I too as a kid wondered why there were light bulbs in oscillators! One neat trick that I used ( I got it from an old book) is a radio squelch circuit made from two ten ohm resistors and two number 49 light bulbs. It's a bridge. I used it for years on a 6 meter SSB receiver. It goes between the speaker and the receivers audio out connection. You increase the audio gain until the lamps heat up enough to balance the bridge and then the speaker goes silent. Any signals that come in unbalance the bridge and un-mute the speaker.
@ingussilins6330
Жыл бұрын
Thanks for interesting idea.
@euroe12
5 жыл бұрын
KZitem decided I needed to see this video. Even though it seems to be six years old, it showed up on my feed. It brought back memories of when I was repairing audio gear in college. Our HP generator got a little unstable and I decided to crack it open. Imagine my surprise when I ran across a large (for something found inside a piece of gear), odd looking light bulb. Being young and dumb, I assumed the bulb was bad and ordered another one. I forget what was bad, but it's not a spoiler to report that it wasn't the bulb. Such a simple, elegant means of gain control. Great memories.
@listerdave1240
6 жыл бұрын
One of my earliest electronics projects was a Wien bridge oscillator using a 741 op-amp. That was some forty or so years ago but I somehow clearly remember the struggle to get it to work and how I finally eventually succeeded. I had decided the problem was that the 741 could not drive enough current to warm up the lamp enough and I couldn't find a smaller lamp - the best I had was a bulb form a Christmas light string. In an attempt to solve that I put in an emitter follower stage to boost its current output capability. That could then easily drive the lamp but no matter how I adjusted it I could tell just by hearing that it was severely distorted. I then solved it in a different way. I replaced the lamp with an LDR. This acted as the gain controller. I then used the emitter follower transistor to drive the lamp which illuminated the LDR acting as the actuator for the gain control. With a lot of tweaking I finally got it to work. Many years later when I had access to an audio spectrum analyser at school I tested it and was pleased to find out it actually had very low distortion.
@inayathussain9236
5 жыл бұрын
First time in my life i have read such a lengthy comment but to be honest i enjoyed it
@jeriellsworth
12 жыл бұрын
This doesn't have enough distortion for indie bands. :)
@goodun6081
5 жыл бұрын
I never had children of my own, my wife has two grown kids from her earlier marriage, but had I had my own daughter I would have liked her to be very much like you.
@AshutoshSingh-to9vx
4 жыл бұрын
Wholesome
@Fishbowlfx8
6 жыл бұрын
It is 2018 and I just discovered this is the most elegant way to learn electronics. Thanks
@robertjohansen7482
5 ай бұрын
I built many Wien bridge oscillators though out the years. Another great tutorial for those beginning to understand analog circuits
@stevejagger8602
Жыл бұрын
Thank you for the reminder. I have used one of those tiny indicator lamps in a reference 1khz oscillator that provided the synchronising bleep from the sound mixer to the audio recorder at the beginning of every take shot on a 16mm film camera. Everything was powered from the camera battery. I was amazed at the stability of the signal level that this simple technique provided.
@m1dlguk
12 жыл бұрын
Between you and Dave from EEVblog I have rekindled my interest in building stuff! Thank you. I was the only person at school who was interested in electronics, as a result there was no point in teaching this. I think I will be making my shack more focused toward construction when I move later next year.
@DestroManiak
9 жыл бұрын
piezoelectric effect can be observed on the oscilloscope at 2:43
@ravibhosle1991
5 жыл бұрын
DestroManiak hey Sir i am ravi from india can i get your emails or other contacts
@dahamalanzy1353
5 жыл бұрын
Please add the value of the items to the circle and can be used as a filter
@iangrant9675
5 жыл бұрын
When her hand hits the paper? How?
@iangrant9675
5 жыл бұрын
Polyurethane varnish is piezoelectric?!
@tommihommi1
5 жыл бұрын
@@iangrant9675 ceramic capacitors are everywhere and are piezoelectric.
@geoffbarber2860
9 жыл бұрын
Hi Jeri, Just seen your video regarding the Wien Bridge oscillator which reminded me of an interesting story relating to what I believe was the first use of a light bulb in this circuit. My story starts in 1967 when my college class mates wanted to build an audio generator as part of the practical element towards out final college exam. Out tutor, the wonderful Mr Dave King convinced the class to use the Wien Bridge circuit which used a glass thermistor in the feedback (pre op amps) circuit. Unfortunately, I was the only one in the class who had a glass thermistor and were too expensive even to purchase in bulk. Therefore, not wanting to abandon the project, Mr King went home that night and designed a circuit using a light bulb. As his design was so good, he published the project in one of the UK's leading electronic magazine, Practical Electronic. I still use my original audio oscillator in my workshop. It used to have a label on the front “May 1967). Therefore I believe our tutor was the first UK engineer to design this type of circuit. Regards Geoff.
@buffplums
3 жыл бұрын
Gosh you are an amazingly clever person… I love seeing someone so driven
@ModernCriminal
6 жыл бұрын
1938 - HP Audio Oscillator Model 200A&B, use of a light bulb was Bill Hewlett's idea. Thanks for the great video!
@scienceraven1200
4 жыл бұрын
nice to discover your channel Ellie. I remember when I was a kid, I would be doing descartes 5th degree equations with either hand while watching TV, and I would also be thinking about op-amps with lightbulbs. :) coincindence.
@Bodragon
5 жыл бұрын
I'm sorry. I've just come back to this video. Revisited, if you like. I GET IT. Thank you so much. Of all the videos out there trying to explain Wien bridge oscillation, *THIS IS THE ONE FOR ME* This is *MY LIGHTBULB MOMENT* Thank you so much lady. I am so excited right now, I need to go lie down. LOVE IT! FREAKIN' LOVE IT.
@TheWannaramble
Жыл бұрын
that Jeri-style hair falling down over one eye is so beautiful
@_pilly
5 жыл бұрын
Nice video, I just had the experience of building one for an am transmitter circuit! Took an annoying amount of tweaking to get the thing to work right
@FarleyHillBilly
11 жыл бұрын
@cubemike99 The lamp is a 3V 15mA 'grain of rice' as used on model trains, get it on EBay. Resistor at the top of the diagram is a 1k pot. R1+2 is a10k dual pot with a 560R in series with each section. C1+2 100nF for about 200Hz to 2Khz. Opamp is a 741 or TL081.
@KC9IEQ
11 жыл бұрын
Great demonstration! Actually the first resistance tuned oscillator with a non linear element (incandescent lamp) was Bill Hewlett's brainchild alone- It was his Stanford University thesis project in 1938. Dave Packard was on the east coast and had just been married. The partnership happened shortly thereafter, although they had met and been good friends throughout their time at Stanford. The other BIG advantage to using a lamp was amplitude stability over a very wide frequency range!
@IvanIvan1974
5 жыл бұрын
Nice to see the good old Wien bridge oscillator around. Like all oscillators of this type the main task is to overcome the losses to achieve a non decreasing amplitude of the sine wave. In the transfer function of the closed loop you easily spot out that the linear term in the denominator must be zero to reach a stable amplitude of the output. Here´s where the light bulb comes in. The bulb has a resistance which is dependent of the current flowing through it. The more current the more resistance. Filament heats up slowly resistance increases slowly. The "slow" behaviour is important to avoid a resistance changing according(along) to the sine wave. But you have to watch for the proper DC bias point because the bulb does not behave the same way in the whole current range. You have to spot out the highest slope of the resistance vs. current function R(I). Not every bulb works, if the slope is too flat you can´t compensate the lack of amplitude with the gain of the amp, because the gain would not grow enough due little resistance change of the bulb. Once you have figured out how to set the DC operation point of the bulb you also know the current which flows through the resistors for the negative feedback loop. That's one equation. The gain which is set by the negative feedback resistors is also a parameter for the oscillation criteria. You need just the right amount of gain to get the circuit oscillate with a stable amplitude. That's the other equation. Now the linear equation system can be solved for the two negative feedback resistors involving also the resistance of the bulb. For the frequency determining part, every circuit with the transfer function G=k/(as^2+bs+c) can be used it must not be necessarily an RC combination but also LCR or a crystal or whatever works. As long you compensate for the linear term "bs" this thing will oscillate sinusoidal.
@goodun6081
5 жыл бұрын
Thorens used a Wein Bridge Oscillator in one of their old belt-drive turn tables, to drive an AC synchronous motor and still be able to have a pitch control and easy electronic speed adjust without having to move the belt to a different motor pulley. This was in the TD 124 or TD 125, I forget which. An excellent turntable if you put a good tone arm on it by the way. Many of the other Thorens turntables weren't all that great (and had flimsy integral tonearms) and the 1980s models with DC motors tended to have speed drift as the motor warmed up or aged; synchronous motors are really much more stable over time.
@Anvilshock
5 жыл бұрын
Pretty sure he used a Wien bridge o, not a Wein bridge o.
@trappy77
12 жыл бұрын
I do not build any circuits like this, but it is great to watch your videos to help me stay up on the theory behind some of these circuits. Keep it up!
@dr.med.schlomov.aschkenasy842
7 жыл бұрын
Thank you!!!!!! So long I wondered why that light bulb. I searched halve the Internet but everyone besides me seemd to understand. You finally explained it so clear and easy. I subscribed and hope to learn a lot more.
@qu1j0t3
7 жыл бұрын
There's a detailed analysis of the Hewlett Packard light bulb Wien circuit by Jim Williams, in the book www.amazon.ca/Art-Science-Analog-Circuit-Design/dp/0750670622
@BOROZ28
10 жыл бұрын
I heard about it before but never thought that it would have such precision for what it is(Simplicity).
@sebastian19745
Жыл бұрын
I never tought the light bulb to be lame in any circuit. Many times it was preffered instead LEDs. Since 8, when I build my first "lab" AF oscillator that was a Wien bridge with transistors only, I many times, used the Wien bridge as a stable and clean oscillator, with opams or transistors or even tubes even in RF (LC configuration with L or C variable). And, at first I wondered too what that bulb is doing there but, after opening the circuit, redrawing it and reading the explanation I understood their role in keeping the circuit stable. Strange is that Internet now (re)discover this circuit. Maybe soon you will find that existed many other configurations of oscillators RC, LC or even RL that were used before digital ones that are today.
@jeriellsworth
12 жыл бұрын
It's a nice unit. I'm still learning all of it's ins and outs.
@ivankand2552
8 жыл бұрын
I'm in love with your brain :) Personally I find it very useful to know the physics of basic materials used in electronics( light bulb filament heats up increasing resistance, etc. etc. ), not only does it help in understanding of how circuits work, it helps you find new implementations as well. P.S. You're such a nerd
@HighestRank
8 жыл бұрын
Incandescents & IR sensors, love the one you're with.
@rvscootin3457
8 жыл бұрын
AWESOME history lesson and throwback circuit design!!!
@suitandtieguy
12 жыл бұрын
wow ... that scope is off the chain. thanks for explaining this.
@CSmyth89
11 жыл бұрын
found that helpful in understanding these a tiny bit more, thankyou
@SameBasicRiff
4 жыл бұрын
Just recently saw the cancelled L4D game using your tech and then this popped up in my recommend. I must say, you are 10/10 amazing!!
@Possumliving
10 жыл бұрын
That is really cool! Linear triumphs over digital, yet again.
@BrightBlueJim
6 жыл бұрын
Or rather, non-linear. When she replaces the (non-linear) light bulb with a fixed (linear) resistor, the performance is greatly degraded.
@craig265
12 жыл бұрын
Lightbulb Idea number one. Banging on-top of the board Idea #1. Time Place Location #1.
@chaosopher23
10 жыл бұрын
It is said that the sound of the vacuum tube is legendary and the most desirable sound. A light bulb can be considered a single-element vacuum tube, so this oscillator is both a hybrid circuit and it has that Tube Sound that makes it so good.
@MattSiegel
10 жыл бұрын
loved seeing the harmonics!
@ahmedalshalchi
6 жыл бұрын
hahaha ... that's meaning non linearity.
@Rouverius
11 жыл бұрын
0:32 I remember a similar feeling when installing 10base2 network cards back in the 90s. There was a neon lamp attached to the BNC. These were for "modern PCs" and they were using something akin to a vacuum tube. Of course, later I found out why; the hard way. Those 10base2 NICs had a chassis ground. One place had bad electrical wiring. When I plugged in the BNC cable, I got zapped with 60 VAC and scared as the neon lamp flashed. But it did it's job as a GDT and saved the PC. Not lame at all.
@AlanCanon2222
2 жыл бұрын
I had the same experience, practically, in 1994, putting 10base2 into an IBM PC AT. Office had reverse-wired neutral and hot. I got a strong jolt. The PC survived but the network card did not. (This with the PC powered off but plugged in to mains).
@ianboard544
5 жыл бұрын
It's not just the non-linearity of the light bulb - it's the fact that it's time constant is long enough that it varies hardly at all over the period of the oscillator.
@JerryBiehler
12 жыл бұрын
Light bulbs are still used in a lot of circuits. I took apart a giant Compaq robotic DLT tape library and the motor control circuits used a whole bunch of small (~50w) quartz halogen lamps in the power supply. Guessing part of the bus voltage shunt to bleed off voltage when the motors are decelerating.
@DeanSegovis
12 жыл бұрын
I love the elegance of this circuit! A light bulb as a thermistor. I remember seeing this one in some op amp circuit books and I too wondered what the hell a light bulb was doing in there. Now I know. :) Great video Jeri... thanks! Keep On Hackin!
@Axelvad
5 жыл бұрын
Great stuff. Its been nagging me to a bit. Thanks
@ThiagoVilla0
12 жыл бұрын
Jeri I just had an oscillators class in Electronics in college and you explain it so much easier than my professor! Hahahaha. Thank you.
@anthonymiller4703
4 жыл бұрын
that was amazing Jeri and entirely simplistic! Thanx 4 the upload
@floretionguru2977
3 жыл бұрын
Mateo Aboy has a video "Wien-Bridge Oscillator: Amplitude Stabilization" which uses two diodes for stabilization. She refers to the lightbulb method as the HP method for obvious reasons :)
@BlisterBang
4 жыл бұрын
I'd kill to get my daughter as interested in electronics as you are. I try all the time to get her into it, and she can hardly wait to change the subject. : ( Keep it up,Jeri!
@centar2001
11 жыл бұрын
WOW!, in 49 yrs I have never ever heard a female speak my language, and so perfectly! You are awesome!
@larry785
Жыл бұрын
My General Radiotelephone tube-type CB radio has a feature called "Tone signal". It sends out a warbling tone to alert others via the transmitter. It uses a wien bridge oscillator with a neon bulb as part of the circuit - no transistors or IC's!
@AppliedScience
12 жыл бұрын
Neat! I've never seen a circuit like that.
@captaincutback
12 жыл бұрын
Thanks for this informative, concise and well produced video.
@kenderosa8528
7 жыл бұрын
Love a lady who knows her wy around an Op amp
@aduedc
2 жыл бұрын
Great idea, that light bulb. Thanks for bring it to our attention. But I guess you can have a pick detector on your oscillator and then adjust the resistor that sets the gain of the oscillator. If C1=C2 and R1=R2 than your feed back factor beta is 1/3, and you need a gain of 3 out of your opamp, which means the ratio of R to Light bulb resistance should be 2. So, using a N type MOSFET biased in the ohmic region and a constant resistor can be replace your light bulb. Now you can make a peak detector and a feedback network to adjust the gate voltage of the NMOS, in order to get low phase noise. This can also cancel out the pushing (frequency change as result of supply voltage change.)
@acmefixer1
12 жыл бұрын
I used a #1869 light bulb from Ratio Snack for a WBO, and found that it was 'microphonic'. The crimps on the ends of the filament were loose, and were ok when it was glowing since the hot filament wire expanded. But when the filament was just barely warm in the WBO, the ends made poor contact. Remember that the lifetime of this light bulb is extremely long because it doesn't get very hot. Thanks for the WBO explanation. I love a female who can talk tech like the guys!
@saarike
7 жыл бұрын
Very nice video! Thanks for information. Very stable oscillation circuit.
@jimedgar6789
10 ай бұрын
Brilliant explanation, thank you !
@AstroZon1
11 жыл бұрын
Thanks Jeri. I'm going to build a Wein Bridge Oscillator and test it through a VCF and VCA. What I liked about your video were the harmonics which aren't usually wanted but are desired for subtractive synthesis. I'll l try it with a thermister and a photocell. BTW, nice scope!
@fgleich
11 жыл бұрын
Great job Jeri, your explanation was concise and to the point. thank you for a great vid.
@sanjursan
5 жыл бұрын
Digital scope with a very, very cool analog pointer!
@kensmith5694
12 жыл бұрын
There is an alternative version with 2 op-amps that gets around the fact that the common mode rejection ratio of most op-amps is quite non-linear. The theory of opperation is the same. The second op-amp gets the RC circuits and drives what in your circuit is the ground end of the lightbulb. It does about a decade better on the distortion values. This makes it good enough for testing audio circuits.
@jamesmasonic
8 жыл бұрын
You dont always need an Opamp for this. You can also do it with 2 transistors and some caps and resistors. I think it was done with two transistors before Opamps came.
@jeriellsworth
12 жыл бұрын
We might do that soon. This was filmed in the Valve lab.
@wease1
12 жыл бұрын
Excellent documentary, Jeri! I never knew why they'd use incandescent bulbs either, until now :) It reminds me of the use of 250V neon lamps as surge arrestors..
@video2k007
12 жыл бұрын
Very nice vid, thanks! Fun to see the spike at 2:45. :) Greetings from Wien (Vienna) :)
@oneillkza
11 жыл бұрын
A guy I know exploited the same property of a light bulb (increasing resistance with increasing current) to make a guitar compressor effect (just by wiring it in series between the guitar and amp). The cool thing is that it lights up when you play hard enough. If you wanted to do it yourself, I'd probably add a pot, though, since guitar pickup voltage output apparently varies by quite a lot from pickup to pickup.
@poochie1480
5 жыл бұрын
Was admiring her all the time but I can always rewind
@danmyself5341
7 жыл бұрын
my, we have similar history, and today I'm a full time inventor, cheers
@jimmygizmo
2 жыл бұрын
Thanks for the great video. I learned a lot in that 5 minutes!
@mikefromspace
9 жыл бұрын
One thing I didn't see mentioned here which I think should have been is resonance. The diameter of the bulb filament winding relative other parts is critical in some cases because of charge transition from part to part. This will help you prevent making those pesky artifacts for one, or you can apply such knowledge to making the first basic faster than light transmitter which used a heater coil (it's patented, search it). The key is physics, geometry, and ultimately the flower of life pattern which if used as a gauge for resonance among differing radius points, will also give you knowledge on predictive circuit building so it comes out right the first time. Eliminating thermal curve between caps of any kind (everything is a cap to some degree) will prevent burnouts and make cleaner waves.
@robertbilling6266
5 жыл бұрын
We did this as a lab in Cambridge. We were given the components, and allowed to make any measurements we chose. Then we had to predict the frequency and voltage of the output. After that we built it and measured the output. My prediction was pretty close.
@hsilva44
11 жыл бұрын
Great technical explanation! Thank you, Jeri.
@jcost0099
6 жыл бұрын
That "out of control in gain and harmonics" is the corner stone of electric guitar fun... don't kill it! lol
@suyashkumar1927
4 жыл бұрын
I think its like a limit cycle thing. Most oscillators do rely on non-linearity for oscillation. Somehow, the non-linearity of the bulb is compensating the pole movement caused by shifting power supplies.
@RexxSchneider
Жыл бұрын
No. The Wien bridge shown requires 1/3 of the output voltage fed back to the non-inverting input to maintain oscillation. The light bulb's resistance increases as the voltage across it increases (i.e. it heats up), so there will an output voltage where the bulb's resistance is half that of the feedback resistor. That is a stable condition because if the output were to increase, the voltage across the bulb would increase and lower the gain, thus decreasing the output, and vice-versa. So the output level depends only on the voltage required to make the bulb's resistance half that of the feedback resistor and therefore essentially independent of supply voltage or other factors. Past a few tens of Hz, the frequency is irrelevant.
@frank083
12 жыл бұрын
Excellent video! Quality content, clear, concise, and useful!
@Pandakaniya
6 жыл бұрын
Well I had to watch this video for 2 times. First time at her beautiful face Second time understanding what she explains Keep it up
@Anvilshock
5 жыл бұрын
creep
@andyrofl
12 жыл бұрын
Jeri I've been following you on twitter for a while and usually have no idea what you are talking about, but lately some of it makes sense.
@gyrgrls
8 жыл бұрын
It's just a filament of your imagination. But seeing you inspires me to build an osculator.. Anyone who molests power supplies is fixated on the rail, leading to a one-track mind. But you wreck my train of thought. I need distortion in my next project, which is an electric harmonica.
@rougenaxela
12 жыл бұрын
If you're speaking in general terms, there are materials which work either way. Some become more conductive with temperature, and some become more resistive. Look up NTC and PTC thermistors and the difference between them for more info.
@ChrisBrooker
5 жыл бұрын
Great insight, thanks Jeri!
@ingussilins6330
Жыл бұрын
Lightbulb between power supply and LM317 ,LM78xx can made easy constant current, constant voltage linear regulator for charging batteries.
@azzym312
8 жыл бұрын
Jeri, you could discuss the fact that the oscillator is not always stable and any change in frequency for example causes the amplitude to ripple for some time before it settles at a new value.
@joyange1
12 жыл бұрын
Did you know that a light bulb connected in series with a speaker and the amp output will work as an automatic gain control. as the filament get hotter,the resistance goes up. Crosley, Who was a radio pioneer of the 1930s, designed a radio that use a light bulb for AGC. It was called the expressinator tube.
@BarsMonster
12 жыл бұрын
It's good to finally see Jeri again :-) Please make more of it :-)
@KeritechElectronics
2 жыл бұрын
Great insight on a tiny non-linear resistive element :) I wonder about choosing the right parameters (nominal voltage and cold resistance; resistance-temperature characteristics) when designing the oscillator. Maybe Mr Carlson has something to say about it?
@dale116dot7
11 жыл бұрын
That or any other diode-based 'clipper' will work and I've done it too but the THD specification will be worse than the light bulb, provided that the light bulb has a time constant that is a lot longer than the output frequency.
@PileOfEmptyTapes
12 жыл бұрын
Low-distortion oscillator design seems to be some fun stuff indeed. If anyone's interested, one example is to be found in the first of Cyril Bateman's "Capacitor Sound" articles that you can dig up someplace on the web. The problem of the circuit demonstrated here is that it apparently runs its OP at single supply between +Vs and ground, with a ground-referenced +in. Might work with an LM358, but not with most OPs. Better get +in DC to about +Vs/2, as suggested by kubarebo.
@robertneill3057
2 жыл бұрын
Could also try the more expensive PMOS CA3140. Also available is the CA3240 dual PMOS op-amp. For frequencies higher than audio the slew rate of the op-amp used becomes an important factor.
@j.j.springer1099
8 жыл бұрын
we use 6 light bulbs in series to check a 480v AC 3 phase input to a 500 volt dc motor drive. hook the lights to the leads going to motor ,which is disconnected. turn the controls up watch the light to see if it's safe to use the circuit with the motor. if your wrong you don't destroy the motor drive and can go back and fix. used mostly switching out blown SCR's and fuses that blow when the guys over load the motor
@HighestRank
8 жыл бұрын
Take good care of those incandescents, law wants them dead or alive.
@j.j.springer1099
8 жыл бұрын
+Rýán Túçk retired now. who knows where they ran off too
@spfjpm
7 жыл бұрын
I have no idea what I'm doing, very interested in understanding electronics, and how silicon plays a role. what do I need to buy and read to get started in making my own electronic components? Love your videos, thank you
@spfjpm
7 жыл бұрын
mainly interested in transistors, and how to crystallize materials play a role
@guanglier
11 жыл бұрын
very nice video ! i really like old circuits !
@xanataph
8 жыл бұрын
Yeah, I used to think such "outdated" components were lame when in my younger days too...but since then I have developed an appreciation for Steam Punk styles...! ;) Which has sorted of resulted in using filament bulbs in place of fixed resistors anywhere even the slightest advantage can be gained by doing so. lol They have the added benefit of also being an indicator so you can gauge what is going on. If you want a non-linear resistor that can handle much more power than a bulb, steel is also useful in this regard....Good ol' #8 wire...!
@dedskin1
8 жыл бұрын
+xanataph or you just started listening rock music and watching mad max , and bam, lamps everywhere :) i like old components too im just doing restoration of 50 year old record player with amp, but i dont like those old dead bug designed's ...there is nothing to appreciate there
@John-pp2jr
2 жыл бұрын
Nice clear explanation.
@Cheefrocco
7 жыл бұрын
Jeri, you are the sweetest thing! I love your gear, my God, the Tektronix! Your looks, they remind me of Elizabeth Mitchell.
@Deckardsvr
12 жыл бұрын
interesting stuff ! thanks Jeri
@morpher44
12 жыл бұрын
Really well done. Your videos are so much better than learning this from some book.
@Lidmotor
12 жыл бұрын
That was wonderful! Good to see you doing these kind of videos again. The BEST part of this one was your "little helper". I gotta make one of those. The circuit was pretty cool also. Just kidding. I never knew that a light bulb in a circuit was doing what you showed. Thanks.
@hpux735
12 жыл бұрын
I feel like that would be the ultimate tool to diagnose complicated RF modulators and demodulators. It has been on my amazon wishlist for months, but I don't think anyone's going to get it for me for xmas ;p
@TerminalJack505
12 жыл бұрын
I always wondered why they used a light bulb in that circuit. Now I know. Thanks.
@danzilcho8385
11 жыл бұрын
I really admire you,self taught!! You are an inspiration!
@Nichetronix
10 жыл бұрын
I understand the movie "Fantasia" actually has that Wein bridge oscillator from HP in the soundtrack.
@wdeekpotter3917
9 жыл бұрын
I have one of the early HP oscillators and it does indeed have a light bulb in it.
@MichaelAChang
12 жыл бұрын
My friend has a collection of old HP products and yes, the old Wien Bridge is quite interesting. There's a write-up on the HP8903 distortion analyzer from the 80s in an old issue of the HP Journal, well worth reading to see how analog oscillators have evolved. By the way, ever seen distorting resistors caused by its voltage coefficient? You see these things when you build oscillator/analyzers down to a few PPM nonlinearities.
@pmgodfrey
11 жыл бұрын
I think I have the same meter that you have sitting there in the background. Love that meter. I just watched your scanning electron microscope video -- very cool...I'm very jealous. :)
@themaconeau
12 жыл бұрын
".. I was just reminiscing about when I was a kid and I would get books about OpAmps." Has anyone mentioned that you rock already? :P :D
Пікірлер: 507