> 3) $2.00 from orchard supply =A0 - has 1 amorphous solar cell on glass (1=
..33 in circuit w bright light, 1 IC (pn 5252F) w 4 leads =A01 aa NiCd cell =
=A01 white LED 1 inductor. same inductor story.
> Tag says made for Orchard Supply in China
> The circuit in this one is as follows:
> pin 1 of IC has Sol+
> pin2 B+ and L
> pin3 B-, Sol-, Led-
> pin4 Led+, and L
>
> Can't find any such chips on Google. But if you could, it might be a good=
 thing for the solar guitar tuner, I bet (at least $0.25) the chip has a bo=
ost current source that could be a voltage source with a bit of tweaking - =
diode + cap =A0+ Zener?. You could go to OSH for the chips and all for $2.
>
> Note the NiMh button cell in #1 =A0(a solution to some size objection to =
NiCd s by the OP.)
> Note - none of these have visable diodes in series w the solar cell - =A0=
 and the cell V was too low to allow one in #1 and #3 (1.3V in circuit, per=
haps a fet is used to block reverse current to the solar cell?

Similar:

Reasonably nice boost converter
Uses external FET which is a major advantage in real applications and
has Feedback in some versions.
Starts at 0.9V.
External FET makes rubbish of internal curves which are example only.
Sufficient unto the L & FET & Schottky diode is the efficiency
thereof.
Probably around 10 cents in modest volume.

           http://www.lrc.cn/data/pdf/LR9908.pdf

LRC are/were a 50/50 joint venture with Motorola in China.


LRC products page.
Some older Motorola products feature in their product set.

                http://www.lrc.cn/english/product.asp

DC-DC

  http://www.lrc.cn/english/element_list.asp?id=3D461

Synchronous buck.
Limited range but useful

   http://www.lrc.cn/data/pdf/LR8506.pdf

Ye olde MC34063 -> LR34063.I pay about 10 cents for these.
Was less but ...

                http://www.lrc.cn/data/pdf/LR34063.pdf

Cheap and cheerfil boost

      http://www.lrc.cn/data/pdf/LR8301.pdf

LR2596 3A 40V buck.
Familiar
Nicish

    http://www.lrc.cn/data/pdf/LR2596.pdf

Finding a US supplier may be difficult.
If you find one please tell me.
I can get them in NZ, surprisingly.
Hong Kong (and Singapore and Souty Africa and ...)  Mobicon can supply.


    Russell

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