#garfield Logs
May 02 2020
#garfield Calendar
12:06 AM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1150903.jpg
12:12 AM rue_mohr: the motor driver I been working on
02:44 AM polprog: i didnt know you have a hardcopy of the yellow Graf book rue_mohr, cool
02:44 AM rue_mohr: I have another hard copy coming
02:44 AM rue_mohr: I'v already started making notes on things
02:44 AM rue_mohr: in it, like missing part numbers and value corrections
02:45 AM polprog: wish i had space for these
02:45 AM polprog: shower, breakfast time
02:48 AM rue_shop1: I worry that I see you go to bed AND wake up on most nights
03:50 AM polprog: heh, its ok
03:51 AM polprog: for some reason i woke up today pretty fresh at 5 in the morning, decided its too early and went back to sleep, to wake up tired and sweaty at 9..
03:52 AM polprog: should have closed the curtains
12:34 PM rue_mohr: ok, I need to finish the motor driver before I get distracted
12:34 PM rue_mohr: then I should finish the filter profiler
12:35 PM rue_mohr: I might do a mod to the profiler, to do votlage->freq readings
12:35 PM rue_mohr: for things like VCOs
12:35 PM Tom_L: yard mowed
12:35 PM Tom_L: showered
12:35 PM Tom_L: time for lunch
12:36 PM rue_mohr: that said, I supposed making it able to do freq->voltage converter measurements is good too
12:36 PM rue_mohr: Tom_L, its raining
12:36 PM rue_mohr: fillin up the greenhouse jug I recon
12:36 PM Tom_L: taters sprouting yet?
12:37 PM rue_mohr: oh yea
12:37 PM rue_mohr: I need to make deer guards
12:38 PM Tom_L: i had to do that with wabbits
12:38 PM Tom_L: and crows
12:38 PM rue_mohr: hmm
12:38 PM rue_mohr: lots of rabbits there?
12:38 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/house/house.jpg
12:39 PM Tom_L: look in the middle and you can see some 1/2" wire
12:39 PM Tom_L: covers
12:39 PM rue_mohr: pre-patio?
12:39 PM Tom_L: thats a very old pic
12:39 PM Tom_L: see the kid toys? they're 20 now :)
12:39 PM rue_mohr: before the basement mod?
12:39 PM Tom_L: no
12:39 PM Tom_L: after
12:40 PM Tom_L: i never did add on the corner of the garage
12:40 PM Tom_L: that was the plan
12:40 PM rue_mohr: I'm thinking the patio is to the left of that image
12:40 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/house/yard1.jpg
12:40 PM Tom_L: before i covered it
12:41 PM Tom_L: where the AC is is where the dozer went under the house
12:41 PM rue_mohr: ah ok
12:41 PM Tom_L: tree by the house is 10' circumference now
12:42 PM rue_mohr: fast grower
12:42 PM Tom_L: not that much
12:43 PM Tom_L: i should have measured it when i moved in
12:44 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/house/1.jpg
12:46 PM rue_mohr: need to sketch up a 8'x12' shed
12:47 PM rue_mohr: see if I can make an order package
12:49 PM Tom_L: 12 sheets of plywood
12:49 PM Tom_L: more for the roof
12:50 PM rue_mohr: ?
12:50 PM Tom_L: 12' is 3 sheets
12:50 PM Tom_L: 8' is 2
12:50 PM rue_mohr: ?
12:50 PM rue_mohr: our sheets are 8'x4' here
12:50 PM Tom_L: 8 x 12 shed
12:50 PM Tom_L: so are ours
12:51 PM Tom_L: 12/4 is 3
12:51 PM rue_mohr: 3 sheets floor
12:51 PM rue_mohr: |||
12:51 PM Tom_L: oh you want a floor too?
12:51 PM Tom_L: no slab
12:51 PM rue_mohr: no I want to sell it
12:51 PM rue_mohr: so I can build more
12:51 PM rue_mohr: so that I can not be first-build for a temp place to stay while I build a new house
12:54 PM rue_mohr: I wonder dare I do 24" studs?
12:55 PM rue_mohr: a small building like that, its technically ok
12:56 PM rue_mohr: looks like floor can be 2x6 @ 16"
12:56 PM rue_mohr: (8' span)
12:58 PM rue_mohr: when I built that fire shed, I reduced the wall height to make it not crazy tall, wondering about that too
01:01 PM rue_mohr: motor driver
01:01 PM rue_mohr: need to finish the motor driver
01:01 PM polprog: not sure whether to work on the lab report or try making a crystal oscillator
01:05 PM polprog: brought a UHF+VHF antenna from the summer house, it was laying behind the shed
01:05 PM polprog: half wave folded diploe + 4 pairs of V-shaped reflectors
01:06 PM polprog: might do some SDR experiments
01:06 PM rue_shop1: hmm
01:06 PM rue_shop1: the lab report is about graphing?
01:06 PM polprog: i have some trunking system (airport ground control and some couriers) beacons around
01:06 PM polprog: nah, the lab report is about measureing an unknown resistance
01:06 PM polprog: or rather about reading digital and analog meters
01:07 PM rue_shop1: hmm, hard to twist the freq variation of a crystal osc into that
01:07 PM polprog: no, not related to the antenna
01:07 PM rue_shop1: over say, a 1V supply voltage delta
01:07 PM rue_shop1: tho, you could plot the impedence of the crystal as a fn of freq
01:08 PM rue_shop1: that would be close to your lab
01:08 PM polprog: i have a couple of crystals that id be happy to use in a single transistor oscillator
01:08 PM polprog: not sure if something like the phase shift osc, or one of your C-L-C feedback osc would work if i swapped the L with the crystal
01:09 PM rue_shop1: did you see the ones posted to my on twitter there?
01:10 PM polprog: yeah
01:18 PM polprog: i was thinking about a regular phase shift osc
01:18 PM polprog: https://pbs.twimg.com/media/EWK1FfeUwAASBrJ?format=jpg&name=large
01:18 PM polprog: disclaimer - i have no idea how bare crystals work
01:53 PM polprog: ok, report sent, crystal time
01:56 PM polprog: i found a 2N2222, datecode 9715
02:00 PM rue_shop1: 2222 is fine
02:00 PM rue_shop1: 300Mhz, gain ~300 vce~30
02:01 PM rue_shop1: ~500mA
02:01 PM rue_shop1: which is the same ratings as like 1/3 of the transistors out there
02:19 PM polprog: hmm, doesnt wanna resonate
02:20 PM polprog: trying to build a pierce osc
02:39 PM ShopMoon: Got my driver to Blue Screen Of DEATH :) big smiles
02:55 PM rue_mohr: ah good show
02:55 PM rue_mohr: polprog, show circuit I might be able to help
03:18 PM polprog: just realized "12.000" on the xtal may mean mhz
03:18 PM polprog: ive managed to build a phase lag opamp osc.
03:18 PM polprog: im trying to build https://www.tutorialspoint.com/sinusoidal_oscillators/sinusoidal_crystal_oscillators.htm
03:18 PM polprog: https://www.tutorialspoint.com/sinusoidal_oscillators/images/transistor_pierce.jpg
03:22 PM polprog: so far it just does not oscillate..
03:22 PM polprog: idk what is RFC for
03:29 PM polprog: heres my circuit
03:29 PM polprog: https://ibb.co/F40CmDz
03:34 PM rue_shop3: hmm, what gear ratio turns 300 degrees into 360
03:35 PM rue_shop3: ah yo ugot it then!
03:35 PM polprog: but it doesnt work..
03:35 PM rue_shop3: oh, you didnt?
03:35 PM polprog: i mean
03:35 PM polprog: the one that works was the opamp RC one
03:35 PM polprog: the xtal one doesnt work
03:35 PM rue_shop3: there are no values on these
03:35 PM rue_shop3: ah
03:35 PM rue_shop3: ok!
03:36 PM rue_shop3: still here?
03:36 PM polprog: yeah
03:36 PM polprog: got it ready on breadboard
03:36 PM rue_shop3: take the emitter and go right to ground
03:36 PM rue_shop3: whats vcc?
03:36 PM polprog: 5, but can be anything
03:36 PM rue_shop3: ok, change the collector resistor to 1k
03:36 PM rue_shop3: remove the votlage divider
03:37 PM rue_shop3: have a resistor about 100k -> 470k?
03:37 PM rue_shop3: variable is good
03:37 PM polprog: yeah, in a kit
03:37 PM polprog: i can do 100k pot + R
03:37 PM rue_shop3: ok,
03:37 PM rue_shop3: note: that 32khz resonator you have is REALLY hard to get going
03:37 PM rue_shop3: whats the resistor you got?
03:38 PM polprog: let me pick one
03:38 PM polprog: i understand we wanna make this common emitter amp have as much gain as possible?
03:38 PM rue_shop3: yep
03:39 PM rue_shop3: lets see, I'll be a bit hit-and miss
03:39 PM polprog: 680k good?
03:39 PM rue_shop3: sure, variable, right?
03:40 PM polprog: that would be 100k variabke + 680k in series
03:40 PM polprog: so 680k - 780k
03:40 PM polprog: we can go lower..
03:40 PM rue_shop3: hmm, bit high
03:40 PM rue_shop3: 470k is usually an upper limit
03:40 PM polprog: 87k + 100k
03:40 PM rue_shop3: sure, lets try it
03:41 PM polprog: hmm, 154k
03:41 PM rue_shop3: ok, take out the resonator and the cap for a bit
03:41 PM polprog: thats 200k in paralell with that 68k and the pot in series
03:41 PM rue_shop3: put a volt meter across the CE of the transitor
03:41 PM rue_shop3: our goal is 1.5->2V
03:41 PM rue_shop3: put the variable resistor from the base to the collector of the transitor
03:42 PM rue_shop3: (self biased)
03:42 PM rue_shop3: check the voltage
03:43 PM rue_shop3: do you have a normal crystal to try with? 1->20Mhz?
03:43 PM polprog: 12M
03:44 PM rue_shop3: k, is it larger than that resonator?
03:44 PM polprog: pot goes between B and GND, where does the 154k resistor go?
03:44 PM polprog: its a bigger can, its about 1x1cm
03:44 PM rue_shop3: ah, we want to put ~200k from the collector to the base
03:45 PM rue_shop3: that creates a self-biased amp
03:45 PM rue_shop3: the collector will come down from 5V, we want a "bit low"
03:45 PM rue_shop3: normally you would bias an amp to 2.5V if vcc is 5V, but oscillators are funny
03:45 PM rue_shop3: they generally need to be biased a bit low
03:45 PM polprog: ok, got 200k between the base and collector
03:46 PM polprog: now the pot?
03:46 PM rue_shop3: ah, pot in series
03:46 PM rue_shop3: heh
03:46 PM polprog: with the 200k?
03:46 PM rue_shop3: we want to adjust it to find the bias point
03:46 PM rue_shop3: sure
03:46 PM rue_shop3: but what CE voltage do you get with the 200k?
03:46 PM polprog: ok
03:47 PM polprog: 3.21
03:47 PM rue_shop3: ok too high, we want a lower resistance
03:47 PM rue_shop3: so maybe just stick the pot in there
03:47 PM rue_shop3: try to dial it so that the CE voltage is about 1.5->2V
03:47 PM rue_shop3: less resistance will lower the CE voltage
03:48 PM polprog: ok, im able to go between 2.5 to 0.6, more than enough
03:48 PM polprog: got it at 1.86
03:48 PM rue_shop3: ok, set it to 2V
03:49 PM rue_shop3: check what the resistor is set to, see if you have a static resistor about that value
03:49 PM rue_shop3: (see why I want to build a decade box?)
03:49 PM polprog: yeah
03:49 PM polprog: i need one too
03:49 PM rue_shop3: I'm playing with an analog idea now too
03:49 PM rue_shop3: whats the magic value?
03:50 PM polprog: 59k
03:50 PM rue_shop3: ok, got a 56k static?
03:50 PM polprog: i think so.. let me get
03:50 PM rue_shop3: :) and is that close enough
03:50 PM rue_shop3: sometimes the values are really touchy
03:52 PM rue_shop3: ooo this thing would be huge
03:52 PM polprog: not in the kit.. ill check the junk
03:52 PM polprog: 68 is closest
03:52 PM polprog: 68k
03:52 PM polprog: maybe your ohm prog can pick a second one
03:53 PM polprog: i need to install ohm ;)
03:53 PM rue_shop3: sure, try it, see what the CE goes to
03:53 PM polprog: i have 51k
03:53 PM rue_shop3: ohm just does ohms law :)
03:53 PM rue_shop3: try it!
03:53 PM rue_shop3: whats the CE? still close?
03:54 PM polprog: 68k => 2.08,
03:54 PM polprog: 51k is good.. 1.83
03:54 PM rue_shop3: ok
03:55 PM rue_shop3: so, what do you have for capacitors in the 100pf-1000pf range?
03:56 PM polprog: 100p. 470p
03:56 PM polprog: etc
03:57 PM rue_shop3: ah ok
03:57 PM rue_shop3: so, with the 12Mhz crystal
03:57 PM rue_shop3: hmm
03:57 PM rue_shop3: this is wierd give it a try
03:58 PM rue_shop3: put a 1000pf across the transistor CE
03:58 PM rue_shop3: say when...
03:59 PM rue_shop3: I"m adjusting another oscillator I did once
04:01 PM polprog: ugh
04:01 PM rue_shop3: ?
04:01 PM polprog: i have the ceramic caps mislabeled
04:01 PM polprog: "470pf" read 4n7
04:01 PM rue_shop3: oops
04:01 PM rue_shop3: 4n7 being 4700pf
04:01 PM polprog: so 1000p is gonna be a 103
04:01 PM polprog: 102*
04:02 PM rue_shop3: 102
04:02 PM rue_shop3: 104 is 0.1uF
04:02 PM rue_shop3: 103 is 0.01uF
04:02 PM rue_shop3: 103 is 0.01uF aka 10nF
04:02 PM rue_shop3: 102 is 1nF
04:02 PM polprog: ok, got one
04:02 PM polprog: measures 0.16nF but idk how accurate the brymen is
04:03 PM rue_shop3: ok, goes across the CE of the transistor
04:03 PM polprog: wtf
04:03 PM rue_shop3: I know
04:03 PM rue_shop3: rf is evil
04:03 PM polprog: i cant make out the last digit on the cap
04:03 PM rue_shop3: next we want two caps, preferably about 100pf and 330pf
04:04 PM polprog: must be 102, 103 is another bag
04:04 PM polprog: whatever, lets try it
04:04 PM rue_shop3: yup
04:04 PM rue_shop3: so, "101" should be 100pF
04:05 PM polprog: ok, its in
04:05 PM rue_shop3: ?
04:05 PM polprog: sec, need to put some stuff back in off the bench
04:05 PM polprog: ive put the cap across CE
04:06 PM rue_shop3: we want a 330pf across the BE of the transistor
04:06 PM rue_shop3: say when you got that
04:07 PM rue_shop3: so, strange enough, MOST of my crystal osc's use a non-inverting amp...
04:07 PM polprog: 332..
04:07 PM rue_shop3: no 331
04:07 PM rue_shop3: 33*10^1
04:08 PM polprog: ah
04:09 PM rue_shop3: oh no, my gear library...
04:09 PM rue_shop3: (I reinstalled this machine, think I forgot some things)
04:10 PM polprog: only got 471
04:10 PM rue_shop3: ok, go for it
04:11 PM rue_shop3: across BE
04:11 PM rue_shop3: next we want ~100pf
04:11 PM polprog: ah, no got 331
04:11 PM rue_shop3: ok
04:12 PM rue_shop3: one of the things I learned too late, was that values aren't often super critical, if a circuit it robust, it'll just work
04:12 PM rue_shop3: got a 100pf?
04:13 PM polprog: think so
04:13 PM polprog: 102
04:13 PM rue_shop3: 101
04:13 PM rue_shop3: :)
04:13 PM rue_shop3: your doing a good job at moofing your multiplier
04:14 PM polprog: ugh
04:15 PM aandrew: Any love for old PLCC DSPs? I just discovered a ton of socketed ADSP2101 and I think 2110s
04:15 PM rue_shop3: heh, too little time
04:15 PM rue_shop3: msp420?
04:15 PM aandrew: rue_shop3: too true re: component values
04:16 PM polprog: i dont think i have these
04:16 PM polprog: i have 151 cosest
04:16 PM rue_shop3: sure!
04:16 PM rue_shop3: ok, so, were going to put it in series with the crystal
04:16 PM rue_shop3: the series set, goes between the .. collector and base of the transistor
04:17 PM rue_shop3: then see if its oscillating!
04:17 PM rue_shop3: :D
04:18 PM polprog: it is
04:18 PM rue_shop3: !!!!!
04:18 PM rue_shop3: is it running at about the right freq????
04:19 PM polprog: 11.997Mhz
04:19 PM rue_shop3: coool!
04:19 PM polprog: yess!
04:19 PM rue_shop3: so, the output wave
04:19 PM rue_shop3: is it all mis-shapen?
04:19 PM rue_shop3: like, its not a good sine wave?
04:19 PM polprog: its sin-ish
04:19 PM polprog: let me check the fft
04:19 PM rue_shop3: hah
04:19 PM rue_shop3: play with the bias resistor first
04:20 PM aandrew: Spent all afternoon cleaning out some of the garage. Sadly my two logic analyzers (tek 1281 and something else I don’t remember) are at the curb
04:20 PM rue_shop3: then play with the 3 capacitor values a bit
04:20 PM polprog: bias doesnt do much
04:20 PM rue_shop3: polprog, you should be able to get it a good sine wave, but it might be at the cost of signal strength
04:21 PM polprog: ive got first and second harmonic at -20dbV
04:22 PM rue_shop3: :)
04:22 PM polprog: gimme a sec to draw it
04:23 PM rue_shop3: I like self bias, over power supply variations, its the most stable
04:23 PM polprog: ah, wait, the pot was disconnected
04:23 PM rue_shop3: at a glance, the bias voltage you has was way too high
04:23 PM rue_shop3: heh
04:25 PM rue_shop3: once you have something that works, play with the values, and see if you can improve its operation
04:25 PM rue_shop3: if you can get a good sine wave, with good amplitude, it can be turned into a nice square wave digital
04:26 PM rue_shop3: otherwise the duty is all strange
04:28 PM polprog: heh, got a better amplitude removing the 100pf actoss CE
04:28 PM polprog: across
04:28 PM rue_shop3: huh
04:29 PM rue_shop3: ok, I suppose that makes sense
04:29 PM rue_shop3: dont need DC removal
04:29 PM polprog: not got 25dBV between primary and secondary harmonic
04:29 PM rue_shop3: also, every so often, make sure the circuit can still start
04:29 PM polprog: but the 3rd harmonic is just a tad smaller than the 45h and the 5th
04:29 PM rue_shop3: sometimes a mod improves a circuit but removes its ability to start up
04:30 PM aandrew: mosquito magnet set up for the season, snowblower run dry and put away, lawn mowers brought out... shitloads of garbage ofr monday
04:31 PM aandrew: also got youngest son to almost ride a bike by himself
04:32 PM rue_shop3: :)
04:33 PM aandrew: the way the boys approach problem solving is interesting
04:34 PM rue_shop3: where are the curves in these gears...
04:34 PM rue_shop3: drat
04:34 PM rue_shop3: aandrew, listening...
04:34 PM aandrew: the older one will get frustrated and reject help and be sullen, but come back to it independently and fight on it on his own, like me
04:35 PM aandrew: the younger one will keep at it as long as you're helping and encouraging him
04:35 PM rue_shop3: hmm
04:35 PM aandrew: but if he doesn't see you interested he's much less likely to work on it himself
04:35 PM polprog: lol, it works without any caps..
04:35 PM polprog: it was just the bias
04:36 PM polprog: ;)
04:36 PM rue_shop3: what?
04:36 PM aandrew: polprog: reminds me of my first DAC design with the DAC0800 on the parallel port
04:36 PM polprog: works better with 330p between BE
04:36 PM rue_shop3: on mine, as soon as I removed the CE cap, it stopped
04:36 PM aandrew: it sounded best when NONE of the data lines were connected
04:36 PM polprog: aandrew: oh, do tell me
04:36 PM polprog: maybe i have a better breadboard :P
04:36 PM aandrew: IIRC DAC0800 is a current output which is something I didn't understand back then
04:36 PM rue_shop3: did you hook up the ground plane on yours?
04:37 PM aandrew: ... breadboards have ground planes?
04:37 PM rue_shop3: heh
04:37 PM polprog: what??
04:37 PM rue_shop3: they stickyback
04:37 PM polprog: oh
04:37 PM rue_shop3: they used to come with a sheet of aluminum
04:37 PM rue_shop3: you stick it to the back and ground it
04:37 PM polprog: mine come with foam
04:37 PM rue_shop3: yea, peel-off sticky
04:37 PM rue_shop3: so you can stick on a ground plane
04:37 PM polprog: ok, i got 6V amplitude from Vcc = 5V
04:37 PM aandrew: yeah I guess you could do that, never thought to do that
04:38 PM polprog: fReEe EnErGy
04:38 PM rue_shop3: hah, yea, I hate rf
04:38 PM rue_shop3: well they dont come with the sheet of aluminum anymore
04:38 PM polprog: funny, the 40MHz xtal runs at 13mhz
04:38 PM rue_shop3: bad mode
04:38 PM polprog: i guess i could take the aluminum from the chocolate bar on the other desk and use that
04:38 PM rue_shop3: sure...
04:39 PM aandrew: I felt really bad tearing that ameritech T1 test fixture apart, but every now and again I get into what i call "cleaning mode" and I have the strength to either strip down or throw out the things I can't bear to discard
04:39 PM polprog: 14.756MHz xtal runs at 14.744MHz
04:39 PM aandrew: polprog: perhaps your caps are pulling it off center
04:39 PM polprog: i only have a 330p cap between B and E
04:40 PM rue_shop3: polprog, yea, the circuit is t bit TOO crude
04:40 PM rue_shop3: if you load a crystal "wrong" you push its freq off
04:40 PM rue_shop3: thats why clock circuits have trim caps on one side of the crystal
04:41 PM polprog: yeah
04:41 PM polprog: ok, it can do 25M pretty okay
04:42 PM aandrew: actually the last contract i had was all about IEEE1588 (precision time protocol) - that kind of gave me this bug about frequency accuracy
04:42 PM rue_shop3: yea, your way over the breadboard rating :)
04:43 PM aandrew: I have a GPSDO now that I will use as a master 10MHz reference everywhere in the lab
04:43 PM aandrew: the time-nuts mailing list is filled with people who are FAR more seriously afflicted with this particular bug than I am :-)
04:43 PM rue_shop3: so far, I dont care much
04:43 PM rue_shop3: the tek is horrid tho
04:43 PM aandrew: but I also learned about the TDC7200 from that list; it's a super cheap SPI-connected ring oscillator used for timing measurments (like a stopwatch) -- picosecond resolution
04:44 PM rue_shop3: its freq measurement is really only a ballpark
04:44 PM rue_shop3: cool
04:44 PM aandrew: these are all guys with Rb oscillators and multiple GPSDOs and talking about Allen deviation scores
04:45 PM polprog: rue_shop3: are you using the freq function or the counter function?
04:45 PM polprog: on my agilent the latter one is more accurate (hw counter), the freq takes display data
04:45 PM aandrew: there is *so much* to learn about everything in the world, so many interesting and tiny little facets of various things in all areas of the universe... I don't know how people can ever claim to be bored
04:45 PM rue_shop3: the measure -> freq
04:45 PM rue_shop3: I have a good counter tho, so its ok
04:46 PM polprog: does the tek have a builting counter?
04:46 PM polprog: check it..
04:46 PM rue_shop3: a long time ago I bought an LDC-822 counter off ebay
04:46 PM rue_shop3: I been happy with it
04:46 PM rue_shop3: polprog, in the "measure" menu for channels, you can do freq
04:46 PM polprog: LDC-822, is it that VFD leader counter that sits on the tek?
04:46 PM rue_shop3: yea
04:47 PM polprog: heh, disappoiting then :D
04:47 PM * polprog pats his agilent
04:47 PM aandrew: rue_shop3: checkout the TAPR TICC; it's a board that glomps on to an arduino and gives you something like 62ps resolution on timing... with an arduino
04:47 PM rue_shop3: I beleive the leader to be accurate
04:47 PM rue_shop3: maybe, so far I'm ok
04:47 PM polprog: i have a PFL-23 counter
04:47 PM polprog: its so-so
04:48 PM polprog: sometimes the display freezes (i think the nixie drivers give up due to a dirty supply)
04:48 PM rue_shop3: heh
04:48 PM polprog: its RC-clocked, 10MHz base so no crazy accuracy there
04:48 PM polprog: maybe i could mod it to run off a 10MHz crystal :D
04:49 PM rue_shop3: heh, aandrew $230!!
04:49 PM rue_shop3: yea, I think I got mine for like $50?
04:49 PM aandrew: rue_shop3: yeah it's way overpriced but it's totally open source
04:49 PM rue_shop3: :)
04:50 PM rue_shop3: its 3pm, I should get something to eat today
04:50 PM aandrew: the well
04:50 PM aandrew: it's not actually overpriced
04:50 PM aandrew: dude's design time and the idea itself are worth something
04:50 PM aandrew: but like you, I'd rather spend a week of my time and build my own, which is definitely not cheaper than $250 :-)
04:50 PM aandrew: but it's the principle of the matter
04:52 PM polprog: https://www.youtube.com/watch?v=pA2dQja69fA
04:53 PM polprog: that leader looks very nice inside
04:53 PM polprog: not sure if i want a DSLR or a freq counter or a freq gen on my bday
04:53 PM rue_mohr: aandrew, indeed, its way over what I need :)
04:53 PM polprog: DSLR is the cheapest option...
04:54 PM aandrew: rue_mohr: I get the impression that when you're bitten by the time bug "what you need" is irrelavent. it's all about just how accurate you can get. :-)
04:54 PM aandrew: how many zeroes after "10." in the frequency counter
04:55 PM rue_mohr: well
04:55 PM rue_mohr: that tek scope was an eye opener
04:55 PM rue_mohr: I found myself zoomed all the way in a few times
04:55 PM rue_mohr: its meaningless to be zoomed in that far
04:56 PM aandrew: :-)
04:56 PM rue_mohr: its super neat to be able to really see 20Mhz signals
04:56 PM aandrew: most times "good enough" is a matter of 25%
04:56 PM rue_mohr: much over 500khz and I'v got lots of other stuff coming into play
04:57 PM aandrew: man, I gotta teach the squirrels to dig up the fucking weeds in my flower beds instead of the walnuts they buried
04:58 PM rue_mohr: assosciative
04:58 PM rue_mohr: put a walnut under weeds for a while
04:59 PM polprog: hmm, works okay with a 100k bias
04:59 PM rue_mohr: :) robust circuits
04:59 PM zhanx: ok robot body is done
05:00 PM rue_mohr: "I CAN REDUCE THIS TO JUST ONE TRANSISTOR!!! GIVE ME TIME!!!"
05:00 PM aandrew: rue_mohr: I think you're trying to have me committed
05:00 PM aandrew: "what the fuck is he doing, burying walnuts under the weeds all day"
05:00 PM polprog: rue_shop3: it works fine with both 2n2222 and bc547, 100k and 330pf
05:00 PM polprog: :P
05:00 PM rue_mohr: they like peanuts eh?
05:00 PM zhanx: need to remove the case off the battery pack to reduce some weight
05:00 PM rue_mohr: and z sets himself on fire
05:01 PM zhanx: and just like that AI became deadly
05:02 PM rue_mohr: OMG I HAD TO REBOOT THE TEAPOT
05:02 PM rue_mohr: will it work now???
05:03 PM Tom_L: boston tea party all over again
05:03 PM aandrew: yeah they do
05:04 PM aandrew: back about 20 years ago my dad would spend all of his time live-trapping squirrels and driving them to a park about 10km away. day after day after day,s ometimes twice or thrice a day
05:04 PM rue_mohr: uh ho, I dont think its the arduino that failed
05:04 PM aandrew: his neighbour would just shoot them with a bb gun
05:05 PM aandrew: when dad first had the idea of live trapping them he had a problem where the squirrels would like to come early in the morning but if he left the trap out overnight hte racoons would get stuck and haul the trap into the bush
05:05 PM aandrew: so he electrified the trap
05:05 PM aandrew: one prong in the ground near the trap, the other aligator-clipped to some chicken wire stapled to a few 2x4s that the trap sat on
05:05 PM zhanx: ok removing the case saved me 30 grams of weight
05:06 PM aandrew: then used a simple timer from canadian tire to turn off the electricity at 5am
05:06 PM aandrew: god how much time and energy he wasted on that venture. he's still a little weird, but he's my dad
05:07 PM aandrew: this is also the guy who threatened to disown both my brother and I if we didn't go to university. he never went but wanted better for us and that was how he tried to motivate us
05:07 PM aandrew: funny thing is both my brother and I are doing quite well but neither of us ever went to university or college
05:07 PM aandrew: his heart was in the right place
05:08 PM zhanx: 6700 mha battery pack might have been overkill but it was 5 bucks
05:08 PM aandrew: zhanx: got some pics of the bot?
05:08 PM aandrew: need to live vicariously through you guys :-)
05:08 PM Tom_L: you got to push the ball to see if it will roll where you want it to
05:08 PM zhanx: yea, let me finish making dinner and I will get some better ones
05:09 PM aandrew: when cleaning the garage I found some of hte MiP prototypes
05:09 PM aandrew: (https://wowwee.com/mip/)
05:09 PM aandrew: I wrote the bootloader for that thing
05:09 PM rue_mohr: :)
05:10 PM aandrew: got a nice trip to hong kong out of that contract too, wowwee is a company based in montreal
05:10 PM rue_mohr: neat
05:10 PM rue_mohr: small!
05:10 PM aandrew: yeah it's tiny, about the size of a coke can
05:10 PM aandrew: well maybe 1.5 coke cans tall
05:11 PM aandrew: https://wowwee.com/snappets/ did the hw/fw for those too, whawt a dumb little idea
05:11 PM aandrew: it bugs me that some people just "hit" on the right ideas and make crazy money from them
05:11 PM rue_mohr: I'm gonna hve to end up repairing the tea machine
05:12 PM aandrew: those stupid little cameras took crappy 640x480 pictures and took a good 30s to transfer them over BLE
05:12 PM rue_mohr: I bet the goofy zener regulated power supply is borked
05:12 PM aandrew: tea machine?
05:12 PM rue_mohr: aandrew, lots of great stuff comes out at the wrong time
05:13 PM rue_mohr: yea, I put an esp32 in the coffeemaker I use to perkilate tea
05:13 PM rue_mohr: turn it on via its webpage for 1 of given time periods
05:13 PM rue_mohr: the idea is to have a schedule in there
05:13 PM rue_mohr: that I can add multiple entries to
05:14 PM rue_mohr: as the defacto coffepot only has 1 on-time programming
05:14 PM aandrew: ahh
05:14 PM aandrew: so basically a smarter/iot timer for the heater and pump bits
05:15 PM rue_mohr: the controller just does a relay
05:15 PM aandrew: speaking of percolating, I've got a new interest in distilling alcohol
05:15 PM rue_mohr: the normal hardware takes care of the rest
05:15 PM aandrew: been reading up on it a bit, I think I might want to try making my own palinca (romanian moonshine)
05:15 PM rue_mohr: 80%?
05:16 PM aandrew: seems really, really straightforward process to make alcohol, it's all about temp control
05:16 PM aandrew: rue_mohr: no idea, but it evaporates off your tongue
05:16 PM aandrew: there's good palinca and bad palinca too though... the bad stuff I'd rather use to start my lawnmower
05:16 PM aandrew: the good stuff is so damn smooth though, it's amazing
05:17 PM aandrew: funnily enough, the alcohol has almost zero to do with good/bad moonshine
05:17 PM rue_mohr: dont get it wrong and blind youself
05:17 PM aandrew: any idiot can make 160 proof
05:17 PM aandrew: rue_mohr: that's also actually very hard to do -- methanol and the heads burn off quite a bit "earlier" than ethanol
05:17 PM rue_mohr: ok, so, I was going to make a mechanical resistor box
05:18 PM aandrew: almost all serious poisonings occur because people are trying to purify denatured alcohol
05:18 PM rue_mohr: but the only way I can pull it off, is with large pots and gears
05:18 PM rue_mohr: and my gear library is a mess, so
05:18 PM aandrew: but taking a mash and doing it properly generates very very little methanol
05:18 PM rue_mohr: I'll just stick to the electronic one
05:18 PM aandrew: rue_mohr: oh yeah, you're going crazy on this
05:18 PM rue_mohr: well
05:18 PM aandrew: I am 100% sure you have some of those crazy decade switches
05:18 PM aandrew: rather than doing it fancy like
05:19 PM rue_mohr: I had the 32 relays
05:19 PM rue_mohr: how can I say no?
05:19 PM rue_mohr: I do, but I'd need a 7 gang one, and it would end up huge
05:19 PM rue_mohr: my target is 1U
05:19 PM rue_mohr: with dual matched outputs
05:20 PM rue_mohr: looks like I might end up with a vfd screen
05:20 PM rue_mohr: I might be finished in sep
05:20 PM rue_mohr: next year
05:20 PM aandrew: that is quite fancy
05:20 PM rue_mohr: but hey!, I ALSO have a large enough set of reed relays to make a capacitor one!
05:21 PM rue_mohr: aandrew, yea, I'm also going atmega8 and usb I/F
05:21 PM aandrew: you can't get away with signal relays for a capacitor one?
05:21 PM aandrew: oh wow
05:21 PM rue_mohr: with 4 memory buttons on the front too
05:21 PM rue_mohr: aandrew, not sure,
05:21 PM rue_mohr: I dont totally need a capacitor one right now
05:21 PM rue_mohr: its a thought
05:22 PM aandrew: yeah I usually have more trouble playing with caps than resistors
05:22 PM aandrew: pots are easy to come by
05:22 PM aandrew: trying to find a good value cpacitor though
05:23 PM aandrew: rue_mohr: if you do it right I could totally see a 4x resistor and 4x capacitor in 1U, USB interface
05:23 PM aandrew: that'd make playing with op amp circuits so much nicer
05:23 PM aandrew: couldn't really do it for high frequencies but it'd be a godsend for playing with analog frontends up to a few MHz
05:24 PM rue_mohr: 28 relays aint small
05:25 PM aandrew: it certainly can be
05:25 PM rue_mohr: ... not with the relays I already have...
05:26 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1150863.jpg
05:27 PM aandrew: yeah those are bigger
05:28 PM aandrew: was thinking something like https://www.digikey.ca/product-detail/en/te-connectivity-potter-brumfield-relays/1462041-8/PB1247-ND/2126943 but even those aren't tiny
05:28 PM rue_mohr: there are definitly better ones
05:29 PM rue_mohr: I suspect I have enough of those from phone pcbs, but dont want to tear them all down
05:29 PM aandrew: https://www.digikey.ca/product-detail/en/comus-international/3570-1331-051/1835-1116-ND/7497098 is getting more the size I was thinking of
05:29 PM * Tom_L opens a jar of butterflies in front of rue_mohr
05:29 PM rue_mohr: yea, (from dk) that ~$150
05:29 PM rue_mohr: hahahaha butterflies!!!!!
05:30 PM aandrew: wow as soon as you step away from 5V coil the price jumps 5x
05:31 PM rue_mohr: heh
05:31 PM rue_mohr: mine are 12V coils, so I'm gonna use a 12V supply
05:31 PM aandrew: yep that Comus TH SIP reed relay is the one I'd go with. PCB routing would be trivial
05:33 PM aandrew: man now I kind of want to hear the clickety-click of dozens of reed relays
05:33 PM aandrew: that little "ting" they make when they open up too...
05:35 PM rue_mohr: :)
05:35 PM rue_mohr: yea, these larger relays will be loud
05:36 PM rue_mohr: esp as I'm implenting an encoder witch
05:36 PM rue_mohr: THO
05:36 PM polprog: haha, this is good
05:36 PM polprog: connected the osc output to a hct14
05:36 PM rue_mohr: I think I shoudl set it up so you have to press 'enter' to activate the new value
05:36 PM Tom_L: rue_mohr, what about these?
05:36 PM polprog: the coupled noise causes the unconnected adjacent inverter to oscilallate :D
05:36 PM rue_mohr: polprog, did it go?
05:36 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/temp/Relay1.jpg
05:36 PM polprog: yep
05:37 PM rue_mohr: yea, HC14 are horrid for crosstalk
05:37 PM polprog: picking an R to have abou 50% duty
05:37 PM polprog: on the BC547 i got bang on 50% with 30k
05:37 PM rue_mohr: Tom_L, heh, those are dated :)
05:37 PM polprog: on the 2n2222 its bit worse, 50% duty is not stable
05:37 PM rue_mohr: polprog, see, its fun to tune now, you will go thru a few dozen working circuits
05:38 PM polprog: yeah
05:38 PM polprog: hey
05:38 PM polprog: thanks ;)
05:38 PM Tom_L: rue_mohr, i took one of those apart for the contacts to fix a dryer relay once
05:39 PM Tom_L: never had a problem with it after that
05:39 PM rue_mohr: :)
05:42 PM rue_mohr: ok there, I modded my tempimage script to handle pngs too
05:43 PM polprog: hmm, cant get above 36% with 2n2222
05:44 PM rue_mohr: you have to load or more or change the bias
05:44 PM rue_mohr: oh duty?
05:44 PM rue_mohr: lets see what your using to "digitize it"
05:47 PM polprog: just straight into the hct14
05:47 PM polprog: ok, got it, 13kohm for 2n2222
05:47 PM rue_mohr: no..
05:47 PM polprog: the output is unlike a sine though
05:47 PM rue_mohr: you want to use a capacitor to couple to the '14, and then add a DC bias
05:48 PM polprog: makes sense, i was thinking about that
05:48 PM rue_mohr: _I_ can never get enough amplitude out of the oscillators, and hav to add a transistor gain stage
05:48 PM rue_mohr: ok, I'm gonna test this motor driver (yikes) and check the mail
05:49 PM rue_mohr: I'v had it with protoboard, I SWEAR it takes me waaay less time to design and make a custom pcb
05:49 PM rue_mohr: I need two of these motor drivers, and I want to just etch the other one
05:49 PM rue_mohr: it took me like 3 days to put this togethor
05:50 PM rue_mohr: I could have a pcb in an evening
05:52 PM rue_shop1: and it saddens me, that it might be true
05:52 PM rue_shop1: a few voltage options might be all I need on a power supply
05:52 PM rue_shop1: 5, 12, 15
05:52 PM rue_shop1: I'm not so sure I need completely variable
05:54 PM rue_shop1: heh, the driver pulls about 100mA idle
05:55 PM polprog: ok... ill get something to eat and go to sleep
05:55 PM rue_shop1: it doesn't seem to be exploding tho
05:55 PM polprog: this is nice
05:55 PM polprog: i wonder what would it take to get tht 40Mhz one chooching
05:56 PM rue_shop1: remember to document them
05:56 PM polprog: i do
05:56 PM rue_shop1: ok, no load switching...
05:58 PM polprog: hmm, 24.5
05:58 PM polprog: 22.1184..
05:58 PM polprog: next thing i should make a PLL
06:00 PM rue_shop1: ok, no explosions with no load
06:01 PM polprog: good job
06:01 PM rue_shop1: small motor is going ok
06:02 PM rue_shop1: heh, well 1.2w idle eh?
06:03 PM polprog: nite
06:10 PM rue_shop1: seems good with a big motor
09:14 PM rue_shop1: welll damnit
09:14 PM rue_shop1: it died from the completely natural failure of the heating element
09:17 PM rue_shop1: ooo but
09:32 PM rue_shop1: ok, if I can weld on this thermal fuse, I'm ok
10:20 PM aandrew: rue_shop1: spot weld?
10:22 PM rue_mohr: yup
10:22 PM rue_mohr: ~1200A
10:22 PM aandrew: How’s it go?
10:22 PM rue_mohr: bzzzt!
10:22 PM rue_mohr: big ass transformer
10:22 PM aandrew: Hahaha
10:22 PM rue_mohr: its a commercial one
10:33 PM Tom_L: sparkie's tryin to light up the sky
10:43 PM rue_mohr: ?
10:44 PM rue_mohr: tea machine is fixed, tea is once again flowing
10:44 PM rue_mohr: I'd like to have added a led and a button, maybe next time
10:45 PM rue_mohr: I need a button solution that doesn't put someone at risk of contact with the 120V unisolated electronics behind it
10:51 PM Tom_L: what's the bigass transformer for?
10:55 PM rue_shop1: its a spot welder
10:55 PM Tom_L: oh
10:57 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1150935.jpg
10:59 PM Tom_L: yeah
11:08 PM rue_shop1: ok, before I was working on the drivers for the mirror...
11:08 PM rue_shop1: oh right cnc drivers
11:08 PM rue_shop1: ok
11:24 PM rue_shop1: ooo 10T is 0.8mH on this core, THATS cool...
11:25 PM rue_shop1: L = N^2*k?
11:26 PM rue_shop3: http://zpostbox.ru/how_to_determine_permeability_of_unknown_cores_online_calculator.html
11:33 PM Tom_L: huh
11:58 PM rue_mohr: zhanx,
11:58 PM rue_mohr: https://twitter.com/ComradeRobot/status/1253906681353789446