Strong 575w Followspot lamp flicker

[oftenatodds]

Hello All!

I've got 2 Strong 575w Followspots that both giving me some sicked lamp flicker. I've determined that it is not a mechanical issue, Both lamps are securely tightened into their sockets and resting on the Y arms. The lamps, Osram HMI 575/DXS, have only been used for 10 or so hours.

Any ideas? Wrong lamp? Dying power supply?

For bonus points, how does one go about bench focusing the units without having the lead on the Y arm side push the lamp up and to the side as you are trying to adjust the lamp depth.

 

[Les]

So, both spots are giving you the same issue? Are the spots on the same circuit?

If so, move one to another circuit and watch for any changes.

 

[PeteEngel]

Lamp Flicker on lamps with small amounts of hours does indicate that potentially the lamps were not properly burned in. Did you install the lamps, turn them on and leave them running for a minimum of 1/2 hr (more is better)? Arc lamps not properly burned in tend to flicker and rarely get better over time. also, Les makes a good point about power. check that they are on separate circuits. even though their nominal draw equals 1150w total, there is an initial inrush draw well in excess of that. also, if you have low voltage at your power source (100v as an example) you may be running at the hairy edge of what the power supply will tolerate before de-arcing the lamp, also causing flicker.

could be a few things. check them all out.

 

[JD]

A HMI 575 is inexpensive enough (relatively speaking) to have a spare. Pick up a new one, burn it in for 30 minutes, and see if it behaves well. If it does, put "flicker" in your spare stock and order another one for the other unit. Burn in is important, although I though most lamps these days had that done at the factory. (Haven't done it myself on several newer lamps, but did it religiously back in the 80's when an HMI 575 was $500. (Remember, satellite spots at first only sold them in the reflectors?) In any case, I could be flat out wrong about the factories doing any burn-in whatsoever, but it's a good idea to do 30 minutes if there is any question, so give it a try.

 

[JimOC_1]

As Less indicated, loose contact in the breaker box, wall outlet, adapter, or cable? All things found in our cafatorium. Surprisingly this was even true for a unibody adapter from a major vendor.