#robotics Logs

Jul 20 2018

01:25 AM rue_mohr: ok, hmm, LC osc's sure are clean and stable
01:41 AM Jak_o_Shadows: SpeedEvil, threaded rod is probably the most robust solution
01:50 AM rue_mohr: everyone says it wears and out and just dosn't
01:50 AM rue_mohr: it wears, I never seen a peice worn out
01:50 AM rue_mohr: wow ok
01:51 AM rue_mohr: so, the different between an rf oscillator and an rf reciever, is _one_ inductor
01:52 AM rue_mohr: http://www.circuitdiagramworld.com/uploads/allimg/201411/Articlrx_493253243.gif
01:52 AM rue_mohr: just take out Ft and its an oscillator
02:17 AM mrdata: rue_mohr, 'take out Ft' -- you mean short it? or leave it open
02:17 AM mrdata: i guess short it
02:19 AM mrdata: ?
02:20 AM mrdata: i'm reviewing impedance matching and filters including Q factor and input/output impedance
02:23 AM mrdata: that circuit is a bit strange
02:23 AM mrdata: some discussion of what everything does is warranted
02:25 AM z64555: may be an FM reciever
02:26 AM z64555: the LC tank above the first transister passes the target signal
02:26 AM z64555: and that feeds back into the transister and drives it
02:27 AM z64555: I'm not sure what's limiting the signal from growing too much
02:29 AM rue_mohr: wow
02:30 AM rue_mohr: digging thru old pages in a book that I did when I was a kid, looking for the toy recievers I'd reverse engineered
02:30 AM rue_mohr: found a page on the 74ls373, it looks like THE page
02:30 AM rue_mohr: I STARTED with the 74ls373
02:30 AM rue_mohr: the first logic chip I ever got working
02:31 AM rue_mohr: wow, how I wish it had a date
02:31 AM z64555: put that sucker in a glass case
02:33 AM rue_mohr: has to be mid 80's that one
02:33 AM z64555: hm.
02:34 AM rue_mohr: the stuff is advanced enough it makes me wonder if I'v really come far since
02:35 AM z64555: You've probably have come far, but in different directions
02:35 AM rue_mohr: a design for a 400W battery
02:35 AM rue_mohr: oof
02:38 AM rue_mohr: ok, yea the gates are backwards in that one, I had some challanges understanding what was in and out for a while
02:45 AM rue_mohr: haha a servo witha 4017 controler
02:47 AM rue_mohr: I was designing a lot of cpu-less 4 bit robot controllers
02:47 AM rue_mohr: that used tape storage
03:01 AM rue_mohr: heh
03:01 AM rue_mohr: in this one, a 7490 runs a relay, that latches an SCR that operates a BJT
03:01 AM rue_mohr: god I wish someone had been able to help me
03:06 AM rue_mohr: all that said, I can understand these circuits I was reverse engineering now
03:07 AM rue_mohr: I'm looking at the vert deflector circuit of a tv, totempole driver with a neat feedback arrangement
03:21 AM rue_bed: I was reversing out a lot of pcbs
03:35 AM rue_bed: I need a slow version of the 3N501
11:39 AM z64555: tape storage on a servo? how big of a servo
09:48 PM rue_shop4: no
09:48 PM rue_shop4: different circuits