I'm trying to build a little speaker the takes input from a 1/8" headphone jack. My components are the audio jack (to take input from an iPod), a AA battery holder to hold 2 AAs, an on/off switch, a pot to control volume, two speakers, and an NPN transistor for amplification. My original circuit basically just had the audio input hooked up to the collector of the transistor, the 3v (from the AA batteries) hooked up to the base of the transistor, and the speaker hooked up to the emmitter; thus the audio signal would be amplified by the two batteries and sent to the speaker. Obviously this wont work because I need two grounds (one for the battery and one for the audio in) but have only one source. How could I make a circuit that amplifies the signal and goes to the battery ground and audio ground?
On another note, how could you determine the emmitter current from the base and collector current? say I have a collector current of 3 amps and a base current of 2 amps, would the emmitter current be 6? (3 x 2).
On another note, how could you determine the emmitter current from the base and collector current? say I have a collector current of 3 amps and a base current of 2 amps, would the emmitter current be 6? (3 x 2).