Power Amplifier Based on LM391 Circuit

Here is a 35 Watt audio amplifier circuit based LM391 chip. The LM391 Audio Power Driver is designed to drive external Power Transistors in 10 to 100 watt power Amplifier designs. High power supply voltage operation and true high fidelity performance distinguish this IC. The LM391 is internally pro- tected for output faults and thermal overloads; circuitry pro- viding output Transistor protection is user programmable. By National Semiconductor

Rangkaian 35 Watt Power Amplifier
Based on LM391

 

The circuit was designed to drive the power transistors of a power amplifier that will produce a power output of 35 Watts. Inductor L1 is constituted by 20 coils of wire, with thickness 0.9mm, round resistor R16. Transistors Q3-4 should be placed on heatsink. If are used the Q3-4 in packing TIPxxxx they can be placed straight above in PCB. If however they are used transistor in packing TO-3, then it will be supposed they are connected with short cables in the corresponding places on PCB.

List componet of 35 Watts amplifier LM391 circuit

R1-3-5-8-10 = 1Kohm
R2-7-11     = 100Kohm
R4-6        = 4.7Kohm
R9-12       = 100ohm
R13         = 47Kohm
R14-15      = 0.15ohm 5W
R16         = 1ohm 2W carbon 5%
R17         = 10ohm 1W carbon 5% 
C1          = 2.2uF 63V
C2          = 4.7uF 25V
C3-17       = 47uF 63V
C4-8-9      = 1nF 100V MKT
C5          = 47nF 100V MKT
C6          = 22pF ceramic
C7-11-12-13 = 100nF 100V MKT
C10         = 22pF ceramic 
TR1         = 10K Trimmer
D1-2        = IN4002
IC1         = LM391
Q1          = BD139
Q2          = BD140
Q3          = TIP2955
Q4          = TIP3055
L1          = See text