Random Number Machine
This is one of the shorter videos I mentioned I was working on a few weeks ago. It's a look at a random number generator that uses Nixie tubes.
The ebay advert for this suggested that the buyer could gut it for the tubes. When I read that, I decided that I had to rescue this unusual little piece of history.
Comments (22)
I'm curious if you tried setting the high number lower than the low number? And if so, what happened? Although, you're still alive, so I assume you didn't.
It doesn’t do anything, until you give it a range it can work with. Pressing the button does nothing.
This actually makes me wonder... As far as I understand it, a computer can only generate "pseudorandom" numbers because it still is deterministic and has limited capacity/resolution/computing power. But can anything be *truly* random when it seems that even the universe seems to have some kind of "resolution" (e.g. elementary particles, pre-defined energy levels of atoms etc.) Theoretically, if you knew the whole state of the universe at the moment the Big Bang started, I guess you would be able to predict every future state of the insanely big (but still finite) universe. So is there such a thing as "completely random" or is the best we are ever going to get "random enough for all intents and purposes"?
The random component is the button and the human who presses it. If you would replace the button with a solid state relay (PhotoMOS optocoupler) that is controlled by a comparator that compares the AC line voltage to a voltage set by a potentiometer you could actually make the counter stop in a certain area. It would basically become an analog to digital converter. However as a human you are not able to let go of the button at a specific time syncronized to the power line AC. That "flaw" makes it generate random numbers.
Edit: After closer inspection the design is more different than I thought at first. Read my later response below. Original post: If this thing works like the gadget you could DIY based on an Elektor electronics magazine article back in the day it will need one full pulse (3 counts) of the lowest bit. It uses AC voltage from the transformer that is put on a capacitor when you press the button. When you release the button the capacitor is disconnected and now has sampled this "random" voltage of the sinewave and holds it. Since humans can't control when to let go within 10ms the result is kind of random. The counter starts, and the CA555 timer also starts charging a capacitor until it reaches the same voltage your sample & hold circuit has stored. At that point it stops the counter until everything starts over.
This is another occasion where I’ll have to bow to your superior knowledge on this subject.
Genuinely picked 98, jackpot!
77. How do you make such things so interesting to watch - impressed again.
I don’t think that this was one of my best, it was in hindsight perhaps too simple a device to cover. However it allowed me to get a week ahead and that meant that last weeks video had the comedy outro added on to it (it was show a couple of weeks later). This was the last of the really simple videos, the first couple of videos in April are pretty good.
Damn it, 89.
So close, I picked 97
This thing is pretty fascinating, especially on an electrical level, for something from 1978, makes me wonder how truly random it actually is. Would love to see someone do a reverse-engineer and schematic of the electronics (thinking BigClive or EEVBlog or similar), since I'm sure it'd be pretty easy to recreate it using 7-segment LED displays instead of Nixie tubes, and might make for a fun learning electronics project.
So many technical surprises and features inside and out. Classic Techmoan video, thanks for shedding light on this!
Mat: Using this forum to make a request (sorry!): I'm interested in feeding the output from my laptop's sound card to my component stereo system ... a desire I suspect many of your viewers share. Would you please think about reviewing some USB DAC preamp devices? Many thanks for your consideration!
A USB DAC would be bypassing your laptop's sound card (probably a good idea) rather than utilizing it.
What surprised me was I had never considered what RS actually stood for.
What a strange and rather lovely piece of kit. It would have been a crime to simply gut it for the Nixie tubes.
Came to post literally the same sentence, so I'll just +1 that one! This thing is the perfect combination of cool, vintage and awkward!
So this was a way to look at BOOBS before the internet. :-)
I think you're spot on with the raffle purpose. I can picture people using it live on the radio to draw a winner for instance. :)
Very interesting :) according to one of the Brady Haran channels (it was either Computerphile or Sixty Symbols), random number generators are necessary in some labs that require samples of numbers that aren't influenced by human attempts at picking random ones (which always falls into similar patterns, like how people most often pick 7 if they're asked to pick a number between 1 and 10). However it pretty much is prevented by the laws of physics and computers to use a computer to pick an actual random number and so they call the best thing they can do "pseudo-random" numbers. However there's certain ways to get genuinely random numbers, if i recall correctly things like measuring radioactive decay of particles. But for most studies, pseudo random numbers are sufficient. Edit: found the video on random numbers, it was actually a Numberphile video <a href="https://youtu.be/SxP30euw3-0" rel="nofollow noopener" target="_blank">https://youtu.be/SxP30euw3-0</a>
In my previous job back in the 80's our lab had to perform random sampling for quality control purposes. Rather than having something as grand as the nixie generator baches were picked using the (rand) function in Microsoft Excel. I suppose the pseudo random numbers this could generate did away with the need for a dedicated piece of hardware.