Passive RC high pass filters

[nikaqim]

good video . thanks dude :D

[SuperOnionFruit]

THE LIKE TO DISLIKE RATIO IS INFINITYYYYYYYYYYYYYYYYYYYYYYY­YYYYYYYYYYYYYYYYYYYYYYYYYYYYYY­YYYYYYYYY

[mdesm2005]

If you only want to block the DC from being amplified, why not just use the capacitor? In other words, why not use a resistor of infinite value (open circuit)? I suppose you can hear below 15Hz, true, but it's still an extra component.

[isrxi]

BTW . Your videos help me alot ant make more of them ;] (sry for english)

[prab03]

you are awesome

[Poseidon99Jeus]

1 thing that I don't understand from the beginning of the video. If the voltage across the capacitor cannot instantaneously change, why for high frequency it acts like a short circuit. I means high frequency, there is a lot of alteration in the signal.

[andrewmoullas]

great videos, very educational !

looking forward for more videos.

thank you!

[jimfin12]

Fantastic videos.The best here.Definately.I would like to understand how you come up with a 20 mv p to p with the 9v and the 5000ohm resistor and what exactly constitutes a DC Bias and how is it made in a circuit.Cheers.

[deetoos]

AAwesome video G!!!!!



[philg24]

Very good!! Thank you! :)



[chengda85]

can anyone help? I know if a signal is at cutoff freq the output will be -3dB gain and 45 degree phase shift, but what if the signal is lower than cut off frequency, how do you know what the output will be?

[ascott51088]

Great videos. They're so clear! I wonder if you do video narration professionally.

I do have a novice question though. I just watched this and the low pass filter video but I don't really understand what you mean by avoiding overloading the microphone with a high resistance.

[thewii552]

why do you need a high pass filter to remove DC offset? you can do that with just a capacitor...???

[culerz]

how about band pass filters?

[lucasmontec]

Why did you put the 9V to the Mic to place the 20mV above a 9V dc and then used the low pass filter to remove it?

[RIAAagent47]

Can you use a potentiometer for the resister to adjust frequency???

[Afrotechmods]

@RIAAagent47 Sure!

[workwillfreeyou]

Thanks, How about P.W.M. / Variable Frequency Drives used on A.C. Induction Motors. My V.F.D. has voltage spikes above the voltage rating of the motors insulation. How should I size “Choke Coils “? 2 H.P. / 480 volt motor.

[FaradayToRemember]

@workwillfreeyou Sounds like the caps in your VFD are bad. Allen Bradley and GE both have service manuals online. GEs is at geindustrial dawt cawm. Often VFDs self-diagnose and they might catch it with an error code on the display. What maker/model is it?

[Nadrealis]

I have a question. Why do you have a 9 volt DC offset if you're only amplifying the 20mV input signal?

[FaradayToRemember]

@Nadrealis Because engineers arent taught to think any more and the ones that can get their talents wasted by being assigned to Six Sigma projects, EPA/FDA/OSHA regulations because the company is too cheap to hire people to do it, so engineers are formula/example drones and nothing gets done engineering-wise at their jobs. They do it because they were taught to do it, and all their textbooks say to do it, but all their school books reference each other, and nobody (but me, it seems) knows why.

[Nadrealis]

@FaradayToRemember So it's just become the norm to do this and when people do this it's just because they've been taught this way and noone ever questions it?

I seem to have opened a can of worms and it's quite interesting to hear this stuff.

[TheCrazyStudent]

These videos are great!! The way everything is being explained makes it easy to understand. Please continue making these awesome videos.

[PantsLaRue]

This is wonderful! The break down of each part of the circuit and its purpose is so incredibly helpful. Thank you afroman! Plz don't stop.

[reviathon360]

Or bandpass filters. That would be awsome!

[reviathon360]

Can you do a video explaining the highpass filter using the OPAMP?

[rong111y]

know anyhow to convert the voice signal from a microphone like the one in your video to Digital?

by the way, Love to watch your easy understanding tutorials, good work.

[eatmy6u11e7s]

youtube keeps telling me, your low pass filter video is "not available in my country" :-(

Did you put any copyrighted stuff in there?

[Afrotechmods]

@eatmy6u11e7s There are some 10 second clips of Pendulum - Slam but they totally fall under fair use so I dunno why they are blocking it.

[alitou001]

I enjoy these videos

[SharkyLV]

you are the best! you really help me with my course. thaankk youuu

[engelteir]

Great videos, if only i knew about how to pick the right resistor! :P

[Afrotechmods]

@engelteir Diagram out your voltage source, the source resistance, the filter resistance, and your load resistance, and think about them like a voltage divider. If your source can only supply a tiny amount of current (like a microphone) you should use a high value resistor. If you have a heavy load like an 8 ohm speaker, you could let that be the "resistor" and just add a suitable capacitor.

[acidzoodoo]

Keep up the good work!

[toffer1220]

I enjoyed watching all your videos and I must say that you've done a great job. very clear easy to understand and you make it so it's more exciting rather than boring.. I would like to request for more tutorials on designing and troubleshooting.

thanks in advance!

[hyperboogie]

Fantastic - very clear expanation

I have an additional question - doesn't the resistance of the load itself interact with the capacitor and also affects the cutoff frequency?

[Afrotechmods]

@hyperboogie Yes

[L00peey]

@Afrotechmods hey can you pls help me, i have speakers that are good quality, and im powering them with an amp but the amp doesent have any bass knobs. so i can only adjust the frequency on my equalizer on the pc. but i also have a sub. and if i turn down the low frequencies then that effects the sub. i need the low frequencies for the sub but i cant have it becasue of the speakers. so i need to get something that can cut frequencies from 0hz to 60hz so that it doesnt bottom out my bookshelfs.

[polo2936]

@L00peey Check this on google: "high pass filter rca"

[L00peey]

@Afrotechmods ive looked for high pass filters but the dont go down to that lvl. i dont really need bass on the bookshelfs, i just need deep voice and very high frequencies, so if u can find something that cuts of at the frequency that doesent effect the voice that would be great. thanks

[yrachmani]

keep it up good job

[Albinorama]

More!!! Thank you!.

[Bylga]

Shut up! You got me for free!

[WhoWantsSomeWaffles]

Thanks for the videos! I'm really learning a lot by them. Keep it up! :)

[voltarens]

thank you

[silverstream314]

I love these videos. Keep it up!

[GTXAbunada]

Great tutorials man keep it up. You can use active filters if you don't want to worry about loading effects (I think).

[Afrotechmods]

@GTXAbunada Yup. Op amps can act as buffers between stages, or you can build the filter right into the feedback loop.

[elgus]

i had one of those function generators at my school

[quirmche]

Boy, that beaver really took a pounding!

[MrLiquimatter]

3:46, "Shut up! You got me for free!"

[darkstar744]

Nice haha that's pretty crazy xD

[MrLiquimatter]

omg, TAHNK YOU!