ZAP!!!

[ffutures]

This evening's pound shop bargain was a small USB accessory. A glass ball about the size of a light bulb on a plastic base...




Yes, it really is a USB-powered plasma globe. I have no idea how they get the necessary voltage for it, but it's really quite nifty. Not as nice or as bright as the 6" globe I got a few years back, but it's a fun toy. And if I can pick up a few more various family members will be getting them as stocking fillers...

Comments

[pengshui-master.livejournal.com]

I have no idea how they get the necessary voltage

Hmm. The usual trick - violate the USB spec (eg, draw current beyond the spec andr/o don't bother with negotiation ) and then use an oscillator to create a Dc-dc converter?

[ffutures.livejournal.com]

The base is marked 5V 300ma, is that violating it?

[pengshui-master.livejournal.com]

IIRC anything more than 100mA has to be specifically negotiated with the host. - Which would require a microcontroller.

OTOH These days the may be some one-chip solutions from people like maxwell that do it all.

[ffutures.livejournal.com]

No chips as far as I can tell - it's just a cable with a USB plug at one end and a jack at the other.

[gonzo21.livejournal.com]

That's almost disturbingly fabulous.

[curiouswombat.livejournal.com]

Ooh! That's rather neat!

[raygungothic.livejournal.com]

Bloomin' 'eck, plasma off USB for a quid?!? Where?

[ffutures.livejournal.com]

I'll say where once I've gone back and bought a few more...

[raygungothic.livejournal.com]

Fair enough! I hope they have lots... nothing like that in pound stores near me.