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59 votes
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If we use potentiometers as volume controls, don't they waste electric power?

If you do this, then it will waste a lot of power: simulate this circuit – Schematic created using CircuitLab You'll also need a very large and heavy potentiometer because it will have to ...
JRE's user avatar
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38 votes
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What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?

A buzzer usually has an oscillating transistor circuit inside - to make the buzzing noise when voltage is applied, so it makes a tone. Applying voltage to a speaker will not make a tone, so you'd ...
Danny Staple's user avatar
31 votes

I've become an electrical conductor for my headphones... but how?

The "buzz" is almost certainly RF pickup. This can be the mains (low frequency, 50/60/100/120Hz, unlikely in this scenario given a phone is involved) or rectification of the carrier frequency of the ...
Tom Carpenter's user avatar
23 votes

Is there any way to measure sound intensity in decibels without using a microphone?

If your customers aren't electrical engineers, how would they tell a small microphone on your main circuit board from say an oscillator, opamp, or voltage regulator? So any customer that only buys ...
really not Constantine A. B.'s user avatar
17 votes

Voltage of sounds of MP3 files

Amplification It does not depend on the music file, but at the amplifier sending the music to a speaker, or to a headphone/earplug connector. Music file A music file only contains 'values', and ...
Michel Keijzers's user avatar
16 votes

Audio spectrum analysis: PC Software vs Hardware Spectrum Analyzer

The deciding factor between stand-alone analyzer or soundcard would be the frequencies you're interested in. I will record the sound it makes with a microphone (it sounds differently if it is ...
bobflux's user avatar
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14 votes

I've become an electrical conductor for my headphones... but how?

The main fact, in my opinion, is that noise is heard only in right channel. First thing comes to mind is issue with grounding. But then both channels would receive the noise. Second - the source of ...
Anonymous's user avatar
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13 votes

How can I make a reliable tick tock sound electro-mechanically?

If you want something simple, just send a pulse to a speaker. My ancient DIY Geiger counter basically did this. You won't have much control over the sound, but it may be sufficient for your needs. You ...
Mattman944's user avatar
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13 votes

How can I make a reliable tick tock sound electro-mechanically?

The obvious way is to use a large relay, and pulse it at 1 Hz. That said, I read Electro-mechanical relay durability curve and it caused me to fear that a relay probably wouldn't last. Especially a ...
vidarlo's user avatar
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12 votes
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Is there any way to measure sound intensity in decibels without using a microphone?

You need to improve the definition of your problem. Privacy Does that mean any talking is unintelligible? The fact that some sounds can be heard, at a specific time, even if they are unintelligible as ...
Neil_UK's user avatar
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11 votes

Why do different value capacitors and resistors sound different in same amplifier circuit?

The impedance (think of it as resistance) of a capacitor changes with the frequency of the signal passing through. The lower the frequency (bass sounds) the higher the impedance. The impedance of ...
JRE's user avatar
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11 votes

I've become an electrical conductor for my headphones... but how?

My guess is that there is a break in the insulation of the right earbud and that electrical hum from your body is flowing into the noise cancellation amplifier. Try wrapping the bud in cling film and ...
Jasen  Слава Україні's user avatar
11 votes
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Where does this decibel equation come from, why a factor of 20?

Sound power (\$P\$) is proportional to the sound intensity (\$I\$): $$ P = A\ I $$ where \$A\$ is the surface area. And sound intensity (\$I\$) is proportional to the square of sound pressure: $$ I = \...
Rohat Kılıç's user avatar
10 votes

What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?

When someone is "buzzed" into the house, its with a relay (electro-mechanical) sound-maker. A relay, wired as normally closed, but able to break the circuit, is a buzzer. simulate this circuit &...
analogsystemsrf's user avatar
10 votes

What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?

Traditionally a buzzer was a device designed to make noise. Traditionally it would have been an electromechanical device. It would typically be supplied with DC and the oscillations would have been ...
Peter Green's user avatar
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10 votes
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How to produce a middle C on intel 8080?

DCR C decrements the C register and sets flags; it does not affect the accumulator (aka A register). The only instruction in this sequence which affects the ...
Russell Borogove's user avatar
10 votes
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High pitch audio frequency measuring

Most common audio equipment is set to match human hearing, 20Hz to 20kHz is their operating range. So you want to measure ultrasound, If you want only to measure high frequencies, you can use a bat ...
Juan's user avatar
  • 1,158
10 votes

How can I make a reliable tick tock sound electro-mechanically?

WWV transmits a "ticking" sound as five cycles of a 1000 Hz sine wave. WWVH transmits a similar "ticking" sound as six cycles of a 1200 Hz sine wave. When reproduced linearly ...
glen_geek's user avatar
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9 votes
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Phantom Power supply for Electret mic

You have roughly the right idea, but you should use a resistor divider instead of a single resistor to bring down the voltage. With your setup, the microphone is still subjected to high voltage, ...
Olin Lathrop's user avatar
9 votes

Why does an electret not pick up sound?

The output amplitude is so low the MCU ADC can't measure anything except the DC bias voltage. Contrary to your assumption, there is no built-in op-amp in the mic capsule. You will need a suitable ...
Justme's user avatar
  • 159k
9 votes

Is there any way to measure sound intensity in decibels without using a microphone?

Any device or transducer that can convert sound to electrical signal is by definition a microphone. Even capacitors can exhibit microphonics and can ruin your signal by converting audio or mechanical ...
Justme's user avatar
  • 159k
8 votes
Accepted

How to Construct This Small, Simple Electronic Device?

Here you go.......... simulate this circuit – Schematic created using CircuitLab
Trevor_G's user avatar
  • 46.8k
8 votes

High pitch audio frequency measuring

By definition of the audio range for humans, beyond 20kHz is beyond audio. There are audio equipment designers such as Rupert Neve who believe the range could be wider, but this is not necessarily ...
Graham's user avatar
  • 6,200
7 votes
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Why place capacitors in front of the line to a (headphone) audio speaker?

The two large capacitors are acting as AC coupling capacitors. A capacitor in series with a signal acts as a high pass filter (if you're curious about that, look into the impedance model of capacitors)...
lemonlime's user avatar
  • 106
7 votes

Audio spectrum analysis: PC Software vs Hardware Spectrum Analyzer

I would personally recommend using a PC for several reasons. From a monetary stand point, if there is sufficient information currently to identify issues using a trained ear, there is no need for an ...
loudnoises's user avatar
  • 1,856
7 votes

I've become an electrical conductor for my headphones... but how?

If you have a multimeter available, you can put it into AC voltage measurement mode and try to measure between the different metallic objects. Note that you should only touch the objects with the ...
jpa's user avatar
  • 8,843
7 votes

If we use potentiometers as volume controls, don't they waste electric power?

\$\color{red}{\boxed{\text{Will it waste electrical energy?}}}\$ Potentiometers are variable resistors and resistors waste power: - $$P_{dissipation} = \dfrac{V_{applied}^2}{R}$$ Or $$P_{dissipation} ...
Andy aka's user avatar
  • 465k
7 votes

What is a modern 2SD669 transistor replacement?

The transistor isn't critical. A \$25\:\text{W}\$ output into \$8\:\Omega\$ means a peak \$Q_{415}\$ emitter current of \$\frac{20\:\text{V}}{8\:\Omega}=2.5\:\text{A}\$. (Resistive load assumption, ...
jonk's user avatar
  • 78.3k

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