Re: Tektronix Neon Light replacement parts?


n4buq
 

The most fun with a neon is, in the wintertime, to hold one lead of a neon bulb between your thumb and finger, scrub your shoes across the carpet, and then touch the other lead to ground (or to someone else who has a significantly lower ground potential than you do at the moment).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Harvey White" <madyn@dragonworks.info>
To: TekScopes@groups.io
Sent: Thursday, January 24, 2019 1:35:41 PM
Subject: Re: [TekScopes] Tektronix Neon Light replacement parts?

On Thu, 24 Jan 2019 19:01:23 +0000 (UTC), you wrote:

There's two ways of using a neon lamp. One is a simple indicator to
show that there is voltage or current. Typically, about 1.2 ma or so
goes through the lamp (120 volts/100K or so ohms). The NE2H varieties
take about twice the current and are brighter (H = high brightness).

The other way is to use it much like a zener, that is, to limit the
voltage differential between two points in a circuit. When the lamp
fires (the strike voltage), it starts to conduct, which causes current
to go through it, limiting the voltage to what's called the
"maintaining voltage". The maintaining voltage is lower than the
strike voltage.

Supposedly, the temporary overvoltage condition goes away, voltage
across the lamp goes below the maintaining voltage, and the circuit is
protected.

A zener diode works just about the same way, but is more stable, and
has effectively tighter tolerances.

Harvey

Join TekScopes@groups.io to automatically receive all group messages.