Light sensitive neon?

[dR-Green]

Greetings. Maybe someone out there knows what's going on here? Then again maybe I'm just ignorant of how neons work?? Either way I've never come across anyone else mention this before so here goes... Last night I was playing around with connecting the output of the SG to a 240v to 12-0-12v transformer to see what would happen. With the SG connected to the 240v input end and no load on the transformer output, the neon was flickering away. But here is the strange thing. The lamp I was using to light the room is a regular CFL, and when I moved my head to examine the machine I happened to be causing a shadow over the SG... The neon went off. I moved my head away to allow the light on it, and the neon came back on. I could get the same effect by moving my hand over it but it wasn't as effective, I assume because the shadow of my hand is smaller than my head. I only focused my attention on the neon for a couple of minutes before I tried something else, but later I was thinking maybe it wasn't just the light falling on the neon that was causing the effect, but maybe light falling on the coil or something even more weird like that. So I'll have to repeat the same setup again later and fiddle about some more.

FYI, after I initially noticed the effect, I "tuned" the pot so that the neon was just about lit, so the difference between "on" and "off" was obviously noticeable and easily achieved through blocking the light from the CFL lamp. (Too little resistance and the neon will be permanently lit no matter what you do). The transformer I used was this, the 12v one.

Miniature 250mA Transformers : Mains Transformers : Maplin

The primary winding is around 560 ohms (but I'll have to measure it again to be sure), and the 5-9 ohm secondary windings couldn't produce the same effect.

[citfta]

Perfectly normal

Hi dR-Green,

What you are seeing is a normal action for a neon. A neon is called that because it contains neon gas. When energized neon glows. If you look closely inside a neon you will see there is no filament like a regular incandescent bulb has. There are only two small wires sticking up beside one another with a space between them. When you apply voltage to the wires you are energizing the gas in the bulb. If you energize it enough the gas begins to glow. You can also energize the gas with light and cause it to glow although normally you would not see it because the light alone would have to be very strong to cause the gas to glow. If you have the voltage just high enough to almost cause the gas to glow then the extra energy from the light hitting the gas is enough to push the gas over the edge and make it glow. Hope this helps.

Carroll

[Slider2732]

If i'm reading your situ correctly, you may enjoy the Joulethief circuits thread also on the front page of topics in this section.
Lighting neons by wireless induction is quite commonplace and, I believe, relates also to the phenomena you experienced. The small transformer is radiating wireless energy strong enough to affect the neon
The acid test of which, is to bring the neon bulb close up to the transformer...if it lights stronger the closer it gets, you have electromagnetic induction.
Our own bodies can also benefit the lighting of a neon, through body capacitance. If you hold a neon in your hand while within a wireless field, the light will glow much easier than simply sat on a table with you nowhere near.

If I might link to one quite graphic example of my own experiments..this video shows some experiments yesterday with a Slayer circuit (Slayer007 here on the board) that lights a regular neon lamp to a few inches wirelessly. Those experiments were based on a T shaped antenna for field expansion, using the low voltage from a Nokia phone charger and pill bottle 'Walgreen' Tesla tower.

YouTube - Dipole wireless field !!!

[dR-Green]

You can also energize the gas with light and cause it to glow although normally you would not see it because the light alone would have to be very strong to cause the gas to glow. If you have the voltage just high enough to almost cause the gas to glow then the extra energy from the light hitting the gas is enough to push the gas over the edge and make it glow. Hope this helps.

Carroll

Thanks Carroll, that does help Very strange and cool thing to see though

[dR-Green]

If i'm reading your situ correctly, you may enjoy the Joulethief circuits thread also on the front page of topics in this section.
Lighting neons by wireless induction is quite commonplace and, I believe, relates also to the phenomena you experienced. The small transformer is radiating wireless energy strong enough to affect the neon
The acid test of which, is to bring the neon bulb close up to the transformer...if it lights stronger the closer it gets, you have electromagnetic induction.
Our own bodies can also benefit the lighting of a neon, through body capacitance. If you hold a neon in your hand while within a wireless field, the light will glow much easier than simply sat on a table with you nowhere near.

If I might link to one quite graphic example of my own experiments..this video shows some experiments yesterday with a Slayer circuit (Slayer007 here on the board) that lights a regular neon lamp to a few inches wirelessly. Those experiments were based on a T shaped antenna for field expansion, using the low voltage from a Nokia phone charger and pill bottle 'Walgreen' Tesla tower.

YouTube - Dipole wireless field !!!

Very nice video. I'll look into this Joule Thief business now, I might give it a try tonight if I have the parts. I'll check out your other videos too, thanks