how to boost 3V DC to 6V DC?

Thread Starter

hemnath

Joined Dec 12, 2012
20
I have to boost the voltage from 3V to 6V and looked into boost converters ic such as maxim, Linear technology, Analog devices,etc... But it needs an extra device to my circuit and cost more.
So I'm designing using simple joule thief. Is it possible to boost the voltage 3V to 6V using joule thief? else, is there any possible solutions to boost?

Thanks in advance :)
 

chunkmartinez

Joined Jan 6, 2007
180
Idk what joule theif is but I would look for one of those switching dc/dc boosters. They are much more efficient then most of the linear boosters.
 

ErnieM

Joined Apr 24, 2011
8,377
Assuming this is a very low current application a charge pump IC may better suit your needs. A device such as the MAX1682 voltage doubler just needs two 10uF caps to double the voltage, though it comes in a SOT-23-5 surface mounted package. It operates over a 2.0 to 5.5 V range.

These devices work by charging one cap, then discharging that cap into another cap to get the double voltage.
 

wayneh

Joined Sep 9, 2010
17,496
Those solar lights you see everywhere, which can be obtained cheaply of free, all use a simple boost circuit to light an LED from a single AA or AAA cell. If you supply one 3V, it'll easily give you 6V or more. Maybe that's all you need?
 

JMac3108

Joined Aug 16, 2010
348
I would look for one of those switching dc/dc boosters. They are much more efficient then most of the linear boosters.
There is no such thing as a linear boost. All boost circuits require some sort of switching. If there is a linear boost that I'm not aware of, please post it and enlighten me :)
 

chunkmartinez

Joined Jan 6, 2007
180
There is no such thing as a linear boost. All boost circuits require some sort of switching. If there is a linear boost that I'm not aware of, please post it and enlighten me :)
They are called linear, reguardless which is why I called them that. Anyway, if they do require switching, where are the components like inductor, inside? And why are they so inefficient?
 

ErnieM

Joined Apr 24, 2011
8,377
Linear, schminear. I suggested a good and proper solution using a grand total of three components, by the way none of which is an inductor.

Anyone have anything simpler?
 

JMac3108

Joined Aug 16, 2010
348
They are called linear, reguardless which is why I called them that. Anyway, if they do require switching, where are the components like inductor, inside? And why are they so inefficient?
Can you post a link to some type of boost that calls itself linear? I'd like to see it for my own education in case this ever comes up again. Thanks.
 

JMac3108

Joined Aug 16, 2010
348
To your efficiency question ...

First off there is no such thing as a linear boost, so lets forget that and assume you're just generally asking about switching power suppy efficiency.

A typical swithcing power supply can be 85% efficient, some better, some worse. This is quite good compared to a linear supply. Lets take a simple example of a linear regulator converting 12V to 5V with a 100mA load. THe efficiency is Pout/Pin = (5V)(100mA)/(12V)(500mA) = 5V/12V = 0.42 or 42% efficiency. This is pretty bad compared to a typical 85% in a switcher!
 
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