You finished an audio circuit. But the sound is too weak.
Many people use LM386 to increase sound up to a speaker. Why should you do it too? Some said to try it now.
But…it is better. If you read LM386 Datasheet before.
LM386 is a low voltage audio amplifier. And, good at working with a battery. Its shape is similar for IC-741, DIP-8. So, small and easy. Even small but great sound.
Cr: LM386 of National Semiconductor. I like it.
Often we use LM386 in DIP-8. Which there are a few pin connections. Even other packets are the same. For example, SOP-8, TSSOP-8, etc.
See LM386 Features
- Give enough power—Common Power of the output is about 700mW at VS=9V, RL=8Ω, THD=10%. Imagine you can listen to soft music at prefer corner.
- Use Wide supply voltage range of 4V to 15V.
- Use low supply current—if no input signal is approx 4mA or max 8mA.
- Internal voltage gain set to 20 or 26dB. (without other parts)
- The more voltage gain to 200 or 46dB. When we connect a 10uF capacitor across pin 1(+) and pin 8(-).
- And, we may use a resistor in series with the capacitor. To reduce the gain between 20 and 200.
- Low harmonic distortion: 0.2% typical
- Frequency bandwidth: 300kHz in typical
With a lot of their benefits. A lot of electronic appliances have it to drive the speakers. Example for, radio, MP3 player, Mini Portable speaker, Etc.
More circuit more understand
My brain is slow. I cannot understand any information fast. Has this happened to you?
I have used images. They help me understand anything more.
Also, I like the circuit diagram and circuits. I see and learn and get many ideas from it.
So, let’s see more LM386 circuits.
The smallest amplifier gives a gain of 20 with the least parts.
It is true. It is an amplifier circuit. Even there are one IC and one capacitor only.
And, It uses low current at the output.
But In real usage. You need a louder of sound. How do you do? You can do it in a simple way. Below.
X200 great small amplifier
In the circuit. The gain of circuit rise up to 200. Because we place the Capacitor-C2 to the IC. Connect the positive leg of C2 to Pin 1. And, the negative leg to Pin 8.
But sometimes high gain is not good for us. We can do too.
X50 lower gain of LM386 amplifier
We add another one resistor-R2 in series with C2. To reduce the gain to 50.
LM386 Amplifier with bass boost
Sometimes you may want a special bass. We also can do. Easy…with adding one resistor and one capacitor only. See in the circuit. The R2 connects with C2 in series.
This circuit is a bass booster. The output gain depends on a bass frequency. For example, Gain 25dB: 100Hz, and Gain 19dB: 2kHz.
Almost forgot some components on every amplifier above have important.
- We can adjust the volume by VR1.
- Both R1 and C3 will keep a good sound. They improve a high-frequency load for stability.
Do you know we can do other circuits with LM386?
LM386 Square wave oscillator
We will see a square wave oscillator circuit. Also, we can create it is audible alarms on the speaker. Because this IC is on type of the op-amp. It is good at doing oscillator well.
The output frequency is approx 1KHz. We can change C2. More capacitance to less frequency.
More LM386 projects
You begin to be interested in them. Of course, Doing is good learning. See more.
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