I think ramping up the supply voltage a little bit (to like 6 volts) could potentially solve the diode voltage drop issue, but it may also increase the power draw and heat generation and also potentially wear out the relays faster. But i do like the calculator, and i may build a transistor calc at some point, using the same one-by-one addition technique. Cool stuff!
I've been enjoying your videos, so much so that I've been watching some of these older ones. I'm a little confused about the diode drop problem as you illustrated it on the breadboard. If these are oring diodes why not just send each signal to be ored into the anode of an individual diode and join all the cathodes together? This way there's only one diode drop, no matter which input fires. Thanks, Mike.
Before ever looking at yours or anyone's stuff, I kind of fumbled around and invented some of this stuff on my own. Based on this, I have a couple of observations: 1. Strictly speaking, your 'inverter' is not quite right. The problem is, you have 2 states: ON or 'floating', whereas it should be either ON or OFF. This is quite a useful behaviour when you need 3 states for driving data buses etc. This may or may not be a problem for your design however, to have ON or OFF logic, you should do the following: 1. flip the relay around 2. the 2 'outputs' are now connected directly to VCC and GND 3. one of the coil pins becomes the 'input', the other coil pin goes to GND 4. the 'input' pin now becomes the single pin 'output', which is either VCC or GND 2. A simple way to understand XOR: I first imagined one of those '2 way' circuits you find in house wiring, where you have a switch at the top of the stairs, and one at the bottom. Flipping either switch will turn the lights ON or OFF. This circuit consists of 2 SPDT switches connected back to back like this: qph.fs.quoracdn.net/main-qimg-e0a493f34e0f10f616995a132fafd72f Of course, this circuit describes XNOR logic. i.e.: downstairs upstairs lights OFF OFF ON OFF ON OFF ON OFF OFF ON ON ON To make an XOR gate therefore, all one needs to do is have these 2 back to back relays, then add an inverter. 3. I love your explanation of the problems with diode OR gates. I needed a 12 input OR gate in one of my (not relay) projects, so I used 12 Schottky diodes as this seemed like the simplest solution. It should be noted however, that this method has the same issue as my first comment (i.e. ON or 'floating' logic.) This could be solved with transistors, but of course this would defeat the whole point a relay circuit, so probably in your case, relay OR gates might have been a better fit than diodes.
Thank you! You know, our house is filled with those "2-way" light switch circuits, with one switch on one side of the room and one on the other, and it never dawned on me that those were essentially XNOR gates! That's a really brilliant way of looking at it! For my design, you're right that I never actually pull an output low, it just goes floating (or disconnected from everything). Fortunately, that wasn't ever really a big problem for these simplified designs, but I can definitely see how if the complexity grows, that could cause potential issues! Definitely keep me updated on any progress on your relay designs! There's not nearly enough people out there experimenting with relay based computing stuff, so I'm super interested to see what you come up with!
@@UsagiElectric Have you taken a look at Ben Eater's site? ruclips.net/video/HyznrdDSSGM/видео.html He has an absolutely awesome 8-bit computer build (40+ videos) using 7400 series chips, all done on breadboards, where he explains every aspect in glorious detail. Anyone who still thinks that computers are magic, needs to watch his series. I may try to duplicate his project on an FPGA ... this would be interesting too. The funny thing is, even though there's a huge gulf in sophistication between relays and FPGAs, the fundamentals are exactly the same. If you can do one, you can do the other. As you suggest, it is extremely important that people do these kinds of builds. This is really complicated technology. We need to stay on the cutting edge. And the only way to REALLY understand this stuff ... is to do it. Also, I feel kind of bad for you, because you have obviously gone to an ENORMOUS amount of effort and expense, and you've put a huge amount of effort into your videos ... yet you aren't getting a lot of hits. Really, you deserve a LOT more attention. I suppose this is in part because most people would rather just blink LEDs with their Arduinos. Still, there are many people out there who really appreciate this kind of content. You might consider contacting some of the more popular channels and let them know what you've done. I'm sure they'd be happy to throw a bit of attention your way.
@@RUclipsBorkedMyOldHandle_why I have indeed seen Ben Eaters stuff, and his videos were actually a huge inspiration to start making videos of my own too! I think I've watched every video of his about twice by now, haha. Another amazing channel and 8-bit build to check out is James Sharman's build: ruclips.net/user/weirdboyjim James is building an 8-bit pipelined CPU, he starts on the breadboard and moves it onto PCBs later, but it's one of the most in depth series I've ever seen on the inner workings of a fairly complicated processor. Plus, I've talked with James a few times, and he's genuinely an excellent gentleman! Thank you for the kind words on the channel! The stuff I cover is pretty niche, so I get why the channel hasn't experience growth like other channels out there, but honestly, it's fun to make the videos and the tight schedule really forces me to work on my projects instead of letting them languish in the "one of these days" pile. Most importantly though, the community of people that have gathered around the videos have been amazing! I've never gotten any bad or negative comments and the Discord channel is alive with people sharing projects and knowledge. The people and viewers have been absolutely amazing, which makes it all worth making the videos!
I think ramping up the supply voltage a little bit (to like 6 volts) could potentially solve the diode voltage drop issue, but it may also increase the power draw and heat generation and also potentially wear out the relays faster.
But i do like the calculator, and i may build a transistor calc at some point, using the same one-by-one addition technique.
Cool stuff!
I've been enjoying your videos, so much so that I've been watching some of these older ones. I'm a little confused about the diode drop problem as you illustrated it on the breadboard. If these are oring diodes why not just send each signal to be ored into the anode of an individual diode and join all the cathodes together? This way there's only one diode drop, no matter which input fires. Thanks, Mike.
Before ever looking at yours or anyone's stuff, I kind of fumbled around and invented some of this stuff on my own. Based on this, I have a couple of observations:
1. Strictly speaking, your 'inverter' is not quite right. The problem is, you have 2 states: ON or 'floating', whereas it should be either ON or OFF. This is quite a useful behaviour when you need 3 states for driving data buses etc. This may or may not be a problem for your design however, to have ON or OFF logic, you should do the following:
1. flip the relay around
2. the 2 'outputs' are now connected directly to VCC and GND
3. one of the coil pins becomes the 'input', the other coil pin goes to GND
4. the 'input' pin now becomes the single pin 'output', which is either VCC or GND
2. A simple way to understand XOR: I first imagined one of those '2 way' circuits you find in house wiring, where you have a switch at the top of the stairs, and one at the bottom. Flipping either switch will turn the lights ON or OFF. This circuit consists of 2 SPDT switches connected back to back like this:
qph.fs.quoracdn.net/main-qimg-e0a493f34e0f10f616995a132fafd72f
Of course, this circuit describes XNOR logic. i.e.:
downstairs upstairs lights
OFF OFF ON
OFF ON OFF
ON OFF OFF
ON ON ON
To make an XOR gate therefore, all one needs to do is have these 2 back to back relays, then add an inverter.
3. I love your explanation of the problems with diode OR gates. I needed a 12 input OR gate in one of my (not relay) projects, so I used 12 Schottky diodes as this seemed like the simplest solution. It should be noted however, that this method has the same issue as my first comment (i.e. ON or 'floating' logic.) This could be solved with transistors, but of course this would defeat the whole point a relay circuit, so probably in your case, relay OR gates might have been a better fit than diodes.
Thank you!
You know, our house is filled with those "2-way" light switch circuits, with one switch on one side of the room and one on the other, and it never dawned on me that those were essentially XNOR gates! That's a really brilliant way of looking at it!
For my design, you're right that I never actually pull an output low, it just goes floating (or disconnected from everything). Fortunately, that wasn't ever really a big problem for these simplified designs, but I can definitely see how if the complexity grows, that could cause potential issues!
Definitely keep me updated on any progress on your relay designs! There's not nearly enough people out there experimenting with relay based computing stuff, so I'm super interested to see what you come up with!
@@UsagiElectric Have you taken a look at Ben Eater's site?
ruclips.net/video/HyznrdDSSGM/видео.html
He has an absolutely awesome 8-bit computer build (40+ videos) using 7400 series chips, all done on breadboards, where he explains every aspect in glorious detail. Anyone who still thinks that computers are magic, needs to watch his series.
I may try to duplicate his project on an FPGA ... this would be interesting too. The funny thing is, even though there's a huge gulf in sophistication between relays and FPGAs, the fundamentals are exactly the same. If you can do one, you can do the other.
As you suggest, it is extremely important that people do these kinds of builds. This is really complicated technology. We need to stay on the cutting edge. And the only way to REALLY understand this stuff ... is to do it.
Also, I feel kind of bad for you, because you have obviously gone to an ENORMOUS amount of effort and expense, and you've put a huge amount of effort into your videos ... yet you aren't getting a lot of hits. Really, you deserve a LOT more attention. I suppose this is in part because most people would rather just blink LEDs with their Arduinos. Still, there are many people out there who really appreciate this kind of content. You might consider contacting some of the more popular channels and let them know what you've done. I'm sure they'd be happy to throw a bit of attention your way.
@@RUclipsBorkedMyOldHandle_why I have indeed seen Ben Eaters stuff, and his videos were actually a huge inspiration to start making videos of my own too! I think I've watched every video of his about twice by now, haha. Another amazing channel and 8-bit build to check out is James Sharman's build: ruclips.net/user/weirdboyjim
James is building an 8-bit pipelined CPU, he starts on the breadboard and moves it onto PCBs later, but it's one of the most in depth series I've ever seen on the inner workings of a fairly complicated processor. Plus, I've talked with James a few times, and he's genuinely an excellent gentleman!
Thank you for the kind words on the channel! The stuff I cover is pretty niche, so I get why the channel hasn't experience growth like other channels out there, but honestly, it's fun to make the videos and the tight schedule really forces me to work on my projects instead of letting them languish in the "one of these days" pile. Most importantly though, the community of people that have gathered around the videos have been amazing! I've never gotten any bad or negative comments and the Discord channel is alive with people sharing projects and knowledge. The people and viewers have been absolutely amazing, which makes it all worth making the videos!
Sir Can We Have The Schem?