noise is far more annoying, to the point i'd rather not even watch anything.

I'll try moving it and stuff, if all else fails I guess I'll be taking it apart this weekend.

Sorry 10KHz was a typo, I ment top type 100KHz, a little research seem to suggest that they run 25-100KHz.

Is it possible to use a hacked 400 watt computer power supply as a 400 watt ballast?

No. Wattage, wires coming out, and the fact that they both plug into the wall are the only things a PC power supply and a ballast have in common.

The ballast (electronic or coil & core) provides a starting voltage to strike the arc, usually measured in kV, and then a current-limited lower voltage to keep the arc alive. No DIY construction for kV devices, please.

So then what is the difference between a 400w H33 Ballast -Metal Halide this: http://www.hellolights.com/40magmagm59b.html

and a 400w ballast as to what lumenlabs sell, this:
http://www.hellolights.com/40bl1rebasus.html


And also what is the diff. between a Hp and a MH?

BTW will something like this work in building a projector:

400 watt Metal Halide Complete Ballast Kit
400 watt METAL HALIDE ( MH )

Ballast Kit

Includes:

1 - 400 watt Low Heat METAL HALIDE Ballast

1 - 400 watt METAL HALIDE Capacitor

1 - Mogul Based 5KV Pulse Rated Socket with fine threaded 8/32 bolts

5 - High Temperature Wire Connectors