'Universal' IO - Page 1
Forum section: electronics / projects

author: mr_darker
author_rank: Contributor
timestamp: November 13, 2018, 04:59:21 am
content: So I've got a bit of an ambitious project, and the short explanation is it's a terminator.I'd like to discuss the electronics though, just assume all the mechanical parts work and are made already.I'm not really sure exactly what I'm looking for, just opinions or suggestions that aren't from my own mind. Different perspectives, from people who are actually capable of doing the work themselves, educated opinions.The power unit I have in mind, is actually 3 parts. Power Input, Power storage, and IO (Data IO and/or power output, or power input that's routed to the Power Input stage).The input part I want to be able to power the robot, anything from a 5v power source (slow charge), to 220vAC outlets, DC, AC, you name it. HUGE input range, HUGE power input as like... 50+ stepper motors at 3 or 4 amps each, at like 60 volts each, that's like 12kW if everythings at full power all at once. Not sure of the requirements so I'd just like it to be capable of that. So like... 0-400v (once rectified) input, with current control so that the the thing doesn't try pulling more amps than say a 15 amp 120v outlet can supply. Not sure how hard it'd be to achieve that input range, but the output voltage should be 170vDC. Also it has to be small, and so I was thinking the best topology (not a SMPS expert, new to it) would be an LLC Resonant converter working at the highest frequency I could achieve, liquid cooled n all that.The storage stage, takes that pool of 170vDC and turns it into the 3.2 volts or so that the super capacitors need, and vise versa. Not sure if this would be two separate converters, or if a single power converter topology exists that is bidirectional, where it can charge the capactiors (or battery) and then decide to switch and start sourcing power from them in the other direction. Not sure what topology would be ideal here, has to be small of course, and capable of massive amps, as the 12kW unit (most likely overkill) would have 4000 amps in a scenario like that at full load. I have a feeling it only needs a small fraction of that power, but the maximum motor current on all 50 motors is an easy way to get some variables to start designing things off of.The output stage, this isn't really just a power converter, and is kinda a complex device on its own. There will be 50+ of these. I want each to take in 170V, and step it down (individually) to whatever voltage it is programmed for. Aware of the safety hazard that poses, making a device that can put out 5 volts but accidentally put out 170, I'd like to focus on reliability and safety. I want very high resolution control over the voltage, and current control too. I can't remember if it was 10 amps per output or 5, i think i lowered it to 5. Tri-State outputs (guess i should be calling them IO ports). Basically they can act as power, and/or signal ports, universal you could call it, that's the aim. Digital signals for sure, analog i feel is a bit of a stretch, though it should be able to put out a sine wave to simulate AC, and that's where we get the 170volts, makes it easy to put out 120vac, or hook two of them up and adjust the phases so it's 220vac. Or use the same exact hardware, programmed to hook up to a usb port on a computer and transmit some files, then have the same exact hardware hook up to a car battery and if possible, be programmed to route however many amps that port can handle, through to the power input stage i first mentioned in this post. You know, universal is the aim. Doesn't have to be the absolute best, just do it all and do it all as best as it is possible to while being so flexible. Any super special/rare applications can jsut get an adapter added onto the end of the thing.So in short, you put any voltage in, even on the output side (i imagine this would always be less efficient), have mobile power reserves, and a ton of universal io ports that can do just about anything. 0-400V 12kW input, storage, and a sort of universal io configuration that will output 0-170vDC (or 0-120vAC), or take that in and route it to the input stage so the energy goes to the 170V pool, all current controlled whether it an input or an output. Preferably analog capability too but that might be a bit much without significantly increasing the cost per unit. Each IO individually programmed with its own voltages and io configurations.Sound doable? Loads and loads of work? Piece of cake except this bit and that bit? Wishful thinking? Just wondering what others think. Don't have much free time, so I don't want to waste too much time designing something that turns out to be a waste of time. Never designed a power supply before, so forgive me if it's disgustingly all very very wrong lol.