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Re: Neon life (and death)




From: 	Bert Hickman[SMTP:bert.hickman-at-aquila-dot-com]
Reply To: 	bert.hickman-at-aquila-dot-com
Sent: 	Thursday, October 30, 1997 2:07 AM
To: 	Tesla List
Subject: 	Re: Neon life (and death)

Tesla List wrote:
> 
> From:   ghunter-at-mail.enterprise-dot-net[SMTP:ghunter-at-mail.enterprise-dot-net]
> Sent:   Wednesday, October 29, 1997 3:20 PM
> To:     tesla-at-pupman-dot-com
> Subject:        Neon life (and death)
> 
> What's the typical lifespan of a neon TC power supply?  One
> subscriber to the list has suggested that a pile of used neon
> transformers is good to have around, because they don't last very
> long.  I find this most disturbing, as I own only ONE neon
> transformer, and it wasn't free.  I've seen working luminous sign
> transformers in downtown New Orleans that appear to have been on
> continuous duty for decades.  Obviously, neons are built to last.  So
> why would a TC shorten the life of a neon so drastically? I'm aware
> of the need for output chokes, and mine will be protected with four
> (4) robust, home-made units (2 big air-cores, and 2 fat ferrite
> cores).  I'm also including a safety gap.  What more can I do?
> Series power resistors maybe?
> 
> Greg
> 
> 

Greg,

A typical neon sign transformer spends virtually all its life looking at
a few thousand voltas of output once the conduction neon tube has driven
the transformer into current-limit mode. In TC use, the transformer
typically sees voltage spikes well above its rated peak open-circuit
voltage, plus RF that can make it back to the secondary windings. The
combination of these two causes corona, and results in the destruction
of inter-turn insulation, ultimately destroying the fine secondary
windings. If you're planning to do serious coiling, you'll need to
locate a source of cheap neons. If your REALLY serious, then you'll
migrate to a potential transformer or a pole pig...

Safe coilin' to you!

-- Bert --