cold cathode lamps for amp - not PC

[dave]

I'd like to illuminate a bass amp by placing a cold cathode lamp inside - the
kind of lamp they sell for PC illumination. Trouble is I have no idea how to
power the lamp from the er amp! From what I understand, the lamps can be plugged
into one of the PC psu output sockets as they (the lamps) have build in
inverters. (true?). I don't want to introduce some horrible electrical inverter
noise in the amp output - would it be better to build a small dc psu just for
the lamp?
tia

 

[Kevin McMurtrie]

In article <0jvqf0t8972blg5iu7j0gltnfocm9ldtnc@4ax.com>,
dave <dave@nonet.here> wrote:

I'd like to illuminate a bass amp by placing a cold cathode lamp inside - the
kind of lamp they sell for PC illumination. Trouble is I have no idea how to
power the lamp from the er amp! From what I understand, the lamps can be
plugged
into one of the PC psu output sockets as they (the lamps) have build in
inverters. (true?). I don't want to introduce some horrible electrical
inverter
noise in the amp output - would it be better to build a small dc psu just for
the lamp?
tia

They're powered by 12V DC. I don't think you'd want one in an audio
amp. They radiate massive amounts in electrical noise not far above the
audio spectrum. I suggest using colored LEDs instead.

 

[Don Klipstein]

In article <0jvqf0t8972blg5iu7j0gltnfocm9ldtnc@4ax.com>, dave wrote:

I'd like to illuminate a bass amp by placing a cold cathode lamp inside
- the kind of lamp they sell for PC illumination. Trouble is I have no
idea how to power the lamp from the er amp! From what I understand, the
lamps can be plugged into one of the PC psu output sockets as they (the
lamps) have build in inverters. (true?). I don't want to introduce some
horrible electrical inverter noise in the amp output - would it be better
to build a small dc psu just forthe lamp?

To run a CCFL with DC, you can require a kilovolt or two (possibly
more) to start it. The voltage required for starting may vary with
temperature, presence of cosmic rays, random factors, etc. so a given
voltage may turn out to be unreliable at achieving starting. Starting
with AC is easier. With either DC or AC, starting is likely to be
easier if you put a conductive ring or band around one end and connect
that ring to the other end.
The voltage drop once it starts is a couple hundred to maybe a few
hundred volts.
One DC problem that I foresee: The mercury vapor may concentrate
towards one end. Another is that the negative end will get hotter than
the positive end. Most CCFLs want AC.

I suggest using a different light source (another poster suggests
LEDs) or else you may be in for a big shielding job.

- Don Klipstein (don@misty.com)