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GregS[_3_] GregS[_3_] is offline
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Default Thorens TD 126 MK II electonic

In article , jakdedert wrote:
Chris Hornbeck wrote:
On Thu, 13 Nov 2008 17:27:58 +1100, "Trevor Wilson"
wrote:

**I've done a few of these with LEDs. The original neon was a big
(expensive) sucker. MUCH larger than NE-2 and other types. If you can find a


friend with some electronic nouse, ask them to wire up some nice, bright
LEDs (blue ones look way cool) in place of the neon. The result will be a
long lasting, bright and clear speed indicator. Naturally, you need to drive


the LED with mains frequency. This is not difficult stuff.


Several caveats:

NE-2's should be free from anybody over a certain age, if you know
what I mean. Geezers have boxes of 'em. No magic was involved in
their manufacture and they last for many decades.

Neons fired bidirectionally (120Hz for 60Hz Edison). LED's don't.

Neons arc'd over at about 60 to 80 volts. LED's are semiconductors
and operate a little differently...


But an easily visible green LED would be a substantial improvement
for strobe use, if all else were taken into account.

All the best fortune,
Chris Hornbeck


Off the top of my head, wouldn't a pair of LEDs, each firing from the
opposite phase of the AC, visually sum to a 120Hz 'flicker'?



Right..You can also use a bridge to drive one. I think the orinal neon
was fairly long, but that no problem. You can use a light guide or multiple LED's
My preference is blue, but blue has a lot more fogging effect than red or orange.
You can use large resistors to drive from HV lines. It's
just is way less efficient.

greg