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Post by solipsistnation on Jan 14, 2024 17:10:04 GMT
Okay, so let's say I had a 5V 3A regulated power supply.
Is there a reason I shouldn't remove (or unplug) the MASTER module and just feed that 5V straight into the bus in its place? Obviously I don't want to have both master and external power feeding in. I know people have done both external power via the bus and by feeding something like a 9V Ripcord PSU into the master module.
If I do have a beefy PSU driving a large rack, that should take care of any power problems I might be running into, right? Like, there's not something I'm missing here that would blow up my precious AE?
(I would be losing MIDI and a couple of channels of IO as well, but I think that would be fine for what I tend to do.)
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Post by feijai on Jan 14, 2024 18:12:04 GMT
Isn't there a maximum rated amperage for ribbon cables? The issue is the insulation I think, it's not designed to resist heat. I thought that 3M's cables maxed out at 1.5 amps?
Another approach would be to break the system into multiple ribbon cables that didn't have their power connected, and power them separately.
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pol
Wiki Editors
Posts: 1,278
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Post by pol on Jan 14, 2024 20:43:31 GMT
I am not an electrical expert, the only issue I can see however is that the supply needs to be good quality, an unregulated (or cheap/poor quality regulated) supply will try pumping the 3 amps into your AE regardless of what the modules need. I would suggest a soak test on a small group of modules (expendable?), and if nothing gets too hot then you should be OK!
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Post by solipsistnation on Jan 14, 2024 23:56:20 GMT
Isn't there a maximum rated amperage for ribbon cables? The issue is the insulation I think, it's not designed to resist heat. I thought that 3M's cables maxed out at 1.5 amps?
Another approach would be to break the system into multiple ribbon cables that didn't have their power connected, and power them separately.
Yeah, I’m also trying to figure out if I can split a big rack cleanly and reversibly… I’ll probably end up taking bigger cpu-driven modules and isolating them in a sort of compute rack, and leave the lil filters and analog stuff in the bigger one. |
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Post by solipsistnation on Jan 15, 2024 17:55:51 GMT
Okay, the ribbon cables are 28AWG. That's 1.5A max, yep. That's still about double the max current from a MASTER module, and even with a bunch of chonker modules in there it's hard to get much above that in a 4x20. I'll think about this some more though since I don't want to blow up any modules...
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Post by keurslagerkurt on Jan 15, 2024 18:07:50 GMT
Even cheap power supplies will not try to chunk these amps into your system. The current is only determined by the 'demand' from your modules. If your modules don't demand more current, the PSU won't deliver it (there are some specific 'current regulated' supplies who will try to do this, but these are expensive and for niche cases, all basic PSU's are so called 'voltage controlled' unless marketed otherwise.) So no problem there.
When you split to multiple ribbon cables in parallel right out of the PSU, it should be safe to be honest. As long as it split into roughly the same loads.
Biggest question i see: how regulated is this PSU? Because most modules depend on a steady and clean 5V for reference, eg for 1V/oct etc.
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Post by solipsistnation on Jan 15, 2024 18:19:41 GMT
I don't actually have a PSU in mind yet-- I have a box of old wall warts (so "Not very regulated") and some better PSUs kicking around. I wanted to get some ideas about it before getting too far into it.
Since it's a bus with multiple ribbon cables, each individual row/cable wouldn't have more than roughly 1/4 of the current on it anyway (and even if I stick all the beefy modules in one row, it shouldn't get over a few hundred mA), so the current on a given row wouldn't be too high.
I can probably come up with a decent regulated PSU without too much trouble, anyway. I have access to surplus lab equipment and stuff like that. And a linear PSU would be less noisy than a switcher, right?
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Post by keurslagerkurt on Jan 15, 2024 22:14:42 GMT
Come to think of it: the bus cable uses two wires for both 5V and for GND, so double wires to carry the current. So it should actually be able to do three amps i think?
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Post by feijai on Jan 16, 2024 0:23:09 GMT
Okay, the ribbon cables are 28AWG. That's 1.5A max, yep. That's still about double the max current from a MASTER module, and even with a bunch of chonker modules in there it's hard to get much above that in a 4x20. I'll think about this some more though since I don't want to blow up any modules... Well I have no idea who makes the ribbon cables for Tangible Waves, just that 3M's version can only handle 1.5A. |
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Post by tIB on Jan 19, 2024 6:13:59 GMT
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Post by solipsistnation on Jan 19, 2024 16:42:17 GMT
Ah cool, ok. I thought I'd seen something like it before. Neat. |
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