Low voltage bridge audio amplifier based on op amp IC LM386 (Low Voltage Audio Power Amplifier). Application of this circuit include AM-FM radio amplifiers, Portable tape player amplifiers, intercoms, TV sound systems, Line drivers Ultrasonic drivers, Small servo drivers Power converters. This circuit can be operated by battery power.
This Low voltage bridge audio amplifier circuit is for low voltage applications requiring high power outputs. Output power levels of 1.0 W into 4 ohm from 6 V-and 3.5 W into 8 ohm from 12 V are typical. Coupling capacitors are not necessary since the output dc levels will-be within a few tenths of a volt of each other. Where critical matching is required the 500 K potentiometer is added and adjusted for zero dc current flow through the load.
Parts list :
R1, R2, R3, R4 : 270 ohm
R5 : 2,7 ohm
VR1 : 10K
VR2 : 500K Variable
C1, C2 : 20uF
C3 : 0.05uF
C4 : 0.1uF
IC1, IC2 : LM386
Note :
Vs = 8V RL = 4 ohm Po = 1 W
Vs = 12V RL = 8 ohm Po = 3,5 W
