Ballast question

[Finious]

I am about to buy a ballast for the 2x400w mogul xm 20k's i just got. I have heard here that PFO's are good. 1) can anyone support that? (are they good). 2) I am think of getting the duel 400w ballast, from looking at dealers i have found i want a reg. one (not hqi or eye) but i am confused on what the difference is between tar and pulse start. Thanx for any help.

[KevinM]

First, keep in mind that PFO doesn't actually make ballasts, they make enclosures. If you open that enclosure, you'll likely find either an Advance, or a Magnatek ballast inside.

A pulse-start ballast can be either "tar" (magnetic) or electronic. So can a probe-start. The difference comes in how they strike the arc in the lamp. A pulse-start ballast strikes the arc by shooting a very high current pulse (from a capacitor) down one of the main electrodes, and BLAM...an arc is created between the two main electrodes.
In a probe-start ballast, there is an additional electrode inside the arc-tube that comes very close to the end of one of the main electrodes (similar to what you see on a barbecue grill with an electric ignitor, when you push the button a spark jumps from the electrode to the frame of the burner). A current passes (from an ignitor, similar to a capacitor) into this additional electrode, a spark jumps over to the main electrode, and BLAM...an arc is created.

The PFO ballasts will do just fine for you. You *will* want to be sure to get pulse-start for your XMs.

HTH,
Kev

[Finious]

KevinM Thanx alot that is what i needed to know. Learning new things all the time