Rechargable pocket sized amplifier

Step 3 Making the circuit

Is a really easy to do circuit.
First of all you gonna need to do the PCB.
You can do it with ironing method using the pdf or using the way that you allways use.
The PCB is designed for the BC transistors so if you what to use the 2n3904 and 2n3906 transistor be careful whith the terminals.

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

Amplifier circuit extracted from "Lupin, introduccion a la electronica".

Comments

[Begradoo]

I built this little amp and it works great considering its simplicity and low voltage. It drives cell phone speakers especially well.
Would it be possible to use a more robust set of transistors and higher uf caps and increase the voltage? Maybe drive a little bigger of a speaker.

[mamajr96]

How exactly do you make the PCB, understand you need to print the PDF, but what exactly do you do.

[lukeD]

great ible *5

Can I hook up 5 big speakers to this amplifier?

[blinkyblinky]

I love it.

[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

[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

[sebastianvdm]

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

[tux95]

when i put mine together the audio just comes out as scratching but in rythme to what ever song is playing.
would that be an issue with my connection?

[robot1398]

your some metarial should not be working properly
cap must be broken
or the transistor must be broken
check if any wires are short
R

[robot1398]

in the circuit digram what dose"in" mean
is it audio in

[brunoip]

What else could it be?
It is the audio input.
Regards, Bruno.

[robot1398]

thanks
good project

[955josiah]

if i use 4.5 volts of battery is there any possible to make it louder

[wobbler]

Great project! You could add a solar cell or two from a cheap garden light to the back and make it solar powered too.

[phevtron]

ahm sorry again but... i found a bc 548b and a bc 548c, can i use them ? does the b or c matter ?

[Lenny24]

The B and the C just stands for the Current gain.
B should be around 400 and the C around 500, i think.
Maybe, if you use the C-Type, it is a tiny bit louder, or so.

[brunoip]

it should be fine

[C_KNOW]

Hey Bru, dumb question, but working on this, my first project, need to know the bottom "wire" from power source to speaker is it connected to rest of the circuit by that inch long wire(because its missing a blob)? and also the "IN" that's the audio source correct? thanks for this can't wait to get it hooked up

[brunoip]

The negative of the power source, the negative of the imput and the negative of the speaker are conected together.
Put them in that way for testing.
Is that your question?
Regards, Bruno.

[C_KNOW]

Great exactly! Gracias

[coilsinamotor]

wow thats soo easy so easy that even i can do it thats for the instructable!

[pyrohaz]

If you put the resistor R2 between the transistors collector and base, you will most probably increase the sonic quality due to some negative feedback :) Also, it will help with biasing as battery decreases :D

[alex12349]

what is the battery usage pattern i mean how long one complete recharge lasts w/o any distortion?

[arvi9ster]

 will it work if i use 1bc transistor and the 2nd one the 2n3906?
i tried assembling it but nothing works!
could you suggest as to what the problem might be?
thankyou

[brunoip]

Try to get two bc.
Also note that the arrangement of the terminals is different.
Regards, Bruno

[pancho del rancho]

can u change the 10 uf to a higher 1 to make it louder if its possible at all

[brunoip]

It won't make it louder

[mynameishamm]

How many *WATTS

[pancho del rancho]

i think one the 5v is 3W and the other im not sure

[mynameishamm]

How many volts? SORRY for horrible english.

[pancho del rancho]

um 1 is 5 volts and other im sure is like 18

[tiekietemboe]

How big must the speaker be, and how much volts?

[brunoip]

30 mm diameter, 8 ohm, 0.25 watt, ¿volts?