Neon Power?

[Trout]

OK, This might of been a joke, I found it on another forum, (guitar amp)

BUT, I had to post it, Neon Tubes as output tubes? Is this actually possible?

Neon Power

There is a web address on the drawing, But I have not been able to locate it or any web refs to it.

Trout

[edl]

Yeah, you are right, that's only a joke.

More funny schemas:
http://www.kepfeltoltes.hu/060420/Ne...toltes.hu_.gif
http://www.kepfeltoltes.hu/060418/Er...toltes.hu_.jpg

[Trout]

haha, Thats Cute!!!!!!!!!

[Makofoed-6sn7]

Hi,

Well, people DO make a lot of funny stuff...
Serious, It might work as the most heavey fuzz/clip box. If the neon tubes arn't glowing and you put on puls high enough on the coil for it to fire, you will get a click in the speaker. So it is a fine clip box.

[smoking-amp]

The so called Neon tubes appear to be 40 Watt fluorescent bulb tubes with 12 Volts on the heater filaments at one end to make them conduct in just one direction. Seems like it might be working, the wires coiled around the tubes acting like grids, but probably rather non-linear as the gas conducts.

UV rays are sometimes effective in getting a plasma to conduct, might be interesting to try a similar setup using the UV capable LEDs available these days, acting as "grid" controls at the filament end of the tubes.

Don

[gianis]

Nice schematics,,i`l try these....:

[smoking-amp]

One thing that would worry me about this "design" is that gas discharges usually have a negative resistance effect (ie, more current = lower resistance). This could lead to a runaway current conduction thru the output xfmr. Better put a 1 Ohm 1/2 Watt sacrificial film resistor in series with the B+ to protect the output xfmr in case that happens.

Maybe could put a resistance equal to the tube's negative resistance in series with each tube to prevent this (like a ballast for the normal AC drive case), but not too efficient then.

Another fixup could be to use two "Neon" tubes in parallel for each P-P side of the xfmr and drive each one with opposite phase half wave rectifried B+ (no B+ filter caps). That way any conduction latch-up gets cured every 8 or 10 milliseconds. Not too Hi-Fi then obviously.

Maybe could do SCR like phase control triggering of the tubes to get a more linear response. Or go to RF freq. power, so it would be out of the audio range. One might even try modulating the tube current with an electomagnet winding over the tube (field at right angle to tube length), but probably would require more power to do than the rated output.

If you just want visual effects, I would try putting the "Neon" tubes in series with the plates of some big pentodes. Their plates look like current sources, so they would override any "Neon" negative resistance effects.

Don

[bigwill]

I had this very idea the other day (Using gas discharge lamps as an output stage), even down to using a coil for the "grid"!

I wonder if you could get something workable, maybe some kind of class A amp?

[Trout]

Wouldnt this be truely fun if it actually works?

The Backlite effect from the tubes could be a nice feature, Get some funky old 60's blacklites and get a hype-delic glow

Better yet, Plant grow tubes, Then tell the wife that it needs funded for the bennifit of the house plants!

Those are 40W flouresent tubes, That means 48 inches each. I am fairly sure the 1500 turns of .9mm wire wont hide them completely and they do show some sort of heater hook up lol.
I wonder if coil position over the length will be tuneable?
Trout

[smoking-amp]

Those 40 Watt lamps probably draw about 400 mA to light them up, so unless you are planning on using some big FuFu pentodes to light them up, I would use some smaller lamps for visual effects only.

Can't help but wonder if someone has tried these lamps out in a HV power supply as a voltage regulator tube. Would have to measure the breakdown voltage. Might be variable depending on the current thru the end filament. Maybe could use an Op. Amp. servo loop to control the filament current to get the desired breakdown voltage.

There were some decorative neon/argon lamps made at one time that had fluorescent painted glowing figurines inside a clear bulb, these should work for VR tubes. Now if someone would just make some with appropriate figurines inside, maybe a portrait of Lee de Forest or Edison or an LP record or ....

Don