Truly one of the most elegant implementations of all the basics that one could ask for.
In case you haven't dug into this dear reader, the Lunar Lander example is fascinating! Takes a bit of patience to set up, but is truly fun.
I'm left wondering at what other kind of hijinks a real, life-size ANALOG THING could be pressed into executing .. in a general sense I've always had a personal fascination with analog computers in other shapes and forms - pinball machines, electronic music synthesizers, the flowerbed - but like most I suppose, have spent nearly all my life attached to a digital one, in some way or another.
As I see it, a gravity/water-based analog thing is doable, and .. one fine Sunday afternoon, might be the perfect thing to design/prototype with whatever ML model will be waking up for some pushing around.
If there were, say, an electromagnetic means of tracking the state of a pinball as it traverses the playfield, and of course if the drop targets and bumpers and switches and flippers and things were all appropriately wired up, I wonder what it would take to program an analog computer thing to play a mean pinball...
That (electronic) analog computers have integrators is, as I have read, the whole reason analog computers existed—stuck around. Integration is ideal for simulating forces like gravity, etc. over time.
Early experimental X-planes (like the X-15, for example) had flight simulators that were completely analog—modeling the forces of lift, etc. (In the 1970's, there was even a commercial analog flight simulator sold [1].)
I took a deep dive for 12 months on how analog computers work(ed) and the result was a little kit and book that represent a kind of analog computer primer [1]. In short I took what I learned over the year and made something that would fast track others (you can probably go through the manual + kit in about two weeks and know as much as I do now).
I had originally wanted to get one of those Analog Things but was a little put off by the price (so of course I spent close to an order of magnitude more to develop my own analog computer).
Lower left, "-1/+1" are your source voltages representing the smallest allowable value (-1) and largest (+1).
Upper left "COEFF" are the coefficient multipliers—potentiometers, that take a voltage (value) in (circle) and output (triangle) and attenuated value/voltage. You change the potentiometer values with the "COEFFICIENT POTENTIOMETERS" section on the right side of the split view.
The top section of the analog computer represent the all-important "INTEGRATORS" (5 of them). Circles are inputs (a 1x and 10x) and the output is the triangle.
A lime green wire connects from the +1 source voltage to the #1 coefficient multiplier, that attenuated voltage/value feeds "IC" on the first integrator. IC represents the initial condition of the integrator—the value/voltage it defaults to when the machine is reset.
That first integrator's output (triangle) is being fed into a second coefficient multiplier where the output from that is fed back into the input of said integrator. In short, the integrator is feeding back a portion of its output back into itself.
Another wire (purple) from that integrator is goes first to in inverter n the "INVERTER" section (probably obvious what this operator does) and then connects to the "X" of the "OUTPUT" section. The oscilloscope is displaying "X" on "CH1" (channel 1). We see the decaying voltage/value of the integrator on the oscilloscope.
(Please let me know if I got something wrong here.)
13 comments
[ 3.3 ms ] story [ 24.9 ms ] threadIn case you haven't dug into this dear reader, the Lunar Lander example is fascinating! Takes a bit of patience to set up, but is truly fun.
I'm left wondering at what other kind of hijinks a real, life-size ANALOG THING could be pressed into executing .. in a general sense I've always had a personal fascination with analog computers in other shapes and forms - pinball machines, electronic music synthesizers, the flowerbed - but like most I suppose, have spent nearly all my life attached to a digital one, in some way or another.
As I see it, a gravity/water-based analog thing is doable, and .. one fine Sunday afternoon, might be the perfect thing to design/prototype with whatever ML model will be waking up for some pushing around.
If there were, say, an electromagnetic means of tracking the state of a pinball as it traverses the playfield, and of course if the drop targets and bumpers and switches and flippers and things were all appropriately wired up, I wonder what it would take to program an analog computer thing to play a mean pinball...
Early experimental X-planes (like the X-15, for example) had flight simulators that were completely analog—modeling the forces of lift, etc. (In the 1970's, there was even a commercial analog flight simulator sold [1].)
[1] https://inspire.eaa.org/2022/02/16/eaas-attic-atc-510-person...
I had originally wanted to get one of those Analog Things but was a little put off by the price (so of course I spent close to an order of magnitude more to develop my own analog computer).
[1] https://www.tindie.com/products/jcalhoun/anna-analog-compute...
Lower left, "-1/+1" are your source voltages representing the smallest allowable value (-1) and largest (+1).
Upper left "COEFF" are the coefficient multipliers—potentiometers, that take a voltage (value) in (circle) and output (triangle) and attenuated value/voltage. You change the potentiometer values with the "COEFFICIENT POTENTIOMETERS" section on the right side of the split view.
The top section of the analog computer represent the all-important "INTEGRATORS" (5 of them). Circles are inputs (a 1x and 10x) and the output is the triangle.
A lime green wire connects from the +1 source voltage to the #1 coefficient multiplier, that attenuated voltage/value feeds "IC" on the first integrator. IC represents the initial condition of the integrator—the value/voltage it defaults to when the machine is reset.
That first integrator's output (triangle) is being fed into a second coefficient multiplier where the output from that is fed back into the input of said integrator. In short, the integrator is feeding back a portion of its output back into itself.
Another wire (purple) from that integrator is goes first to in inverter n the "INVERTER" section (probably obvious what this operator does) and then connects to the "X" of the "OUTPUT" section. The oscilloscope is displaying "X" on "CH1" (channel 1). We see the decaying voltage/value of the integrator on the oscilloscope.
(Please let me know if I got something wrong here.)