LM386 Audio Amplifier Kit 102

Introduction

Welcome to the exciting world of Circuit Creations electronics kits. To assemble this kit you will need the following basic items:

·  25W to 40W soldering iron.

·  Rosin core flux solder.

·  Diagonal cutters.

·  Needle nose pliers.

The central component of this kit is the LM386 Audio Amplifier integrated circuit. This device works with ground referenced inputs while the output automatically biases to one half of the supply voltage. Low quiescent current makes the LM386 a good fit for battery operation. The Circuit Creations LM386 Audio Amplifier Kit 102 uses a standard configuration that allows for different gain settings, a wide supply voltage range, and volume control. Your imagination is the limit for what can be done with this kit.

Circuit Assembly

The parts list for the components that are included with Kit 102 is as follows:

Designator / Value / Assembly Features
U1 / LM386N-3 / Notch in package must match notch printed on the circuit board.
C1,C4,C5 / 10uF capacitor / Make sure + capacitor is the same as + on the circuit board.
C2 / 100uF capacitor / Make sure + capacitor is the same as + on the circuit board.
C3 / 0.01uF capacitor / Marked with 103
C6 / 220uF capacitor / Make sure + capacitor is the same as + on the circuit board.
C7 / 0.047uF capacitor / Marked with 473
R1 / 10.0K potentiometer
R2 / 1.2K resistor / Brown-Red-Red
R3 / 10 Ohm resistor / Brown-Black-Black
J1 / Phono Jack
J2 / RCA Jack
PCB1 / K102

The schematic shows the component connections. Be sure to pay attention to the markings on polarized components U1, C1, C2, and C4-C6.

See www.circuitcreations.com for general assembly helpful hints.

Operation

The internal gain of the LM386 is set to 20 and can be varied by an external resistor and capacitor on pins 1 and 8 of the LM386. The components included in the Circuit Creations LM386 Audio Amplifier kit allow for setting the gain to approximately 20, 50, or 200 as described in the notes on the schematic. The volume for the circuit is adjusted by varying potentiometer R1.

Connect a DC voltage, such as a power supply, battery, or Circuit Creations LM317 Power Supply Kit 101, between 4 Volts to 12 Volts to the VCC and GND inputs of J1. An audio input signal source such as a microphone, MP3 player, tuner, computer audio output, Circuit Creations 555 Timer Oscillator Kit 103, etc. is connected to the phono jack at J2. An 8 ohm speaker (not included) is driven by the output on the RCA jack at J3. See the LM386 datasheet at http://www.circuitcreations.com/Data_Sheets_And_Manuals.html for further information and application ideas. ENJOY!!

Schematic

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