1.5v To 5v...

[li_gangyi]

Ok here's a really good challenge...I haven been able to answer this...how can someone convert 1.5V or less to 3V or more?? My friend has a solar panel that goes 1.2V MAX and has 2A output...yikes~!! But he wants to drive a small motor...and they dun usually run well till u feed in 3V...how do I do that?? Seems like a total dark area for me...

[wintermute]

Do a search on DC-DC inverter. Don't know anything about how they work, but I think it's what you are after.

maybe the car audio forum can help, you need a lot more than 12V for high powered amps, so I imagine they use inverters to bump up the voltage too.

Regards,

Tony.

[li_gangyi]

many funky designs...but none work at 1V...as far as I can tell..it's a bit hard coz not many transistors turn fully on...

[Bakmeel]

I've had to solve a similar problem for a practicum electrical engineering... It's not easy, but it can be done... The cirquit you need is called a "Boost Converter", and it can be designed for allmost all voltage and power ratings.

The principle operation is like this:

(Image nicked from Fairchild Semiconductor Site)

First, the left FET allows current to flow through the coil, and energy is stored in the coil's self inductance. Then, the left FET blocks, and the right is set to conduct, the coil wants to maintain current flow, so the energy stored is "boosted" to the output network. Before the coils energy is depleted, the FET's switch operation, and the coil is charged again... This process repeats at around several kiloherz.

The morale: Do some googleing on Boost Converters, and find some chips that support the ratings you specify.

Bouke

[li_gangyi]

hmmm...looking for specific chips that can work with 1.5V is gonna be hard...

[Vinnie R.]

The lowest input voltage I've seen on one of these is 1.8V, and it can be converted to 3.6V I believe.

[Vinnie R.]

Well, actually, there are topologies that can take low voltages (ex. 0.7V) and can output 3.3V, but the max power out is 1W. Is this enough? For a motor, I think you are going to want more current.

[li_gangyi]

I'm probably gonna need at least 300mA...where can I get that...seems like pretty hard to do it...even a 555 can't work at 1V...GRRRR

[Vinnie R.]

I found an IC by Zetex Inc.
The part is ZXSC100

If you go to www.digikey.com, search for
ZXSC100N8CT-ND

This is a 2W chip. You can download the datasheet
from digikey. It costs $1.97 USD, buy you'll also
need discrete parts like an inductor, diode, FETs, etc.

Take a look

Regards,

Vinnie

[davesaudio]

I know this works to run a pic 5v 30ma or so
http://www.bobblick.com/techref/proj...l/up1cell.html