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-   -   VU light bulbs? (http://www.diyaudio.com/forums/solid-state/36655-vu-light-bulbs.html)

Pbassred 24th June 2004 11:13 PM

VU light bulbs?
 
2 Attachment(s)
what are those tiny light bulbs in VU meters? What voltage/current. AC? DC where can you buy them?

I bought an old piece of kit and I thought it was just blown bulbs. I've replaced the bulbs from meters salvaged from an old HH mixer, but a previous owner had dismantled the light circuit!

karma 24th June 2004 11:24 PM

u can pick em up at a hobby shop or radio shack. thay rang from 5v to 12v even 3v

karma 24th June 2004 11:26 PM

or replace it with some nice blue l.e.d's;)

imix500 25th June 2004 12:47 AM

...or a white EL panel.:)

Pbassred 25th June 2004 07:42 AM

.........yes but what are they CALLED? The UK Arm of Radio Shack (Tandy) no longer exists in the UK. I cant find them in the RS catalogue either.

jaycee 25th June 2004 08:28 AM

At a guess they're probably wire-ended lamps like RS stock code 339-0457. I'm pretty sure Maplin sell something similar but their website is down right now.

My guess is they will be 2x6V light bulbs wired in series and powered from a 12V line somewhere in the amp. The bulbs should run on either AC or DC, RS suggests they last longer running on AC but they may well have been DC powered.

Pbassred 25th June 2004 07:51 PM

Karma, your link does not work. :(

Jaycee, they are not wire ended. the contacts are brass wrapped around the side. They clip into the holders sideways. The piece of circuit that remains is a big resistor, (I forgot to note the value) and one lead connected directly to The neutral mains tag of the power switch (240v in the uk). The other end is gone.

I'd love to contact the makers of either piece of kit, but both Studiomaster and HH are long dead. Coincidently (or not?) one was in Cambridge, the other, in Hoddesdon. The Towns are 30 miles apart connected by the A10 main road.

Blue LEDs are starting to look attractive :)

dnsey 25th June 2004 08:32 PM

Sounds like they might be festoon lamps.
I tried to post a URL to an illustration, but it's too long to show up properly!
Search Maplin for 'Backlighting lamps'

jaycee 26th June 2004 11:38 AM

Hmm.. sounds like they were connected directly over the mains.This is a bad idea, in audio, as the VU's will be connected to the analog amplifier stage, you really don't want 50Hz mains near signal wiring!

See if you can find some suitable low voltage supply, 12V or so, inside the equipment, then wire 2 6v meter bulbs in series per meter to the supply. Or use LED's of any colour of your choice with the appropriate dropper resistor - white LEDs would work pretty well.

Pbassred 26th June 2004 01:10 PM

Hmmmmmmmmmmmmmmmm I agree!

I went looking for some 12 volt DC. This thing runs at 120VDC! I don't know how. :xeye: I once posted a thread about "why cant you run with rectified mains and ditch the transformer" But was told its dangerous and we don't allow such descussions here. This looks pretty close!

Anyway I think the plan is to make a low volt supply. One question though. LEDs run at 5V (no?). Why did you say 12V? Can you suggest a way to drop down from 120v (or 60V if I tap off one of the PSU caps)?


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