Weird HID noise

[sylathnie]

I just recently purchased a nice 14W HID here to play with. I've lit it up a few times and just recently it has begun to make an awful squeal. It has a bit of a pulse to it that slowly gets shorter the longer the light is on. The bulb doesn't seem to get to full brightness either.

I'm powering it (for testing purposes) off a 12V SLA.

Any thoughts?

 

[PhotonWrangler]

I just recently purchased a nice 14W HID here to play with. I've lit it up a few times and just recently it has begun to make an awful squeal. It has a bit of a pulse to it that slowly gets shorter the longer the light is on. The bulb doesn't seem to get to full brightness either.

I'm powering it (for testing purposes) off a 12V SLA.

Any thoughts?

Did it ever get to full brightness before the noise started? If it did, there could be a component failing in the inverter that's detuning it down into the audible range of frequencies. Or it could be as simple as a vibrating inductor.

 

[sylathnie]

Bah. The battery was the problem... under load it was dropping to less than 9 volts. Not under load it was at about 12.9 volts. Time to chuck that one I guess.
Figures... I have a $300 lab grade power supply... and I snag the old used SLA. :shrug: