#garfield Logs

Jun 26 2023

12:24 AM rue_mohr: - replace tires on lawn tractor
07:22 AM rue_mohr: morning
07:48 AM polprog: morning
08:05 AM rue_mohr: messed up weekend
08:05 AM rue_mohr: they had an oops and I needed to be put on-call for maintenance
08:06 AM rue_mohr: two different callouts on the weekend to fix things
08:14 AM polprog: :/ shame
08:14 AM polprog: do you work on every weekday or can you take some rest now?
08:15 AM rue_mohr: normal workweek ahead
08:18 AM polprog: eh
08:20 AM aandrew: it always sucks when you have your own plans laid out and then reality comes along and slaps you across the face with its own plans
08:21 AM rue_mohr: I wanted to take the trike into town this weekend
08:21 AM aandrew: when you're married this happens practically every single day, and you get a healthy dose of "why do you never get anything done?" :-)
08:22 AM aandrew: rue_mohr: if I remember correctly your road is a bit of a long blind turn, I'd be pretty worried about getting run over. Do you have a couple of those long fiberglass poles with orange flags on them to try to increase visibility?
08:22 AM rue_mohr: the side that goes to gibsons is ok, the side that goes to sechelt is a deathtrap in waiting
08:26 AM aandrew: personally that mecha at the driveway would scare the shit out of most drivers if it had a skin
08:26 AM aandrew: that'd slow down the vechicles. :-)
08:26 AM rue_mohr: I dont think anyone sees it
08:26 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1280860.jpg
08:26 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1280861.jpg
08:26 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1280862.jpg
08:26 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1280863.jpg
08:26 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1280865.jpg
08:26 AM aandrew: well like I said it needs a skin
08:26 AM rue_mohr: project case worked out nice :)
08:26 AM aandrew: yeah it really did
08:27 AM aandrew: it always amazes me how GOOD basic FDM 3D printing can be. it's really a revolutionary technology
08:27 AM rue_mohr: I worked hard to make a keepout zone on the pcb so I could do that with the lugs
08:32 AM rue_mohr: did you catch my circuit for pulling in a 50A contactor?
08:32 AM rue_mohr: 48V is apparently enough, and it holds fine all the way down to like 2v
08:32 AM rue_mohr: (dc)
08:32 AM rue_mohr: despite the 240VAC coil
08:32 AM aandrew: no - did you play a trick where you use an cap to briefly draw more current to help seal in the contactor?
08:34 AM rue_mohr: its a cap...
08:34 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1280854.jpg
08:35 AM rue_mohr: not sure I had to go to that much trouble tho
08:35 AM rue_mohr: little voice in the back of my head says it should be simpler
08:35 AM aandrew: interesting; voltage doubler? I am only about three sips into my coffee and my baby meth hasn't kicked in yet
08:35 AM rue_mohr: during the off time it charges the cap
08:36 AM rue_mohr: then the cap boosts, so yea
08:36 AM rue_mohr: mm yea the top resistor could go away...
08:37 AM rue_mohr: and if the input switch was spdt it could switch to ground to charge it
08:37 AM aandrew: depending on how much oomph you need you can do what we did for the gate drivers: R || C, it would give a nice initial "whack" to the SCR gate and then the cap would charge and the resistor would limit the holding current for the remaining fire time
08:38 AM aandrew: but for a big contactor I doubt that would be sufficient. For our big contactors we had an SCR that we'd use, couple cycles of full voltage, then something like 60 or 75 degrees to hold it in
08:38 AM rue_mohr: 48V from 1000uF was pulling it in reliably
08:39 AM aandrew: no I meant the R || C I mentioned for firing SCR gates
08:39 AM aandrew: 1000u at 24V is a decent amount of energy
08:40 AM rue_mohr: and that bumps it up to 48V
08:40 AM aandrew: yep. voltage doubler circuitry always takes me a few tries to grok
08:40 AM rue_mohr: heh
08:40 AM rue_mohr: that method came up on a low voltage led flasher
08:41 AM rue_mohr: related to an LM3909 conversation
10:26 PM rue_mohr: so I got some replacement burners for the gas stove
10:26 PM rue_mohr: my cross-over wasnt' quite right
10:26 PM rue_mohr: so I had to modify a lot of things
10:26 PM rue_mohr: here is hoping it all works out
10:37 PM Tom_L: you can put faster ram in a pc right? it just may not use it's full potential
10:43 PM rue_mohr: well
10:43 PM rue_mohr: it'll run the ram slow if the clocks dont match up nice
10:48 PM Tom_L: DDR4 3200 but the board supports 2400/2133
11:09 PM rue_mohr: yea, the wait states are integer
11:10 PM rue_mohr: so but if the ram is faster I think you should be ok
11:10 PM rue_mohr: ARG, ma trimmed some grass that keeps the mower off an embankment and now its just fixated on driving over it