Analogue Active Noise Cancellation Headphones

You may use try this circuit :



For adjust Vsupply form power supply.

BradtheRad said:

This should be a duplicate of the last stage of your layout.



This simulator (www.falstad.com/circuit) does not show supply leads. It only has a setting for output V min and max. The output occupies the same range as if supply leads were shown.

I wonder about your supply V settings at the third op amp.

Did you try various high and low input levels? At both potentiometers?

Something should have worked. You should have seen some signal from the output.

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This should be a duplicate of the last stage of your layout.



This simulator (www.falstad.com/circuit) does not show supply leads. It only has a setting for output V min and max. The output occupies the same range as if supply leads were shown.

I wonder about your supply V settings at the third op amp.

Did you try various high and low input levels? At both potentiometers?

Something should have worked. You should have seen some signal from the output.

Click to expand...

hello !
have a good day ahead
i have patched that circuit on bread board and getting expected and required results..
for this circuit i have used Sinusoidal wave as a input from function generator..
but now i have to replace this input with an audio signal.. so i tried to give a tone signal from laptop to bread board through audio stereo cable from the jack of laptop.. but i could't get output after 1st stage(amplifying stage)
while when i directly connect the output of audio stereo cable to Oscilloscope it shows a sinusoidal wave with 2 Volt peak-peak amplitude..
in short breadboard circuit is processing simple sinusoidal signal but not an audio tone signal.. so what i do??
regards
Fleming

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BradtheRad said:

You need to plug a stereo patch cable into your computer. A common type is the 1/8 inch 'mini' size.

Typical cable like you would buy at the store for a few dollars. (Or on Ebay.)

Or identical plug at both ends:

The other end can go to a matching mini jack, installed in your project enclosure. Then connect wires from the jack to your circuit board.

Or if you would rather make a permanent connection, just clip the plug(s) off one end, run the cable into your enclosure, and solder the wires directly to your circuit board.

Click to expand...

hello !
have a good day ahead
i have patched that circuit on bread board and getting expected and required results..
for this circuit i have used Sinusoidal wave as a input from function generator..
but now i have to replace this input with an audio signal.. so i tried to give a tone signal from laptop to bread board through audio stereo cable from the jack of laptop.. but i could't get output after 1st stage(amplifying stage)
while when i directly connect the output of audio stereo cable to Oscilloscope it shows a sinusoidal wave with 2 Volt peak-peak amplitude..
in short breadboard circuit is processing simple sinusoidal signal but not an audio tone signal.. so what i do??
regards
Fleming

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arunava7 said:

Well, before any further discussion, why would you like to implement it using MCU? I lost my interest in the project coz it actually is much better in its analog form, also its digital version will need more processing power.

Click to expand...

hello !
have a good day ahead
i have patched that circuit on bread board and getting expected and required results..
for this circuit i have used Sinusoidal wave as a input from function generator..
but now i have to replace this input with an audio signal.. so i tried to give a tone signal from laptop to bread board through audio stereo cable from the jack of laptop.. but i could't get output after 1st stage(amplifying stage)
while when i directly connect the output of audio stereo cable to Oscilloscope it shows a sinusoidal wave with 2 Volt peak-peak amplitude..
in short breadboard circuit is processing simple sinusoidal signal but not an audio tone signal.. so what i do??
regards
Fleming

You must design new value of resistor to your circuit ,step by step, by using formular form circuit analysis not only approximated value because such a ideal model of Opamps used

(refer to books your bookshelf). What is impedance of audio stereo cable ? You know this ?

Ask your self, How to check that impedance of headphone ? I think from output 2 Volts peak-peak above refered by you , you can use the voltage divider method to find the

impedance at output branch of your circuit. And should read my above old hints again.


That is the basic analysis but may hard for newbie like other subjects to familiar and study all thing that you can think/find !!!!!!!!!


Happy ;-)

phongphanp said:

You must design new value of resistor to your circuit ,step by step, by using formular form circuit analysis not only approximated value because such a ideal model of Opamps used

(refer to books your bookshelf). What is impedance of audio stereo cable ? You know this ?

Ask your self, How to check that impedance of headphone ? I think from output 2 Volts peak-peak above refered by you , you can use the voltage divider method to find the

impedance at output branch of your circuit. And should read my above old hints again.


That is the basic analysis but may hard for newbie like other subjects to familiar and study all thing that you can think/find !!!!!!!!!


Happy ;-)

Click to expand...

its all fine.. but point is, either i must have to use a jack sort of thing to make connection with bread board..??? if so then which jack i have to use?? or i use audio line cable directly connected to breadboard.?

A stereo 'mini' (1/8 inch) jack is typical.



Though you may be able to attach alligator clip leads to the barrel rings on the plug...
it is all too easy for them to slip, causing crackling in your ears, or a short circuit, etc.

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A stereo 'mini' (1/8 inch) jack is typical.



Though you may be able to attach alligator clip leads to the barrel rings on the plug...
it is all too easy for them to slip, causing crackling in your ears, or a short circuit, etc.

BradtheRad said:

A stereo 'mini' (1/8 inch) jack is typical.

Though you may be able to attach alligator clip leads to the barrel rings on the plug...
it is all too easy for them to slip, causing crackling in your ears, or a short circuit, etc.

- - - Updated - - -

A stereo 'mini' (1/8 inch) jack is typical.

Though you may be able to attach alligator clip leads to the barrel rings on the plug...
it is all too easy for them to slip, causing crackling in your ears, or a short circuit, etc.

Click to expand...

good !
but it has 5 pins.. so what is its pin configuration??

As it stands, you'll use only 3 terminals: Left ch., right ch., ground.

The other two pins are for external speakers. They disconnect when you insert the headphone plug. (You can spot the springy clips in the righthand image.)

Typical schematic:



- - - Updated - - -

As it stands, you'll use only 3 terminals: Left ch., right ch., ground.

The other two pins are for external speakers. They disconnect when you insert the headphone plug. (You can spot the springy clips in the righthand image.)

Typical schematic:

BradtheRad said:

As it stands, you'll use only 3 terminals: Left ch., right ch., ground.

The other two pins are for external speakers. They disconnect when you insert the headphone plug. (You can spot the springy clips in the righthand image.)

Typical schematic:

- - - Updated - - -

As it stands, you'll use only 3 terminals: Left ch., right ch., ground.

The other two pins are for external speakers. They disconnect when you insert the headphone plug. (You can spot the springy clips in the righthand image.)

Typical schematic:

Click to expand...

have a good day ahead !
how i have to connect this active noise cancellation circuit with headphones..??
i am bit confused about this..
so kindly guide me
Fleming

Try to use Monte Carlo Analysis for adjust your circuit but this function I had found on Pspice program.




The route to be professional has science , but Engineering tend to imitate world.

phongphanp said:

Try to use Monte Carlo Analysis for adjust your circuit but this function I had found on Pspice program.




The route to be professional has science , but Engineering tend to imitate world.

Click to expand...

oh nope i am talking about its implementation in real life.. how i have to connect this ANC circuit with headphones..?? how i gave input.? how i take out put??

That's mechanics work , your ANC component be solution of the drop voltage error ? But if you try add ANC spice model to simulation of full system , it's not better ?
And in Pspice program , you can find such a model , I think . But depend on What's requirement quality of your work .

In production process , There're optimizing process could you find it on commercial mechanics part like tunning and , long time ago , software process has meet The standard one.

phongphanp said:

That's mechanics work , your ANC component be solution of the drop voltage error ? But if you try add ANC spice model to simulation of full system , it's not better ?
And in Pspice program , you can find such a model , I think . But depend on What's requirement quality of your work .

In production process , There're optimizing process could you find it on commercial mechanics part like tunning and , long time ago , software process has meet The standard one.

Click to expand...

dear you still dont understand
actually its my project to design active noise cancellor headhones.. so i have implemented above mentioned circuit on breadboard.. but now i'have to connect this circuit with headphones.. and to take input signals(noise) i ll use micro phones.. so i am confused how to connect all these stuff

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phongphanp said:

That's mechanics work , your ANC component be solution of the drop voltage error ? But if you try add ANC spice model to simulation of full system , it's not better ?
And in Pspice program , you can find such a model , I think . But depend on What's requirement quality of your work .

In production process , There're optimizing process could you find it on commercial mechanics part like tunning and , long time ago , software process has meet The standard one.

Click to expand...

dear you still dont understand
actually its my project to design active noise cancellor headhones.. so i have implemented above mentioned circuit on breadboard.. but now i'have to connect this circuit with headphones.. and to take input signals(noise) i ll use micro phones.. so i am confused how to connect all these stuff

Implement the circuit on veroboard. Take out and give the signals from/to it as necessary using the stereo jacks and all.

https://www.google.co.th/search?hl=..._cp.r_qf.&fp=b5bb1c82f21b0af&biw=1600&bih=739

Read Turtorial Optimizing a Design (Passive Terminator) on The book "Microsim Pspice Optimizer" Analog Performance Optimization Software Page 5-1. And I have plan to design Microstrip antena of RFID system by this electronics software,also.

arunava7 said:

Implement the circuit on veroboard. Take out and give the signals from/to it as necessary using the stereo jacks and all.

Click to expand...

arunava7 said:

Implement the circuit on veroboard. Take out and give the signals from/to it as necessary using the stereo jacks and all.
what should be the block diagram of active noise cancellation headphones?? it should be either like this
or like this ??

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phongphanp said:

https://www.google.co.th/search?hl=..._cp.r_qf.&fp=b5bb1c82f21b0af&biw=1600&bih=739

Read Turtorial Optimizing a Design (Passive Terminator) on The book "Microsim Pspice Optimizer" Analog Performance Optimization Software Page 5-1. And I have plan to design Microstrip antena of RFID system by this electronics software,also.

Click to expand...

what should be the block diagram of active noise cancellation headphones?? it should be either like this
or like this ??

- - - Updated - - -

BradtheRad said:

As it stands, you'll use only 3 terminals: Left ch., right ch., ground.

The other two pins are for external speakers. They disconnect when you insert the headphone plug. (You can spot the springy clips in the righthand image.)

Typical schematic:

- - - Updated - - -

As it stands, you'll use only 3 terminals: Left ch., right ch., ground.

The other two pins are for external speakers. They disconnect when you insert the headphone plug. (You can spot the springy clips in the righthand image.)

Typical schematic:

Click to expand...

what should be the block diagram of active noise cancellation headphones?? it should be either like this
or like this ??

Click to expand...

1.

what should be the block diagram of active noise cancellation headphones??

Click to expand...

Your first diagram is better. Furthermore the ambient noise goes directly to your ears, rather than going through circuitry.

Therefore the ambient noise arrow should be transferred to the extreme right.

2.

Although the noise can be (1) amplified, and (2) inverted, by a single op amp...
and your second diagram appears to represent an inverting op amp...

The inversion function is distinct from the amplification function, and both are necessary. Therefore your first block diagram conveys the concept more correctly.

BradtheRad said:

1.



Your first diagram is better. Furthermore the ambient noise goes directly to your ears, rather than going through circuitry.

Therefore the ambient noise arrow should be transferred to the extreme right.

2.

Although the noise can be (1) amplified, and (2) inverted, by a single op amp...
and your second diagram appears to represent an inverting op amp...

The inversion function is distinct from the amplification function, and both are necessary. Therefore your first block diagram conveys the concept more correctly.

Click to expand...

if my first diagram is correct, then it means i have to use 4 micro phones.. but in market available noise cancelling headphones, only 2 microphones are used.. then how first diagram could be correct..??

I'm afraid I don't know the science of how many microphones to use, or exactly where to position them.

Initially I thought one mic would be sufficient at each ear. I thought it should not be within the earpiece compartment, but outside. I guess I was wrong.

As for your block diagram, it should also show the mic, speaker, and ear. That way the entire theory of operation can be grasped quickly.

If you can assemble this project, and make the noise cancellation work, then you will know more about it than I and a lot of other people.

BradtheRad said:

I'm afraid I don't know the science of how many microphones to use, or exactly where to position them.

Initially I thought one mic would be sufficient at each ear. I thought it should not be within the earpiece compartment, but outside. I guess I was wrong.

As for your block diagram, it should also show the mic, speaker, and ear. That way the entire theory of operation can be grasped quickly.

If you can assemble this project, and make the noise cancellation work, then you will know more about it than I and a lot of other people.

Click to expand...

https://electronics.howstuffworks.com/gadgets/audio-music/noise-canceling-headphone3.htm
this is how ANC headphones work
what you ll suggest me now ?

Are you really sure the 1st diagram is correct? If it is, the noise gets amplified and inverted, while the ambient noise is not amplified...how will they cancel each other with different amplitudes.

Ambient sound wave(noise) is electronically inverted, and the produced counter wave cancel out the noise wave when you add them.