Two minor corrections: I mistakenly read the symbol φ (Phi) as α (Alpha). Also, the exponent value 10^-15 is femto, I accidentally said atto which is 10^-18.
@AdityaMehendale7 жыл бұрын
Hi TSPB - You mention around the 42:00 mark that the TIA is 10 MOhm - i.e. transimpedance of 10^7. However you say & use 10^6 in the rest of the segment. Cool explanation though :) Cheers!
@jafinch785 жыл бұрын
I've read you're better off with a Princeton Applied Research PAR-124/126. Stanford? Makes me think of billions in frauds and gross cheats as liberal as around that area can make.
@AdrianRumpold5 жыл бұрын
And "noises of source" around 3:40 ;) Thanks for the great video and your amazing skill of explaining these highly technical topics!
@TheCondoInRedondo2 жыл бұрын
Glad you caught this. I was just now about to post that (if you were small enough) you could conceivably COUNT THE ELECTRONS if you were truly measuring attoamps. ;) I'm guessing that lock-in amps are used to pull the feeble Voyager signals out of the cosmic background.
@nftmaster20507 жыл бұрын
"And here I'm using centimeters, because I'm not insane" :D
@trickyrat4837 жыл бұрын
Clearly Mr Trump needs to build a wall around this commie's house. :)
@JackZimmermann7 жыл бұрын
Epic! Haha!
@hpux7357 жыл бұрын
Jinx! Lol, how many people commented that!!
@SidneyCritic7 жыл бұрын
What's wrong with using cubic furlongs per fortnight. lol
@RFlynn-rs6yw7 жыл бұрын
I like to use chain, link, or rod (pole) just to confuse people.
@video99couk2 жыл бұрын
1:15 Exactly the same response I had when I contacted a company about demonstrating a product they made which has not been covered on KZbin. They said that they are the top result for anyone searching for that product already and no they didn't one to lend me one to feature. You do have to wonder what the marketing people are on, when they get a chance to have someone in that field, demonstrate their product, but they turn it down. Like you, I demonstrated one of their products and explained why I couldn't show any others.
@maurosobreira86957 жыл бұрын
And once again you crossed that thin line between awesome electronics and experimental physics - Love it!
@AndySpicer5 жыл бұрын
I’m here watching this a second time because of your latest video. I’m always amazed at how much I learn when I do that. My core knowledge has improved so much over the years from watching your stuff that I now have a much better grasp as I listen to new things. I’m in my 50’s and hadn’t taken a math class since I was 20. It frustrated me that I wasn’t able to remember enough to keep up with you during the videos. I went back to school specifically because of you and I’m now 2 years and 5 math classes in. Thank you!
@Thesignalpath5 жыл бұрын
Happy to hear it! I hope you would find the videos continuously useful.
@schmsimo7 жыл бұрын
Nothing better than a lazy Sunday afternoon with a new episode of the SignalPath 🍿
@yaghiyahbrenner89027 жыл бұрын
Stanford Research. what a bum response! thanks for this video.
@3ffrige4 жыл бұрын
Right? Because they think their the market leaders for Lock In Amplifiers, they are up there on their high horse acting all mighty and shït. Reminds me of IBM back in the days and look at what happened.
@carlosvazquez44012 жыл бұрын
Thank you, Shariar. Amazing explanations. Maybe it is worth to mention that in this lock-in amplifier very often the input FETs are damaged, when the signal is overload.
@cncdavenz7 жыл бұрын
Hi, I have pulled apart many industrial instruments over the years to see how they worked. Some had choppers and now I know what it was for. Thanks for the very concise explanation. Cheers Dave.
@rkupka7 жыл бұрын
"...I'm using centimeters, because I'm not insane." Very nice :)
@davidgustafik79687 жыл бұрын
I was going to post this exact comment.
@DanielRowe7 жыл бұрын
made me laugh
@shazam62745 жыл бұрын
Jimmy Carter single handedly stopped the USA from changing to the metric system. he was also the only president who was an engineer.
@ahmedgaafar53694 жыл бұрын
he is absolutely correct.
@petr_e7 жыл бұрын
That wonderful video combines signal processing, electronics and physics together! That was an introduction of lock-in amplifiers to me. Thank you!
@The_Paya7 жыл бұрын
These might be in (my) top 3 experiments you've performed with high end specialized instruments. Immense bummer that SR couldn't lend you their latest machinery to run them on. Still awesome and enlightening. Thank you.
@techtalkmike49687 жыл бұрын
Outstanding tutorial video! The amount of time and effort and knowledge sharing is exemplary! As a TSP Patreon supporter, the ratio of bang to buck is enormous.
@gerryjamesedwards1227 Жыл бұрын
"I'm using centimeters, because I'm not insane." LOL
@dwagner64 жыл бұрын
I’m in school for EE and am working my way through your videos. Even if I don’t understand many topics you discuss, I’m constantly researching new things and just hoping I absorb the rest through osmosis. Thank you!
@jimmy_jamesjams_a_lot41714 жыл бұрын
‘Measure the speed of sound’. That is precisely what this device was exactly invented for. I’m quite positive it was at Princeton, hence the reason why the big competitor to the Stanford is the PARC, where it was invented I think. Great stuff, thanks for giving me a use for my Kiethley programmable current source!! Maybe I can justify keeping it now!!
@kissingfrogs7 жыл бұрын
That was awesome. An experiment demonstrating how to extract signal from within the noise and measure the speed of sound was enlightening. Thankyou Shahriar.
@JetNmyFuture7 жыл бұрын
Breaking down the math and block diagram was awesome! Loved this one.
@lazyman1143 жыл бұрын
I've watched about 50 of your videos so far and this might be my favorite.
@bloodyl_uk7 жыл бұрын
Amazing job dude, totally in awe of the sheer amount of modern science and communication techniques you've hidden inside what appears to be a fun way to test gear and measure the speed of sound.
@Bmcarroll17 жыл бұрын
I learn a lot from the tutorials. Thanks again!
@jman517 жыл бұрын
We had exactly the same experience -- I too worked in an ultra-fast optics lab in undergrad, and these were truly "black boxes" to me until I found out how they worked many years later. Thanks for the video!
@simonfitch11207 жыл бұрын
Your videos are always interesting, but this one was astonishing to me. Such a simple math principle leads to a device which can do the seemingly impossible. Thank you so much for this one.
@pa4tim7 жыл бұрын
Very nice experiments. I am building a few opacity meters and was testing some photocells a few days ago . (like measuring the sun-nano dark current). I do not have a locking amplifier and I had a hard-time measuring steady under 10nA (the meters I used have pA resolution) so I am really impressed by the measurements you showed and the very clear explanation, Thank you.
@baghdadiabdellatif15812 жыл бұрын
Great work 👌 Thank you Greetings from north Africa (Algerian dezert)
@ocean61323 жыл бұрын
This is greatest video. I like the tutorial and the two experiments designed very much. Very elegant!
@magnusarvidsson44477 жыл бұрын
Excellent tutorial. Best I have seen on lockin amplifiers. Love your channel.
@omgkingdano7 жыл бұрын
I look forward to these videos. You do a wonderful job as an educator. Keep it up!
@robertw18716 жыл бұрын
Very nice, more techniques presented than are immediately apparent, I’m sure a lot of careful thought went into this, and to make the setup appear rather simple is brilliant, thank you.
@agstechnicalsupport5 жыл бұрын
Great video on lock-in amplifier operation and basic theory, along with beautiful experiments demonstrating its usefulness.
@trixxim9 ай бұрын
Thank you sir. Very intuitive experiment. Please keep it up!
@stefanosmakris56417 жыл бұрын
Another great video. Amazing information. Thank you!
@topherteardowns46796 жыл бұрын
"Using centimeters, because im not insane' lol, love it.
@williamlee93403 жыл бұрын
Very clear LIA application.
@guillemoli7 жыл бұрын
Interesting experiment setup and clear and concise explanation, as usual. Excellent work!
@guillep2k5 жыл бұрын
Very accessibly explanation for a very complicated subject!!! I don't have a degree but I was able to understand everything. Thank you!!
@varjagg Жыл бұрын
This is completely mind-blowing.
@richardshagam86087 жыл бұрын
I wish that I had seen this video years ago. Well done!!!
@adrianramosbardin76092 жыл бұрын
'Here Iam using centimeters, because Iam not insane' Nice touch
@hpux7357 жыл бұрын
"And here I'm using centimeters, because I'm not insane" 😂
@coolnj15 жыл бұрын
Excellent tutorial. Your teaching skill is awesome.
@arijitsharma1236 жыл бұрын
Superb demonstration!! I really enjoyed the video!! I hope you keep making such videos for enhancing our understanding!!
@bfx81857 жыл бұрын
Thx one of the best videos you did. Excellent !!!
@Sixta167 жыл бұрын
Hello BFX! I worked with a two Stanford SR830 back then in my first job, in an optical measurement setup. Good to remind myself how these instruments have worked! Also as a sidenote: Two lockins can be used together to make an impedance analyzer ;)
@amciaapple16547 жыл бұрын
I'd like to see how the Lock-In amplifier is used as an impedance analyzer.
@Banks2314 жыл бұрын
Hi The Signal Path, Nice to meet you in ISSCC
@Thesignalpath4 жыл бұрын
Thanks! You too.
@ilyagulko952 жыл бұрын
Great video! I have a follow up question to understand the LIA better - the signal that we are after, does it have to be a lower frequency signal, or can it have high frequency components?
@hoaianhho336 жыл бұрын
I love your ruler. That's awesome. BTW, thank you for your video. That made me understand about lock-in amplifier.
@isacnordin80484 жыл бұрын
Amazing demonstration, easy to follow and understand
@MrManlop6 жыл бұрын
Thanks a lot¡ Wouldn't expect to find such a helpfull video by typing "standford sr530 lock in" in youtube
@ahmedhass1463 жыл бұрын
Woow that is a great demonstration and a nice explanation thank u very much
@Thesignalpath3 жыл бұрын
You are welcome!
@kungfumaster81717 жыл бұрын
As usual top rate content and commentary. Excellent work. Thank you.
@gordonwedman31797 жыл бұрын
Great video as always. Equal I'm sure to a one hour lab presentation at MIT. Thanks for all the work put into these.
@plemli7 жыл бұрын
Can't all this be done digitally after digitising the input ? It's almost an SDR... Very good video, clear and interesting, teaching something that's not widely known.
@AngDavies2 жыл бұрын
Nah, you'd need too much dynamic range/memory to get that kinda resolution, needing to capture the noise at the same time would put a hard limit on how low of a signal you can resolve
@samw30863 жыл бұрын
One of the Achilles heel of this unit is the vertical daughter card that you pointed out. It is flimsily held in place and is easily affected by any pressure on the top of the unit which rests on the top edge of the card. If there is an intermittent connection at the bottom connectors you can lose the phase output and the unlock light comes on even though you get the correct frequency on the display. Except for this, it's a fine unit.
@stanislavsubrt8867 жыл бұрын
Maan this is pure gold. Thank you for this video! Great work as always!
@Starlite43215 жыл бұрын
Incredible. Just incredible...
@kieranj677 жыл бұрын
Excellent as always, thank you!
@matthewvenn7 жыл бұрын
thanks for the video - very interesting. Never even heard of this instrument before.
@paulfletcher8487 жыл бұрын
Truly awesome, thank you.
@JustSomeGuy19677 жыл бұрын
Mind Blown !
@DavidMG992 жыл бұрын
👍👍 22:11 "am using centimeters bcoz am not insane"..😂
@AlexeiPolkhanov7 жыл бұрын
Awesome video! Thank you. I was thinking to use similar setup to measure air humidity more accurately (speed of sound depends on humidity, pressure and temp) but could not find affordable lock-in amplifier on Ebay and was scared to spend money on old one wondering if it is still works.
@naohwatson8545 жыл бұрын
love it.
@iNDREI_Ro Жыл бұрын
My mind is blown. Thanks.
@stonail6657 жыл бұрын
Very Interesting ,Thanks for quality upload. Dorood.
@georgemihai96123 жыл бұрын
Thank you for this video! I apologize if I repeat the comment, I thought I'd posted it already but do you have any videos where you cover the time-constant and RollOff and their implications?
@catt877 жыл бұрын
Thank you for this video. It just made my sunday :D
@stephenstudley1857 жыл бұрын
Shahriar , I am curious as to what real-world practical application a lock-in amplifier might have? I’m also curious what level of miniaturization might be applied to the design? Could it be made as a field instrument, say for audio tracking, amplifying & recording? As always, your videos are nothing short of exceptional! I appreciate your dedication to learning for all classes. Education is the tide that raises all boats! Kind regards!
@Darieee7 жыл бұрын
This video was amazing : thanks !!
@techsinc4 жыл бұрын
The best way to think of this is to think of it as an AC amplifier with a frequency selection bandwidth determined by the fidelity of the driving AC reference signal (within limits of the electronics, of course).
@gauravpalsingh35053 жыл бұрын
Great work
@MertOzdag5 жыл бұрын
Great video, thanks for doing this
@amintorabi34137 жыл бұрын
Excellent video. Ended up watching the entire thing even though I have a lab report due! Out of curiosity, what is the power spec of the front amplifiers of the lock in amp? I would imagine if you want to amplify such small signals without too much noise, you would need to burn a ton of power.
@bobfuller7 жыл бұрын
Wow! I just watched the speed of sound being measured. How awesome is that?!
@bobbybiggs43482 жыл бұрын
How do you account for magnetic coupling between the speaker's voice coils?
@raulalejandrofajardomunoz50742 жыл бұрын
It´s a grat video, but i have a question, for example when i have a photo-electrochemical system, i have a base current caused by the raction, and also de photocurrent with the frecuency of the chopper, the first one is considered as noise? and we only gets the photocurrent of the given frecuency Thanks for the information
@octavmandru92197 жыл бұрын
Cool, now let's hear the butterfly flapping his wings in Brazil - from Texas :)
@wumichael4874 жыл бұрын
Awesome tutorial thank you
@moshet8423 жыл бұрын
Considering the sensitivity required when making this kind of measurement, does that mean sometimes they have to design their own components in these devices like this lock-in amplifier?
@AF6LJSue7 жыл бұрын
Thank you this was really good, I learned something. :)
@forgetful20127 жыл бұрын
Thank you so much for your video. It is the first time I’ve come across "The Signal Path" video and I really enjoyed it. It was very well thought out. I have done some video editing in the past so I appreciate how much work goes into making and editing such videos. I have the exact same lock-in amplifier that you used. I am new to lock-in amplifiers so I’ve decided to start with something very basic. I use a function generator to create a signal, and connect it to both the reference input and the A input. I would expect the phase to be the same as my input signal when I set the output to R and Theta. This is not the case. Would you know why? Also would you know what I should expect in this case for the different output options? Thank you so very much!
@urizung57282 жыл бұрын
Thank you!
@ninsimathew43413 жыл бұрын
Hi. What are the different connectors you have used?
@ninsimathew43413 жыл бұрын
Hi, would anyone be able to help me understand the kind of probes and connectors that are used?
@VinayakaHDamle5 жыл бұрын
Hey! Is there some consideration on types of cables we use.?
@doctorzizo20085 жыл бұрын
I like it.. i am wondering if you can also use the lock in to measure the optical phase delay?
7 жыл бұрын
Very nice video! I noticed at 35:49, when you turn off the light, the sign of the current changes to negative. Perhaps this is some thermo-current from the connectors or some sort of electrochemical cell?
@ResearchAdvantage7 жыл бұрын
What about modulation of the light by driving the laser diode with a square-wave from a signal generator? How does that compare with the chopper?
@benrd91117 жыл бұрын
Very nice experiments 👍
@motherjoon7 жыл бұрын
Amazinggg
@xDevscom_EE7 жыл бұрын
@18:35 I feel like a cat chasing the laser pointer. Not sure how's that idea works. Thanks, another video that have experiment setup more interesting than the instrument itself ;).
@Factory4006 жыл бұрын
I have watched this one twice.....looks like a third pass is needed to make sure I did not miss anything. Next - I need a far bigger bank account if I want to worry myself with atto amps. It really is interesting to see this instrument in action to better understand it's intended use. I can read the data sheet for this and still have no idea what to do with it. Now I get it and that is amazing. As for SRS: They make some truly amazing and unique instruments but they appear to be stuck in 1990 as a company. Color displays are the most exotic feature on the newest gear. They have pretty exotic performance in their analog circuits though and that is what the customers pay for. Not surprised they turned down the offer for a review - it appears they are plenty busy and have little interest in general purpose marketing.
@railgap4 жыл бұрын
Did you contact the factory (oops) or did you contact the local rep? If you contacted the local rep and you got the brush-off, I would be shocked.
@Thesignalpath4 жыл бұрын
I just called them directly. Not sure who I got. :(
@georgethomas94365 жыл бұрын
Okay. Where can i get that ruler? I know many want to know. Great video.
@KrissyD-px9gj8 ай бұрын
I finally understand the math Just clicked Very smart whoever first came up with lockin amplification
@ekarademir7 жыл бұрын
Wouldn't square nature of the wave chopping affect the frequency that you are measuring? We would be adding loads of frequencies to the assumed sine wave.
@Konecny_M7 жыл бұрын
That depends on the lock-in mixers used. If they mix the input with sinewave phaselocked to source, harmonics are rejected. However in simpler instrumentation cases you might opt for switched mixer, where it is ineed the case case with harmonic components of modulated signal being detected and integrated into the result.
@PileOfEmptyTapes7 жыл бұрын
It occurred to me that you could probably use a lock-in amplifier with an appropriate frontend and antenna to lock your lab reference oscillator to the WWV carrier @ 10 MHz (with a major integration time constant to account for the eccentricities of shortwave propagation). Not sure whether it would be any easier or cheaper than a GPS-controlled reference though.
@Thesignalpath7 жыл бұрын
Interesting. However, the lock-in amplifier has only 200kHz bandwidth.
@PileOfEmptyTapes7 жыл бұрын
I was suspecting something along those lines. Still, nothing that some synchronous downmixing of both signals couldn't potentially fix, though that's clearly not helping the complexity factor (especially if you have to resort to either dual conversion or I/Q mixing).
@sputnik42166 жыл бұрын
How about WWVB at 60kHz ?
@matthewgrimsley45067 жыл бұрын
Great job. For some time, when my professor referred to these I thought that "lock-in" was a person's name.
@mitchwright15587 жыл бұрын
Great topic and video, is there a schematic for the SR530 ?
@Thesignalpath7 жыл бұрын
mitch wright I could not find one.
@andrewsweet437 жыл бұрын
A random question. Why do you spell the letter φ as "alpha"? The letter is pronounced "phi" or "phee" :)
@Thesignalpath7 жыл бұрын
I had the equation written with alpha first and said alpha again with the new slide. I added a sticky comment correction. Thanks!
@arashghasemi3 жыл бұрын
If the source signal is in order of GHz then how to integrate the product of source and reference since it becomes almost pure spurious noise ???