Xref: utzoo sci.electronics:3218 sci.physics:3729 rec.pets:3003 misc.wanted:2539 misc.consumers:5579 Path: utzoo!utgpu!water!watmath!clyde!att!chinet!mcdchg!ddsw1!igloo!learn From: learn@igloo.UUCP (william vajk) Newsgroups: sci.electronics,sci.physics,rec.pets,misc.wanted,misc.consumers Subject: Re: Need information about metal halide lights Keywords: Metal halide lights Message-ID: <770@igloo.UUCP> Date: 4 Jul 88 23:00:21 GMT References: <523@rbdc.UUCP> <5164@ihlpf.ATT.COM> <525@rbdc.UUCP> Organization: igloo, Northbrook, IL Lines: 26 In article <525@rbdc.UUCP> Andy Pitts writes: > have had one person tell me that the lamps are interchangable in some ballasts > which are labeled for use with either type of lamp. A lot of old street lamps > have ballasts with little or no labeling and I still would like to know > if metal halides will work with these ballasts. The metal halide ballasts cost a lot more than the mercury vapor variety because of design considerations. The price of those ballasts usually has a lot to do with this sort of question which arises from time to time in my business, electrical contracting. To be brief, any ballast which might handle both sorts of lamps always does so at the additional cost of shortened bulb life unless you have paid a higher price for a ballast with multiple windings especially designed for multiple purposes. I've heard of such ballasts, but have not found any in my collection of catalogs, and have never had occasion to need one. If you're technically proficient at design, you might attempt to create a solid state ballast, otherwise you'll have to bite the bullet and pay for the standard unit designed for use with metal halide lamps. I further recommend that you acquire a complete unit with appropriate shielding for RF considerations. These bulbs are of the arc variety. Bill Vajk learn@igloo