single transistor speaker amplifier

Thread Starter

Research Survey

Joined Feb 27, 2016
can you guys please help me build a simple transistor audio amp like the following

or this

i try the following circuit but there is no output.

my only available materials are

bc 548b transistor
4 ohm 0.5w speaker or d24mm Piezo Transducer
i know i need to consult the datasheet to solve for the base collector emitter parameters but i dont know how.

my source is a frequency generator using 555timer ic with potentiometer varying the frequency
pin output from ic is around 20 -25ma max

my desired output is something like this

hoping someone can teach me how to make one and how to compute one

many thanks in advance.