DC 2 DC problem

[jarleiceman]

Hello
I'm a man from the Cold North...Norway, and I have a question about DC2DC... :
I shall use this in a set of active headphones..and there are a 1,5v AAA batery here, but the voltage is to low...I have to have at least 2v for it...(not more than 3,5v..)
and the current is less than 100 mA, so I wonder if you have a solution for my project:
with a small capasators diodes and resistor (at easy at is can be...) I dont want to use active compenents (like Op-Amps etc...)
mabe a dobler of the voltage how do I do it....(I see I can use a DC.DC boost converter), but I want too make it cheap and with as less components as posible....
senserly
jarleiceman

[vk6zgo]

Two AAA batteries in series gives you 3 volts.

[Skimask]

http://www.amazon.com/UltraFire-Rechargeable-Battery-CR10440-Lithium/dp/B0046R6TIU

[IanB]

there are a 1,5v AAA batery here, but the voltage is to low...I have to have at least 2v for it...(not more than 3,5v..)
and the current is less than 100 mA, so I wonder if you have a solution for my project:
with a small capasators diodes and resistor (at easy at is can be...) I dont want to use active compenents (like Op-Amps etc...)
mabe a dobler of the voltage how do I do it....(I see I can use a DC.DC boost converter), but I want too make it cheap and with as less components as posible....

Hmm...

Two AAA batteries in series gives you 3 volts.

...oh yes! What an idea!

Ask yourself, can you make a circuit with capacitors, diodes, resistors (and yes, transistors), that fits in a space smaller than an AAA battery?  Will it also be cheaper than an AAA battery? Fewer components than one AAA battery? More efficient than one AAA battery?

By Jove, I think I see the answer! The cheapest, simplest, most efficient voltage doubler is a second AAA battery! Two AAA batteries in series gives you exactly what you are looking for!

[peter.mitchell]

Two AAA batteries in series gives you 3 volts.

...oh yes! What an idea!

Ask yourself, can you make a circuit with capacitors, diodes, resistors (and yes, transistors), that fits in a space smaller than an AAA battery?  Will it also be cheaper than an AAA battery? Fewer components than one AAA battery? More efficient than one AAA battery?

By Jove, I think I see the answer! The cheapest, simplest, most efficient voltage doubler is a second AAA battery! Two AAA batteries in series gives you exactly what you are looking for!

A round of applause for this man!

I have to have at least 2v for it...(not more than 3,5v..)

How do you know not more than 3.5 just curious? If allowed more than 3.5, eg, 4.2, you could use a lithium 10440 cell.

[vk6zgo]

I kept reading & re-reading it to see if I'd missed something pertinent,but it seems just what it says---he wants to get around 3v with AAAs.

Hence my suggestion of two in series!

I've noticed a lot of people want to go for the most complex way of doing things,regardless of whether there is any advantage In doing so.

[jarleiceman]

Of course I'v think about 2 AAA...and get 3v...but there isnt PLACE..... O0
jarleiceman

[mariush]

I already gave you a solution, with that LT1037 ... with the SOIC version and smd inductor, diode and capacitors, you can fit in half the space of an aaa battery and it will basically be a few mm tall.

Here's the post: https://www.eevblog.com/forum/beginners/dc2dc-1-5v-to-2v/msg339940/#msg339940

Here's my project : a 9v battery replacement ... The LT1037 takes 1v-2.7v from the supercapacitor and makes ~5.7v for a multimeter with 9v battery holder (the meter says battery low at 5.5v).
You don't need the trimpot at the top, you can just use a fixed resistor to get your voltage, i wanted to be able to adjust it. You can also move to everything surface mount and basically get it to use much less space.  I went with prototyping board and all through hole :

 

[jarleiceman]

Yes Mariush, I'm goinig for the LT1037...thank you for the serios and good answer, just what I was loocking for

[TheBorg]

Yes Mariush, I'm goinig for the LT1037...thank you for the serios and good answer, just what I was loocking for

What type of headphones is it? I'm sure if they left place for a replaceable battery they would've made it easy enough to find an actual replacement.

[vk6zgo]

Yes Mariush, I'm goinig for the LT1037...thank you for the serios and good answer, just what I was loocking for

Well,had we known you had two threads running,it might have helped.
You also appeared to be have limited knowledge.

I'm still very dubious-----the volume of an AAA is very small.& really small inductors are not very efficient.

You gave the impression that you were quite restricted in what you could easily obtain,but if you can get the LT1037 & stuff like that,you could also use Skimask's suggestion with one or two series diodes to reduce the voltage to your requirement.

[jarleiceman]

Thanks guys
You say: "You also appeared to be have limited knowledge"...
I'not...my English isnt very good..but I have a very good eduqation in data- & Electronics, and then I have been a high school teacher on  in Data- & elecronics for about 10 years,  but then I had a strooke (brain) and i'm working hard too come back...but I know my way around electronic, but as I sayed it been some years seence I practice.....and yes the simplest soloution is Skimask's  suggestion with one or two series diodes to reduce the voltage...And its BOSE Comfort Quite 15 headset...they doesnt work With only 1 AA (1,5v) any moore...but if I increase the voltage to 2.3---3..V it kick in and work, and the LED  (Power on) lights up....??    
jarleiceman

[jabramo]

Have you tried hunting down the root cause in the headphones circuitry?

If you want to go with a 2 AAA maybe you could consider something like this http://thumbs1.ebaystatic.com/d/l225/m/mIxtcSIBL1P2cvP50B50Dtw.jpg
Just attach that to the headband and solder the wire's to the terminals of the battery holder.

EDIT: Here is the battery terminal for the headphones

[jarleiceman]

Thanks 2 U all
It was actually Place for a AAA inside (dont know if it effects the sound...)and I serial conected them, a litle super-glue...worked like a charme....
but I give my left arm for the schematics for these.....

[djococaud]

Hi,
What about a small joule thief Psu ?
I've played with these and I know they can be very small...
I've used it to power leds goggles with an old "dead" AAA battery, very tiny and works like a charm !
If you want a clean output, just add a capacitor on the output...

[TheBorg]

Thanks 2 U all
It was actually Place for a AAA inside (dont know if it effects the sound...)and I serial conected them, a litle super-glue...worked like a charme....
but I give my left arm for the schematics for these.....

Can't do much worse than this