Programming an Analog Computer

A brief demonstration of programming an analog computer.

[VoidHalo]

Hey Tim. I just wanted to say, I still come back to watch these videos once every few month to a year. Most people don't realize you miss/forget a LOT from a video just watching it once, you're never gonna retain all of the information in these gems from just one viewing. So I'm still learning stuff from them after about my 4th viewing. And each time makes me wanna make my own lol. If I focused I could probably design and build a digital computer without an CS degree, but I think analog's a bit beyond me. Especially not being too strong in calc. Either way, I wanted to thank you for taking the time to make and share these videos. And for taking the time to address my comment several years ago about the floating inputs. It's nice to see you're willing to give us little folk the time of day. Hehe. Anyways, cheers, buddy. I wish you all the best!

[QuasarRedshift]

I never thought that I would ever see this on you-tube; amazing! Great job and please keep it up

[SenatorMailman]

Hello, Mr. Thompson. This video is very insightful. As a programmer from the digital era that did not prioritize mathematics during college, this is eye opening.

I should inform you, it seems more people will find your videos soon. This field may become more robust soon. Have a great weekend.

[hrnekbezucha]

This is way over my head but it's just fascinating. Programming some more complex problem must take a massive amount of effort. It looks like you would be better off with a pen and paper. That is if you don't need a continuous result. Or tweaking a parameter or two without having to recalculate everything again.. Using op-amps for calculation and getting a result in voltage. My mind is blown.

[poly_hexamethyl]

This reminds me of when I was in grade 6 I made an analog multiplier/divider out of 2 potentiometers and a meter. Good times!

[suitandtieguy]

Great video, thank you. I came here because I design and build modular synthesizers and was exploring "soft boolean" functions with transistor logic gates, among other things like sequencers that are under 3-bit address control.

[Turd_Ferguson]

I had a lot of trouble following along due to math being my weakest subject but I was enthralled nonetheless by this demonstration. Thank you for putting this on YouTube!

[VoidHalo]

You should ideally never leave the inputs or output of an op amp floating, even in a voltage follower configuration with negative feedback like you've done because it will saturate the output and lead to damage or excessive current consumption, and gradual degradation.

Texas Instruments has a great application note on properly terminating unused op amps. It's meant for ICs, but I'm sure the theory applies just the same to any op amp, regardless of how it's made. The application note is called How to Properly Configure Unused Operational Amplifiers and the document number is SBOA204A. You can find it easily enough on Google. I'd always been terminating unused op amps wrong for years until I came across this.

It may be different with an analog computer, but I thought I would mention it anyways because I would hate to see such a beautiful piece of kit get damaged. Thanks for taking the time to share this with us. It's really great to be able to see an anaolog computer running like this. Cheers.

[baltofarlander]

Kinda lika modular synthesizers (which are, in some sense, analog computers)

[Enigma]

It seems like it wouldn't be too difficult to build one one of these from a bunch of op amps, pots, and such.

[synthoelectro]

I write avant-garde music and your way of explaining this presentation would be perfect for a song in the future I may write.
Is it ok if I add your voice to that song?

[companymen]

I wonder if the fetch-decode-execute-write back paradigm of current processors can be applied to this. An analog co-processor to digital processors.

[smith]

Analog Neural Networks have been shown to recognize text up to 96% certainty.

[Muck-qyoo]

I would like to see how you program graphics on an analog computer. How do you draw circles and sinus waves, cars and so on.

[CaseyVan]

Isn't analog theoretically faster than digital?

[avavanderzwan]

are you still around, can you reply to this if youre able to help me with a problem starting in analog, i have all the eqp. i beginning to suspect my computer is malfunctioning

[jessstuart]

Why did you use an acceleration of -0.161? Your scale factor will be 200ft/V. Using -0.322 V (32.2 ft/s^2) is much more convenient because your scale factor (100ft/V) can be applied by just shifting the decimal point two places.

You will have to multiply the output voltage by a factor of 200 to get back to feet again. The time-base scales by a factor of 400. (1 time constant "analog computer time" = 2.5ms real time)

Do you know how well the precision resistors (50k) and capacitors (50nF) have aged? Are there trim pots and caps inside that allow for readjustment or "calibration" ?

[LonewolfeSlayer]

Is there a way you can list all the books in the background?

[ribamarsantarosa]

WOW!! Could these analog computers from the 50's and 60's multiply/divide numbers? I mean, digital computers can't compute really well things like 10*0.1....

[arthurharrison]

Are the operational amplifiers made form discrete transistors, or are they integrated circuits?