#garfield Logs

Nov 25 2020

09:21 AM rue_mohr: L = k*t^2 L = inductance, k=core factor, t = turns of wire
09:28 AM rue_mohr: the orig core was 20uH at 25 turns
09:28 AM rue_mohr: k = 0.032
09:28 AM rue_mohr: inductance target was 5000uH
09:28 AM rue_mohr: 5000/0.032 = 156250, square root is 395.28
09:28 AM rue_mohr: hmm, I had 263 turns
09:28 AM rue_mohr: I think
09:47 AM aandrew: rue_mohr: how are you printing the spools? I mean they're cylinders with larger diameter circles on the ends, so they wouldn't print real nice "upright" and would need support in the middle if printed on their side. Did you split them in half or something?
11:26 AM rue_mohr: 3 parts
11:26 AM rue_mohr: one with an end and the tube
11:26 AM rue_mohr: two rings, and a square end
11:26 AM rue_mohr: all glued up
11:26 AM rue_mohr: |---- | | | <<<
11:29 AM rue_mohr: if your interested I can post them
05:02 PM Tom_L: you say that in such a negative way :)
05:03 PM Tom_L: i get it though. i've been dealing all day
07:00 PM aandrew: darn. power came back before Ig ot home
07:00 PM aandrew: unfortunately the firewall ate the USB key it boots from so I gotta figure that out
08:13 PM rue_mohr: hmm
08:13 PM rue_mohr: I think I'm gonna raid the usb keys that hold the music on the jukebox
08:13 PM rue_mohr: some of the songs are startin to play funny
08:33 PM rue_mohr: ok, so, post spool
09:08 PM rue_mohr: heh, thingiverse is broken
09:09 PM Tom_L: what's broke about it?
09:09 PM Tom_L: loads here
09:11 PM rue_mohr: yea, it defaulted my post to someone elses project info
09:11 PM rue_mohr: then only uploded the images
09:11 PM rue_mohr: aandrew, you alive?
09:14 PM rue_mohr: https://www.thingiverse.com/thing:4665730
09:31 PM rue_mohr: and their previews dont work anymore
09:33 PM Tom_L: i can get that zip
09:33 PM Tom_L: and see what it is? what's not working?
09:33 PM rue_mohr: zip?
09:34 PM rue_mohr: the lvdt works
09:34 PM rue_mohr: would be nice to have a cnc lathe to spit out a bunch, whatever
09:47 PM Tom_L: how many do you need?
09:47 PM Tom_L: i thought this was just an experiment
11:18 PM rue_shop1: it kind
11:18 PM rue_shop1: is
11:18 PM rue_shop1: I need about 188 pressure sensors
11:18 PM rue_shop1: for the air muscle robot
11:18 PM rue_shop1: as of yet, I don't have an affordable source
11:18 PM rue_shop1: and no, those ones online aren't cheap enough
11:19 PM rue_shop1: I'm having an issue with the current linearity from my circuit tho
11:19 PM rue_shop1: I need lower impedence inductors
11:20 PM rue_shop1: 188 pressure sensors for $30 is technically over budget
11:37 PM rue_mohr: <rue_shop1> 7.8 ohms 5mH
11:38 PM rue_mohr: but
11:38 PM rue_mohr: 780mV
11:38 PM rue_mohr: I wonder if thats the error I'm seeing
11:39 PM rue_mohr: the output square wave is drooping
11:39 PM rue_mohr: n
11:39 PM rue_mohr: ideally I should have _--_
11:40 PM rue_mohr: I have pretty darn ideal with the op-amp integrator
11:42 PM rue_mohr: I could do better current control on the inductor if it had a secondary I could do voltage control on