Rechargable pocket sized amplifier

In this instructable I gonna try to describe how to make a simple rechargable pocket sized amplifier.
It's works using only two low power transistors and two nickel metal hydride batteries (Ni / MH).
The case is made with 3mm cardboard for making it as light as posible.
Ps: I'm from Argentina so let me know for any grammar mistake

Step 1 Materials

For the case:
A piece of 3mm cardboard
A cutter
Some glue
Screws
Separators

For the circuit:
R1= 4k7 resisor ( yellow violet red)
R2= 1M resistor (brown black green)
Q1= BC548 or 2N3904
Q2=BC327 or 2N3906
C1= 10uF capacitor
2 AAA batteries

Extras:
A batteries charger
A wire for connecting the amplifier to the sound source
A wire for connecting the amplifier to its charger

Comments

[Tyto Productions]

What kind of speaker did you use? It looks like a computer speaker. Would any speaker work?

[lukeD]

great ible *5

Can I hook up 5 big speakers to this amplifier?

[schumi23]

Great ible!
"Ps: I'm from Argentina so let me know for any grammar mistake"
Well, i only found one:
It would be more proper to say "Let me know about any grammar"
Ive been looking for an ible like this all over instructables, and have finally found it thanks to you:) Thanks!

[usbg3rd]

it is not properly biased it clips the portion of the audio signal (negative crust)

[usbg3rd]

hello
can u please tell me what is the output power of the amp ???

[Mr Sinster]

http://www.instructables.com/id/Yet-Another-Pocket-Size-Altoids-Speaker/

hey i was able to make your project!

[wunderdog317]

in step 7 what was that thing not the walkman

[ecopp96]

que tengo que hacer para conectarlo a 12 volts?? Me encanta este proyecto, lo hice pero tiene mucha interferencia y quisiera uasrlo en el auto pero con el encendedor del mismo que tiene 12 volts. Saludos y gracias por el circuito. :)

[brunoip]

En ese aso tenes que reducir la tension, proba conun lm317. Saludos

[ecopp96]

hay alguna manera de reducir la interferencia porque si no hay musica me capta la radio. Gracias por responder tan rapido.

[brunoip]

Usaste cable mallado para conectar el amplificador a la fuente de sonido?

[ecopp96]

no, use cable comun. puede ser eso lo checare. Gracas por el consejo.

[ecopp96]

cambie los cables yy elimine algunas conexiones que habia en el medio del cable de empalmes que hice. Lo conecte con transformador de celular que da entre 4.5 y 9.5 volts y 8000ma y la interferencia se fue que podra ser?

[brunoip]

Los cables si usas un solo tramo de cable mallado para la entrada reducis mucho el ruido. De fuente si usas una de celular de buena calidad y 4.5 volts seguro va a estar bien filtrada y tambien te reduce los ruidos. Saludos

[mgingerich]

Does it matter what kind of transistor as long as you use NPN?

[tobster9103]

one of them is a NPN and the other is a PNP. It does matter. Q1 is NPN and Q2 is the PNP, you can tell from the schematic. Hope this helps out.

[blinkyblinky]

I love it.

[dannyo013]

I was wondering if there is a way to make this with a 1/4" input jack for electric guitars. Would make a great portable amp.

[-Syrus-]

How 'bout just adding a 1/4 jack and trying it out?

Dunno about the input impedance...But try it :P

If you are smart you might wanna build something like:
http://runoffgroove.com/littlegem.html

Easy as pie

or

http://www.beavisaudio.com/projects/NoisyCricket/

Better version ! :P Props to Dano the designer.

These are all based upon the allmighty Smokey amp.
Maybe you should just buy one of those ;)

[robot1398]

but they need ic this dosent
so i prefer this one

[-Syrus-]

Then please, tell me what is wrong with using a IC?

OP-Amps circuit mostly use IC's for the bigger gain they can deliver.

LM386 is the most used audio amplifier in DIY and guitar effects.
Its reliable, sounds good and is easy to work with.( As in one chip and two capacitators is the bare minimum for a working guitar amp. eg Smokey amp by Zinky electronics)

So please don't give your opinion.

[plmqaz1243]

Wonderful world we live in, when people are shunned from giving their opinion by some guy who... I don't even know what you do. Great job.

The misspelled word of the day is:
Mispell

[sunnykhaskheli]

Hellow im new and 13 years old, so i dont know much about Q1 and Q2 whats the mean of this

[brunoip]

Q1 and Q2 are transistor, they amplify the signal in order to move the coil of the speaker.
It could be anything, in spanish we name the transistors with a "q"

[ajervis]

um can i use capicitors with different volts on a circuit?

[brunoip]

Yes, you can

[lokix86]

hey is it possible if i can change the female audio input and replace it with a male audio input? (like it is on regular in the shops speakers)

[David97]

How many whatts is the speeker?

[David97]

Built this in a few hours. If anyone is wondering the parts cost less than $5 (NZD) (not including batterys).

[ganibase]

It would be easyer to use TDA2822M then you can use 2 AAA rechargeable batteries and it would deliver up to 1W per channel at 10% THD

[robot1398]

some pics

[Biggimac]

Had to ask!
On your strip board, why did you put your components so far from each other?
They won't bite each other!!

[robot1398]

i know but i had of this size and that time i was not knowing how to cut a strip board

[phevtron]

ahm hallo, im new and 13 years old, so i dont know much about ufs and so on....... whats the diference between uf and μf ?

[Phoghat]

uf is the same, just written incorrectly. Means micro farads

[-Syrus-]

uf is how most people online write it, the correct and scientific way is μf.

It stands for micro Farad.

Micro is 1 x -10^6
Farad is in F and stands for capacitance.

[brunoip]

there is no difference.

[phevtron]

thnx :D :D

[yaly]

there is a circuit that i know but i don't know if it is going to work or not it uses only two transistors an npn and a pnp.

^
l
-------------------------O l------l
l----------l-------l l
-------------------------O l l
l------------------l l
GND l------l

the top one is the npn.

[sebastianvdm]

como conectas el cargador? la pata del medio es negativa o positiva?