Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Curves on the datasheet of the LM386 amplifier show that it works fairly well driving an 8 ohms speaker but instead of double the power into a 4 ohms speaker, the amplifier wastes much more battery power (by heating) when driving a 4 ohms speaker than double the heating of when driving an 8 ohms...
Some "ultrasonic" pest repellers do not produce ultrasonics because they are fake and since buyers cannot hear ultrasonics then they do not know they are fake and without any ultrasonics.
Can pests hear ultrasonics and if they do hear it are they repelled by it? Maybe not.
There are new Chinese no-namebrand 9V Lithium rechargeable batteries (charged from 5V USB) available at VERY low prices. no specs, I do not recommend them.
A 9V alkaline battery produces a low continuous power. Then an ultrasonic producer will not be loud enough to shoo pests away. A pest that hears one ignors it. About 40 years ago the US government fined companies who made ultrasonic repellers for false advertising. Ask Google if ultrasonic pest...
At the same loudness, the cheap TPA3116 amplifier sounds the same as the powerful Pioneer amplifier because your hearing has an average normal loss at high frequencies (distortion) if you are a male who is older than 15 years old. At 35 years old the sounds are as muffled as an old AM radio or...
An audio amplifier always has its distortion mentioned in its output power rating. This cheap amplifier does not say its distortion which is probably massive.
Is its output power 100 Whats or is it 100 Watts? It says its Maximum power is 100W but Maximum power is peak power.
Peak power is double...
Each of my hearing aids has four microphones for directionality, left, right, front and back. The earphones do not have front and back but somehow I can hear front and back directions. Most of the time, the directionality keeps the mic with the loudest voices turned on and the other mics turned...
If you cannot hear birds then you also probably cannot hear an old phone ringing or hear a fire or CO alarm (like me without my hearing aids). You need a high frequencies boost.
If the earphones are vented then the high frequencies boost will probably produce feedback.
My hearing aids have...
My LM386 circuit is the same as your circuit except pin 1 and pin 8 have gain boost parts added. Try using 47 ohms for a gain of about 340 times.
Since you have high frequency hearing loss then the amplifier might be clipping at low frequencies.
Most deaf people have "normal for their age" high frequency hearing loss. My hearing aids boost high audio frequencies twice as much as a treble tone control that is at maximum.
The sensitivity for your electret mic and preamp is normal for a microphone in your hand in front of your mouth but...
That very old circuit design was recently copied by the Chinese. It never produced an output of 30VDC at 3A because it always had overloaded parts and had too much voltage and current losses. If you increase the output current then you increase the overloading, increase the losses and cause the...
With a 5V supply and a 10k biasing resistor, many electret mics will not work properly.
Most electret mics use a 2V minimum supply and draw 0.5mA max. Then the electret mic gets 5V - (10k x 0.5mA)= 0V.
Using a 4.7k resistor with the 5V supply, the mic gets 2.65V and works fine.
I use a 10k...
All modern solar garden lights use the solar panel to turn them on and off because the old photocells got sunburned then soon failed.
You will need a huge, expensive solar panel and battery to produce enough power for a street light.
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