ksp13/14 instead of MPSW45A Darlington transistor?

[m0zeid]

Hello everyone,

This is my first post here, and my first electronics project, so take it easy one me plz .

I want to built an amp an decided to go low profile and do a simple one. So I followed this:

sci-toys.com/scitoys/scitoys/computers/solderless/amplifier.html

I went to the electronic parts shop and bought every thing except the transistor.
It wasn't availble but the guy told me to take ksp13/14 it's has less power but it works.

Is this true? can it work with the same original circuit?

Because I already did the circuit but it's not working, wondering what the problem is!!

Sorry for the relatively long post

 

[jerluwoo]

If your building http://sci-toys.com/scitoys/scitoys/computers/solderless/1_watt_audio_amplifier.jpg I couldn't imagine it working correctly at all let alone providing the claimed 1 watt.

 

[VibroKing$]

MPSW45A (ic 1A Pd 1W) ---> KSP13/14 (.5A .5W)
with 9V and 50Ohms resistor Icmax = 0.18A Pmax = .405W
it works but with a 8ohm speaker most of power is dissipated on collector resistor (50Ohms)
for best results you should use a 50 or 100 ohms speaker and remove resistor.

 

[m0zeid]

thanks guys for the great help.

First i will try replacing the 50 resistor with a lower one. If that doesn't work I will try something else, maybe based on LM386 since there is a lot of projects about it floating online.

I don't think that i can find a speaker with that high impedance.

Will post about the results soon.