A great video that is easy to understand. It has helped me tremendously. Please continue to put out great content like this. No one else puts out this type of content that is down to earth and easy to understand.
I went through the same thing as you, trying to learn it myself. That's one of the things I'm trying to do with my channel: "I scoured the Internet for crumbs so you don't have to." Glad it helped.
Normally, I don't comment on YT Video's. But your video's are finally giving me deeper understandings in how electronics in general work. The way that you use to describe things is so easy but yet so detailed. Please continue with making these videos!! Greetings from the Netherlands ;)
Hey man. Just wanted to say. I'm an B1 aircraft engineer (B1 = Mechanical) who was wanting to change his discipline to B2 ( B2 = electrical) and have been studying for weeks preparing for my exam and have been wondering for a solid 3 hours now how on earth a transistor works on the negative half wave of the AC waveform. I scoured the internet and past papers and study materials for 3 hours until now 2am. And lo and behold. All it took was 1 min and 1 second into your video to simply explain exactly what i needed to know. You bias the signal by shifting it up to a positive waveform to foward bias the P region of the transistor on both half waves of the alternating wave. THANK YOU!!! I never comment. But today you made me. So thanks.
This was incredibly helpful for understanding biasing. The only recommendation I would have for future videos is to include visuals of the paper schematic while you setup the physical circuit to make it easier to follow the actions you are taking (assuming you have what's needed editing wise to do this). Other than that great job!
What you say is correct for isolated power supplies and scopes. On the other hand some scopes grounds are equal to power line ground and also true for non-isolated power supplies. Therefore, you viewers may have big problems (shorts) if the equipment is not isolated. Need some care here. Thanks for your video.
I've been thinking about putting a DC forward bias in the actual guitar circuit. It seems like it would work, I'm having no luck finding any information specifically for this application. The idea I'm have is to have coupled capacitors, one after the pickup(s) signal(after switch), then input a DC current to give a forward bias through volume and EQ tone control, then have the other coupling capacitor to block the DC from going to the jack output. Like throwing in some small signal diodes, before the signal exists through the other coupling capacitor, to setup a switch for a little distortion. The EQ is only going to be a filter, no transistors/amplification, cut only. It seems like it would work, the point being to make the cut pots more independent, not interacting by pushing signal backwards(like turning resistance down on a base cut but then the treble cut at full resistance pushing high frequencies through the low cut to ground)
Than You! Finally someone who is speaking English on this subject. Question, do you know of any off the shelf break out boards for this circuit, preferably one with a 3.5mm input jack? Thanks again 👍
I have a 0.5sinwt signal to be read by an ADC that allows only 0-1V inputs. Would like to know if there would be isolation issues because the ADC is built-in, hence the ground would be common with the FPGA ground all along. Next, I would like to know which method would be better to include a 0.5V bias- single supply opamp or the one you mentioned in this video.. Thanks!
Hey @Simply Put Great Video Man! but @0:36 you said DC bias messes up Audio Signals any thoughts on how to measure audio signals with microcontroller without messing it with DC bias. Thanks:)
I have this very same problem, but need a different solution. I'm building a laser synth with a Teensy and quad audio shields, which have capacitors on the outputs that block my deliberate DC offset signals for beam positioning and color control for RGB laser diodes. So, I tried shorting across the audio shields' output caps and adding a noninverting op-amp buffer. But, that didn't work. All I'm getting is noise. Perhaps I've blown the audio shield?🤔 Yes, I've also considered summing in the offsets, post-cap, by using a different quad DAC. But, it only passes voltage levels via I2C, instead of the Teensy's I2S audio. They both have the same I2C addresses of 0x60 & 0x62.😢 Isn't there a way to simply get rid of the output capacitor and be careful about clipping?😎
I have a question, when I am connecting the power pin of my circuit (pcb) to the generated DC biased AC voltage, the signal is getting highly distorted... how can I connect exactly this signal to my pcb?
I like how you explain things, but you really need an overhead camera for your breadboard. I am not sure which resistor you changed around to offset your too small capacitor?
You could do that, but you'd also be blocking slightly more than half of the AC signal as well. It would be in essence a "half-wave rectifier". The capacitor works because the AC signal switching between positive and negative causes the capacitor to charge and discharge, which allows a current "through" (not actually through but it behaves as if it's going "through"). The DC signal just charges the capacitor to a certain steady level and so it doesn't go "through" except right when you first turn it on. Fun fact: If your audio signal is not changing, it blocks the signal too! Even if your signal is not zero, if the signal is not changing, it is not making the capacitor charge and discharge, which means there is no current "through" the capacitor, and to the output side of the subcircuit, it appears exactly as if the signal were a steady zero. You can only bias and amplify a changing signal this way.
@@simplyput2796 I have a 0.5sinwt signal to be read by an ADC that allows only 0-1V inputs. Would like to know if there would be isolation issues because the ADC is built-in, hence the ground would be common with the FPGA ground all along. Next, I would like to know which method would be better to include a 0.5V bias- single supply opamp or the one you mentioned in this video..
When you're trying to eliminate all AC/analog noise, it's common to use a 100nF as it tends to be "pretty good in most situations". If you want to do better, have two capacitors in parallel, and make the other one 10nF and put it closer to the thing you want protected from noise: The smaller capacitor reacts faster (so closer is better) and the bigger capacitor supplies more power so it handles the bigger ripples. You can always add more capacitors if you want: The worst that happens is you waste cost and board space. The best thing to do is observe what happens to your circuit under testing, and if you have noise issues, add capacitors.
Could you please provide the source you were referring to, perhaps I missed it but I do not see that linked. Also, does this apply a phase shift to the input signal? It does not look like it form the video, but it can be hard to tell with a square wave.
I’m asking purely out of curiosity for how others think about electronics. (I know ~nothing myself) Why would the input signal be phase shifted? The bias voltage only adjusts the «height»/distance to «ground», i don’t see how that would delay or invert the oscillation..
@@davidaep Having capacitors in a circuit can add a phase shift quite easily. However a circuit analysis is required to see if there is a net affect large enough to care. Just learning about electronics myself, and this circuit is for piping vibration data into an Arduino where the frequency dependant and phase are critical to the application.
But after looking at your the circuit more, the capacitor looks like it just reduces AC noise on the signal and would not introduce a phase shift. I think I will come back to this particular project in about 2 months, I will comment if I do and have more information which would be helpful for people doing this conversion for AC signals.
Excellent! I never thought Hagrid would teach basic electronics.
Yer an engineer Harry.
Engineering is scientific witchcraft.
The best explanation of the mysterious ‘bias’ ! EXCELLENT
Thanks for this video. Explained it in intuitive terms and not just more jargon.
So helpful. Appreciate the explanation!
Excellent video. Crystal clear presentation. I finally found some of the answers i was seeking.
Thanks.
Definitely subbed.
Hooray! I did it! I built my first amplifier circuit from this, Learned a ton along the way. And have a long way to go.
Thank you! Now i get it. Biasing is like adjusting the sniper's scope so you still get the shot on 'zero'. Lol
A great video that is easy to understand. It has helped me tremendously. Please continue to put out great content like this. No one else puts out this type of content that is down to earth and easy to understand.
I have been searching far and wide for a good enough video on this subject. This was spot on! Thank you
I went through the same thing as you, trying to learn it myself. That's one of the things I'm trying to do with my channel: "I scoured the Internet for crumbs so you don't have to." Glad it helped.
Normally, I don't comment on YT Video's. But your video's are finally giving me deeper understandings in how electronics in general work. The way that you use to describe things is so easy but yet so detailed. Please continue with making these videos!! Greetings from the Netherlands ;)
Beautifully Put. Thank you very much. Keep up the great work.
Bro, your explanation is better than most of my professors hand down!
Thank you 🙏
Great demonstration
Thank you so much sir... I have been confused about this from last 2 years.. you just cleared all my doubt
the magnets on whiteboard = mind blown!
Excellent - thank you - I love the fuzzy felt !
Hey man. Just wanted to say. I'm an B1 aircraft engineer (B1 = Mechanical) who was wanting to change his discipline to B2 ( B2 = electrical) and have been studying for weeks preparing for my exam and have been wondering for a solid 3 hours now how on earth a transistor works on the negative half wave of the AC waveform. I scoured the internet and past papers and study materials for 3 hours until now 2am. And lo and behold. All it took was 1 min and 1 second into your video to simply explain exactly what i needed to know. You bias the signal by shifting it up to a positive waveform to foward bias the P region of the transistor on both half waves of the alternating wave. THANK YOU!!! I never comment. But today you made me. So thanks.
Very helpful and exactly what I was looking for - thanks!
Why couldn't have my professors have been this good in explaining back in my college days.
thanks, i needed to add dc bias for a class d amplifier and you helped me
you are a genius, after a long search u answered the question that confused me.....
Love it! you're so clear.
Great Explanations ! Bravo !
Very Very Very clear explaining. thanks a lot
This was incredibly helpful for understanding biasing. The only recommendation I would have for future videos is to include visuals of the paper schematic while you setup the physical circuit to make it easier to follow the actions you are taking (assuming you have what's needed editing wise to do this). Other than that great job!
What you say is correct for isolated power supplies and scopes. On the other hand some scopes grounds are equal to power line ground and also true for non-isolated power supplies. Therefore, you viewers may have big problems (shorts) if the equipment is not isolated. Need some care here. Thanks for your video.
Grea t Effort! Really helpful!
This video made me subscribe
Thank you, got it. Finally!
Thanks a lot!
Excellent!
I've been thinking about putting a DC forward bias in the actual guitar circuit. It seems like it would work, I'm having no luck finding any information specifically for this application. The idea I'm have is to have coupled capacitors, one after the pickup(s) signal(after switch), then input a DC current to give a forward bias through volume and EQ tone control, then have the other coupling capacitor to block the DC from going to the jack output. Like throwing in some small signal diodes, before the signal exists through the other coupling capacitor, to setup a switch for a little distortion. The EQ is only going to be a filter, no transistors/amplification, cut only. It seems like it would work, the point being to make the cut pots more independent, not interacting by pushing signal backwards(like turning resistance down on a base cut but then the treble cut at full resistance pushing high frequencies through the low cut to ground)
Than You! Finally someone who is speaking English on this subject. Question, do you know of any off the shelf break out boards for this circuit, preferably one with a 3.5mm input jack? Thanks again 👍
Just wanted to know if there could be isolation issues. An ADC will be reading the biased signal.
I have a 0.5sinwt signal to be read by an ADC that allows only 0-1V inputs. Would like to know if there would be isolation issues because the ADC is built-in, hence the ground would be common with the FPGA ground all along.
Next, I would like to know which method would be better to include a 0.5V bias- single supply opamp or the one you mentioned in this video.. Thanks!
Hey @Simply Put Great Video Man! but @0:36 you said DC bias messes up Audio Signals any thoughts on how to measure audio signals with microcontroller without messing it with DC bias.
Thanks:)
I have this very same problem, but need a different solution. I'm building a laser synth with a Teensy and quad audio shields, which have capacitors on the outputs that block my deliberate DC offset signals for beam positioning and color control for RGB laser diodes.
So, I tried shorting across the audio shields' output caps and adding a noninverting op-amp buffer. But, that didn't work. All I'm getting is noise.
Perhaps I've blown the audio shield?🤔
Yes, I've also considered summing in the offsets, post-cap, by using a different quad DAC. But, it only passes voltage levels via I2C, instead of the Teensy's I2S audio. They both have the same I2C addresses of 0x60 & 0x62.😢
Isn't there a way to simply get rid of the output capacitor and be careful about clipping?😎
I have a question, when I am connecting the power pin of my circuit (pcb) to the generated DC biased AC voltage, the signal is getting highly distorted... how can I connect exactly this signal to my pcb?
I like how you explain things, but you really need an overhead camera for your breadboard. I am not sure which resistor you changed around to offset your too small capacitor?
One could use an AC-coupled trigger while the channel stays DC-coupled (I recognized this fact a few minutes ago when I tried it myself) ;)
Thanks
Hi, Can you make a video how AC Bias improves sound recording in earlier tape recorders. Thanks in advance
That sounds interesting. I'll add it to my list!
Can't we put diode between ac input and voltage divider to block DC current towards input? Thanks for such an awesome video.
You could do that, but you'd also be blocking slightly more than half of the AC signal as well. It would be in essence a "half-wave rectifier". The capacitor works because the AC signal switching between positive and negative causes the capacitor to charge and discharge, which allows a current "through" (not actually through but it behaves as if it's going "through"). The DC signal just charges the capacitor to a certain steady level and so it doesn't go "through" except right when you first turn it on. Fun fact: If your audio signal is not changing, it blocks the signal too! Even if your signal is not zero, if the signal is not changing, it is not making the capacitor charge and discharge, which means there is no current "through" the capacitor, and to the output side of the subcircuit, it appears exactly as if the signal were a steady zero. You can only bias and amplify a changing signal this way.
@@simplyput2796 I have a 0.5sinwt signal to be read by an ADC that allows only 0-1V inputs. Would like to know if there would be isolation issues because the ADC is built-in, hence the ground would be common with the FPGA ground all along.
Next, I would like to know which method would be better to include a 0.5V bias- single supply opamp or the one you mentioned in this video..
I have a question, how do you choose the value of the capacitor?
When you're trying to eliminate all AC/analog noise, it's common to use a 100nF as it tends to be "pretty good in most situations". If you want to do better, have two capacitors in parallel, and make the other one 10nF and put it closer to the thing you want protected from noise: The smaller capacitor reacts faster (so closer is better) and the bigger capacitor supplies more power so it handles the bigger ripples. You can always add more capacitors if you want: The worst that happens is you waste cost and board space. The best thing to do is observe what happens to your circuit under testing, and if you have noise issues, add capacitors.
@@simplyput2796 Thank you very much sir! :)
Could you please provide the source you were referring to, perhaps I missed it but I do not see that linked. Also, does this apply a phase shift to the input signal? It does not look like it form the video, but it can be hard to tell with a square wave.
I’m asking purely out of curiosity for how others think about electronics. (I know ~nothing myself) Why would the input signal be phase shifted? The bias voltage only adjusts the «height»/distance to «ground», i don’t see how that would delay or invert the oscillation..
@@davidaep Having capacitors in a circuit can add a phase shift quite easily. However a circuit analysis is required to see if there is a net affect large enough to care. Just learning about electronics myself, and this circuit is for piping vibration data into an Arduino where the frequency dependant and phase are critical to the application.
But after looking at your the circuit more, the capacitor looks like it just reduces AC noise on the signal and would not introduce a phase shift. I think I will come back to this particular project in about 2 months, I will comment if I do and have more information which would be helpful for people doing this conversion for AC signals.
Can anyone test this out and give feedback? investigate circuit solver on the playstore!
this was very fast for me to understand. :(
did you chop every other word on purpose? it's ruining your vid btw.