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UV Power supplies & electronics?

Chi-Bin Chien chi-bin.chien at hsc.utah.edu
Sun Jul 12 16:44:12 EST 1998

Re the thread about killing electronics by lighting mercury arc lamps:

My understanding is as follows:

The problem comes when you are lighting your mercury lamp, because the
mercury needs to somehow get vaporized for the bulb to work. At least with
older power supplies, this was done by running a high-voltage spark through
the bulb. (I am not quite sure if newer power supplies can somehow do this
more gently.)

This high-voltage pulse has to be carried by the cord that runs from your
power supply to the lamp, and the cord acts as a broadcasting antenna. The
broadcast pulse can then induce surges in nearby equipment and cause
problems. The power of the interference should decrease approximately with
the inverse square law, ie distance does indeed help. Finally, another way
to decrease the interference would be to reduce the length of the antenna:
I imagine that putting the power supply pretty close to the lamp and
folding the cord should help. I have heard that Optiquip makes a power
supply in which the ignitor is mounted directly on the lamphouse, reducing
the antenna length to virtually nil and obviating this problem.

Any corrections from more authoritative sources are welcome.

--Chi-Bin Chien

< Dept. Neurobiology and Anatomy |       office: 1-801-585-1701 >
< Univ. Utah Med. Center         |          lab: 1-801-585-1702 >
< 50 North Medical Drive.        |          fax: 1-801-581-4233 >
< Salt Lake City, UT  84132      |   chi-bin.chien at hsc.utah.edu >

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