barfkoswil
New Member
I have been working through the projects in the book Make:Electronics by Charles Platt. Everything was going well until we used a PUT and a capacitor to make an LED flash and this to was ok. Then we are asked to repeat the circuit using a speaker instead of an LED but the sound is quiet so a 2N2222 transistor is used for amplification. Unlike the PUT where it's output goes directly through the speaker it now goes to the base of the transistor and the current drawn through the speaker is now direct from the battery via 100 ohm resistor. please can someone explain how the amplification happens?