Design of 3W simple OCL power amplifier circuit composed of LM386

　　This circuit is an OCL power amplifier circuit composed of low-power integrated power amplifier LM386. The circuit structure is simple and easy to debug, making it very suitable for self-production.

　　Working principle of the circuit: IC1 and IC2 in the figure are two integrated amplifiers LM386, connected into an OCL circuit. C1 plays the role of power supply filtering and decoupling, C3 is an input coupling capacitor, R1 and C2 play the role of preventing the circuit from self-excitation, and RP is a static balance adjustment potentiometer. IC1 and IC2 use the integrated amplifier circuit LM386, which has the characteristics of low power consumption, wide voltage adaptation range, wide frequency response range and few peripheral components. Its working voltage is 4V~16V. When the working voltage is 6V in the figure, the rated output power can reach 3W, which is suitable for driving small speakers or as a voice prompt and alarm amplifier for equipment. Resistor R uses a 1/2W metal film resistor. Capacitor C1 uses an aluminum electrolytic capacitor with a withstand voltage of 16V; C2 uses a polypropylene capacitor, and C3 uses a tantalum electrolytic capacitor. RP uses an organic solid core potentiometer. Speaker BL uses an 8Ω speaker or speaker with a rated power of less than 10W according to actual needs.

　　Production and debugging method: After the circuit is installed, ground the audio signal input terminal and adjust RP to make the DC voltage output of the two 5-pin IC1 and IC2 equal. Since LM386 has few external components, it can work normally under normal circumstances. The circuit can be installed on a homemade printed circuit board or soldered on a universal printed circuit board.