cold cathode lamps for amp - not PC

- D
- dave
  
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posted
19 years ago

Tue, Jul 20, 2004 9:26 PM

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

- K
- Kevin McMurtrie
  
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posted
19 years ago

Thu, Jul 22, 2004 4:44 AM

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.

- D
- Don Klipstein
  
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posted
19 years ago

Sat, Jul 24, 2004 5:56 PM

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 ( snipped-for-privacy@misty.com)