Is there such a toy?

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"Man-wai Chang" wrote in message
...

Is there such a toy?


Yes if you use a 1.5V blocking oscillator.

"Ian Field" wrote in message
...

"Man-wai Chang" wrote in message
...

Is there such a toy?


Yes if you use a 1.5V blocking oscillator.

http://cappels.org/dproj/ledpage/leddrv.htm

Yes if you use a 1.5V blocking oscillator.

http://cappels.org/dproj/ledpage/leddrv.htm

I want one that has the (over?) driver built into the LED...


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"Man-wai Chang" wrote in message
...
Yes if you use a 1.5V blocking oscillator.

http://cappels.org/dproj/ledpage/leddrv.htm

I want one that has the (over?) driver built into the LED...


Some time ago Elektor did a front cover freebie; a tiny PCB with a dedicated
LED drive chip and inductor for voltages down to 0.9V - that's probably as
small as it gets.

Can't remember details but if you google Elektor and click contact from
their home page, you can ask the editor.

On Fri, 28 Oct 2011 18:37:15 +0800, the renowned Man-wai Chang
wrote:


Is there such a toy?

You could use this simple circuit to work down to 1V --


FB = OUT for Red

FB = GND for Green/Blue/White
|
.----------.
Vin 0.8V minimum | FB |
10uH | |
___ | L6920 | LED
o----+---UUU----|LX OUT|----+-|---+
+ | | | | |
--- | | | |
--- | REF | | .-.
47uF | '----------' | | |
| | + | |
GND 100n --- --- '-'
--- 47uF --- |
| |
GND GND GND


All the parts can be tiny SMT components. Reduce the 47uF caps to 22uF
and use 0805 22uF/6.3V ceramics and an 0805 inductor to reduce size,
and the 100n can be an 0402.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Man-wai Chang" wrote in message
...
Yes if you use a 1.5V blocking oscillator.

http://cappels.org/dproj/ledpage/leddrv.htm

I want one that has the (over?) driver built into the LED...


http://www.elektor.com/magazines/200...er.58609.lynkx

On Sat, 29 Oct 2011 22:39:27 +0100, the renowned "Ian Field"
wrote:


"Man-wai Chang" wrote in message
...
Yes if you use a 1.5V blocking oscillator.

http://cappels.org/dproj/ledpage/leddrv.htm

I want one that has the (over?) driver built into the LED...


http://www.elektor.com/magazines/200...er.58609.lynkx


Presumably this part?

http://www.prema.com/pdf/pr4401.pdf


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com