Over time, your channel has become obviously and by a wide margin the best in class on RUclips and the net. Were else can us humans find such great expertise, experience and knowledge!
Your contributions have become an integral part of my hobby. I am 54 years old and started with the hobby electronics almost two years ago. I have already learned a lot from you. Thanks! Happy New Year!
Happy New Year to you and yours, Paul. Thank you for sharing your experience and knowledge, one of my key resources as I attempt to turn a patchy lifelong fascination into coherent and productive skill. Hope to see you reach that well-deserved 100K in 2020.
Happy New Year Paul, just got back home from visiting family and friends. Nice to see the mixer circuit work well and i learned some things bout opamp terminations.
Happy new year Paul! Just wanted to ask if you maybe plan to test the ANENG AN888S benchtop multimeter in the near future? I find this thing pretty interesting, since it's affordable for a bench device and I wanted something like this for a long time.
Happy new year to all. thanks for the demo and advice. Also , In the datasheets of opamps, logic gates, etc there are some remarks about unused pins eg. LM358 , SN7404 ( search for "unused" :D)
How have I not though to play with wave types using an opamp while being hooked up to a scope. I’ve done it as a tone generator but never hooked up the output to see the cool wave patterns you can make. This video rocks Paul, I know what I’m doing today that’s for sure.
Just a quick question, to terminate the op-amp with a unity gain setup, shouldn't you be wiring the terminals the other way around (inverting input to the output and non-inverting to ground) to have a negative feedback circuit? that way the output will always be at ground level. Or did I misunderstand (I'm still an engineering student so I might not now yet, but always looking to learn :D )
What about different impedance sources with this such as an electric guitar and a headphone jack out of a cell phone? Also, is there a simple way to time shift one of these signals so you can play with phase cancelation? A speaker hooked to your circuit might have made it a little clearer to understand the combined wave.
Probably best to use a separate op amp buffer between various audio sources and the mixer inputs to keep impedances from interacting and loading the inputs that are susceptible. Phase shifting 180° for a complete cancellation I figure could be done with an inverting op amp unity gain configuration to mix with the original signal, but maybe RC filter networks can be used to shift the phase at specific frequencies but I don’t know how controllable that is. Something to play with maybe.
NOW THE NEXT TIME I GO TO ROCK CONCERT I CAN WATCH THE MIXERS DO THE MIXING AND,THINK OF YOUR DEMONSTRATION.KEEP A ROLLING KEEP A ROLLING DOWN THE LINE[BOB SEGAR].
I do not think it is good practice to connect an amplifier output back to its positive input. There be oscillation and limit cycles. I think the correct termination arrangement for an under used op-amp should be: output connected to the inverting input, and non-inverting input connected to ground. When the inverting input is connected to the output, the op-amp becomes a non-inverting, unity gain, high impedance buffer, similar to the emitter follower. Then connecting the non inverting input to ground biases the output to ground potential. This arrange is some times used in single rail operation to provide a low impedance regulated half rail. Where a potential divider of equal value resistors are used to define the half rail voltage. And the the follower is used to convert this to a low impedance. The advantage is that the bias resistors can be of high value, drawing less current from the supply, while still generating a low impedance half rail that can be used as a ground reference for the remaining op-amps in the package. There limitation to this topology, but it works provided not too much current is taken or feed to this reference.
@@learnelectronics I was going by the commentary in the video. I have added an explanation of why the correct arrangement works and some further application of the circuit topology. I was not attempting to score points.
Nice projects, good info. It would be nice to see a simple schematic of the circuit you're working with. It could help people who might want to re-create your projects to have that guide. Thanks.
This TL-072 op amp has a certain frequency range it can operate in? This is determined by the slew rate, correct? Is there anything we can do with external components to increase the apparent slew rate?
A better figure to look at is the unity gain frequency and the gain vs. frequency chart in the datasheet. A good rule of thumb to follow is to make sure that the open-loop gain is at least ten times that of your closed-loop (ie, with feedback) gain at your desired maximum frequency. You also have to pay attention to the phase shift vs. frequency curve, otherwise you could wind up with an oscillator if you have some phase-shifting components in your feedback network.
3:05 Just wondering if both frequencies are direct multiples of each other (5KHz sine wave and 10KHz square wave) then why is the square wave acting all weird on the scope?
Termination must have negative feedback. I switched them around when the current went from .579 to .529ma.
Over time, your channel has become obviously and by a wide margin the best in class on RUclips and the net. Were else can us humans find such great expertise, experience and knowledge!
@@beanmeup9902 I just ordered an RPi4 and stumbled upon your videos. I'm commenting here to say thank you for sharing.
Didnt know about termination, thanks!!!
Glad this comment is here. I was starting to think I must be crazy.
Your contributions have become an integral part of my hobby.
I am 54 years old and started with the hobby electronics almost two years ago. I have already learned a lot from you.
Thanks!
Happy New Year!
Glad to help. Happy new year
Love your delivery. Great channel. No BS. I'm on year 2 of learning electronics, and im biten by the bug!
Happy New Year to you and yours, Paul. Thank you for sharing your experience and knowledge, one of my key resources as I attempt to turn a patchy lifelong fascination into coherent and productive skill. Hope to see you reach that well-deserved 100K in 2020.
happy new year to all.. i hope in 2020 we all see clearer...
XPFTP ugh that is such a bad pun. I love it.
I'm going to build a 6 channel stereo mixer using this, Thank you for the know-how. Happy new year everyone :)
Make vid on digital pots? Thanks for your kind work.
Happy New Year and don't forget Hindsight is always 2020 looking back it's still a bit fuzzy.
Nice added tip of the unused floating amp. That I didn't know though I wondered about it because I saw it in some diagrams. Thanks!
Happy new year.
Excellent. The output looked inverted.
Happy New Year Paul, just got back home from visiting family and friends. Nice to see the mixer circuit work well and i learned some things bout opamp terminations.
Happy new year Paul! Just wanted to ask if you maybe plan to test the ANENG AN888S benchtop multimeter in the near future? I find this thing pretty interesting, since it's affordable for a bench device and I wanted something like this for a long time.
I'm waiting on one to arrive.
@@learnelectronics That is great news! I guess, I'll wait then before getting one. It looks promising.
Cool man. It's simple and fun. Never did it but will do it soon.
Now to bump it up from there and go over gyrators and op-amps and create EQ boost/cutters
I think it should be non-inverting input (+) to ground and inverting input (-) to output.
Correct I switched them
Happy new year to all. thanks for the demo and advice. Also , In the datasheets of opamps, logic gates, etc there are some remarks about unused pins eg. LM358 , SN7404 ( search for "unused" :D)
How have I not though to play with wave types using an opamp while being hooked up to a scope. I’ve done it as a tone generator but never hooked up the output to see the cool wave patterns you can make. This video rocks Paul, I know what I’m doing today that’s for sure.
Happy new year, Mike!
Just a quick question, to terminate the op-amp with a unity gain setup, shouldn't you be wiring the terminals the other way around (inverting input to the output and non-inverting to ground) to have a negative feedback circuit? that way the output will always be at ground level. Or did I misunderstand (I'm still an engineering student so I might not now yet, but always looking to learn :D )
Yes, it was backwards, that's why I switched it.
Happy New Year Paul
thanks so much! My new years resolution is to build, measure and describe 20 circuits. I will attempt mixing tomorrow!
What about different impedance sources with this such as an electric guitar and a headphone jack out of a cell phone? Also, is there a simple way to time shift one of these signals so you can play with phase cancelation? A speaker hooked to your circuit might have made it a little clearer to understand the combined wave.
Probably best to use a separate op amp buffer between various audio sources and the mixer inputs to keep impedances from interacting and loading the inputs that are susceptible.
Phase shifting 180° for a complete cancellation I figure could be done with an inverting op amp unity gain configuration to mix with the original signal, but maybe RC filter networks can be used to shift the phase at specific frequencies but I don’t know how controllable that is. Something to play with maybe.
I've been looking for this. Thanks man, you're a great help.
Happy New Year and great lesson. I would have kept the 10 k resistors in front of the pots.
Another banger. Keep em comin
Happy new year, dude! All the best wishes! 😊
Pretty nice project!
Why my brain start freestyling to the beat at the end?
NOW THE NEXT TIME I GO TO ROCK CONCERT I CAN WATCH THE MIXERS DO THE MIXING AND,THINK OF YOUR DEMONSTRATION.KEEP A ROLLING KEEP A ROLLING DOWN THE LINE[BOB SEGAR].
I do not think it is good practice to connect an amplifier output back to its positive input. There be oscillation and limit cycles.
I think the correct termination arrangement for an under used op-amp should be: output connected to the inverting input, and non-inverting input connected to ground.
When the inverting input is connected to the output, the op-amp becomes a non-inverting, unity gain, high impedance buffer, similar to the emitter follower. Then connecting the non inverting input to ground biases the output to ground potential.
This arrange is some times used in single rail operation to provide a low impedance regulated half rail. Where a potential divider of equal value resistors are used to define the half rail voltage. And the the follower is used to convert this to a low impedance. The advantage is that the bias resistors can be of high value, drawing less current from the supply, while still generating a low impedance half rail that can be used as a ground reference for the remaining op-amps in the package. There limitation to this topology, but it works provided not too much current is taken or feed to this reference.
Please read pinned comment.
@@learnelectronics I was going by the commentary in the video. I have added an explanation of why the correct arrangement works and some further application of the circuit topology. I was not attempting to score points.
Nice projects, good info. It would be nice to see a simple schematic of the circuit you're working with. It could help people who might want to re-create your projects to have that guide. Thanks.
The schematic is in the previous video: ruclips.net/video/RjraU0lmsKw/видео.html
The only change are pots instead of resistors.
This TL-072 op amp has a certain frequency range it can operate in? This is determined by the slew rate, correct? Is there anything we can do with external components to increase the apparent slew rate?
A better figure to look at is the unity gain frequency and the gain vs. frequency chart in the datasheet. A good rule of thumb to follow is to make sure that the open-loop gain is at least ten times that of your closed-loop (ie, with feedback) gain at your desired maximum frequency. You also have to pay attention to the phase shift vs. frequency curve, otherwise you could wind up with an oscillator if you have some phase-shifting components in your feedback network.
Have a Happy New Year Paul!🎉🎊
Happy New Year! de WQ1I 73's
TI has a TechNote about termination. It basically says the same as Paul.
www.ti.com/lit/an/sboa204a/sboa204a.pdf
Happy New Year Paul.!!! Thanks for the videos... :D
Everyone have a Bless and Safe 2020!
LLAP
First
3:05 Just wondering if both frequencies are direct multiples of each other (5KHz sine wave and 10KHz square wave) then why is the square wave acting all weird on the scope?