I'm still plugging away trying to understand the theory and practice of transistors as amplifiers.
I can get a common emitter circuit to amplify the voltage from an LC resonant circuit, enough to drive headphones and pick up radio.
What I want to do now is create an emitter follower, which will allow me to drive a speaker from this source.
The voltage from my first transistor stage seems to be about 1Vpp from my scope readings.
The problem I have is understanding how to design my emitter follower to drive the speaker. I know the theory is to bias the base in order to supply a sufficient amperage to the emitter, but I don't know amps I should be aiming for - it's a 8ohm .5W small speaker.
Would anyone be able to show me a very basic set up where a emitter follower transistor arrangement can drive a small speaker like this from a 9v battery? Everything I can find on Google has loads of complicated bootstraps and feedback etc which make it hard to 'see' what is happening.
Does it matter what the current is coming out of my voltage amplifier (CE) or is it just the voltage that matters?
Thanks
I can get a common emitter circuit to amplify the voltage from an LC resonant circuit, enough to drive headphones and pick up radio.
What I want to do now is create an emitter follower, which will allow me to drive a speaker from this source.
The voltage from my first transistor stage seems to be about 1Vpp from my scope readings.
The problem I have is understanding how to design my emitter follower to drive the speaker. I know the theory is to bias the base in order to supply a sufficient amperage to the emitter, but I don't know amps I should be aiming for - it's a 8ohm .5W small speaker.
Would anyone be able to show me a very basic set up where a emitter follower transistor arrangement can drive a small speaker like this from a 9v battery? Everything I can find on Google has loads of complicated bootstraps and feedback etc which make it hard to 'see' what is happening.
Does it matter what the current is coming out of my voltage amplifier (CE) or is it just the voltage that matters?
Thanks