I think I would again mention the xenon flash lamp example.
There is NO need to ballast the flash lamp IF you have considered the
watt/seconds you will be dissipating in the lamp.
With enough capacitance/voltage, you can affect the life of the lamp.

How many have seen appliances with flickering or dead neon lamps?
Yes, they have a limited lifetime, even when run at the recommended current.

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-----Original Message-----
From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of
David VanHorn
Sent: Friday, September 28, 2007 12:45 AM
To: Microcontroller discussion list - Public.
Subject: Re: [EE] Neon lamps

On 9/27/07, Peter P. <plpeter2006@yahoo.com> wrote:
> David VanHorn <microbrix <at> gmail.com> writes:
>
> Neons die if they run directly off a cap. Replace them and put a
reasonable
> resistor in series with each to limit the current. I'd try 1K 1W for about
100mA
> inrush assuming Vign=140V and Vburn=70V.

I've NEVER seen the circuit done with a second resistor like that.


> This is more than 50 times their
> operating current afaik but it might keep them alive longer. In general
you
> should never connect something with negative resistance directly to a
voltage
> source (like a charged cap).

That's the whole point of a relaxation oscillator, isn't it?
I've done it with tunnel diodes, UJTs, and neons before.
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