Dc to AC Konverter

Parts List:
 R1 = 10K
 R2 = 100K
 R3 = 100 ohm
 R4 = 50K potmeter, Linear
C1,C2 = 0.1uF
 C3 = 0.01uF
 C4 = 2700uF
 Q1 = TIP41A, NPN, or equivalent
 Q2 = TIP42A, PNP, or equivalent
 L1 = 1uH
 T1 = Filament transformer, your choice