#robotics Logs

Sep 23 2012

00:02 Jak_o_Shadows I'd be interested in that last as well.
00:02 home msp430 :P
00:02 home if oly I got the gold
00:04 home I got an Arduino, but I wonder why I would need an msp430
00:05 ace4016 read the datasheet?
00:05 home naaahh
00:05 home actually I am right now..ironically
00:16 rue_shop3 oops what VEE
00:20 rue_shop3 I think VEE can be lower than VSS
00:21 rue_shop3 example, if VDD = 5V, VSS = 0V and VEE = −5V,
00:32 rue_shop3 4532
03:31 rue_house theBear, whats the typ gain on a mic preamp?
03:31 rue_house or is there
03:31 rue_house top end
03:31 theBear umm, jeez, biggish, i'll check a google picture, i've never been big on relating db on knobs to real world stuff in audio land, it's generally unproductive
03:32 GuShH depends on the type of mic!
03:34 theBear grr, stupid people that take pictures ican search on the net
03:34 theBear yamaha seem to suggest from +16 to +60dB
03:35 theBear which would cover everything from a cheap dynamic at some kinda distance from the source with lots of noise, up to a fancy-ass preamplified condesnsor
03:35 theBear oh, i suppose with a -20dB button, but well, you shouldn't need that :)
03:35 rue_house 8x? 10db?
03:35 ShH likes fancy
03:36 rue_house 60db!
03:36 GuShH real men amplify at over 9000dB
03:36 rue_house heh
03:37 rue_house I just need to go from mic levels to 1Vp-p
03:37 rue_house 0dbm
03:37 rue_house .707, whatever
03:38 theBear what kinda mic ? stick it on a scope and calculate needed gain, add a little and have some kind of attenuation/trimmer
03:38 theBear and '0dbv' is VERY ill defined
03:39 rue_house a realistic PZM mic
03:40 theBear oh, those used to be really nice, the big flat boundary ones, from memory yer sposed to change a cap or a resistor to make them IDENTICAL to a REALLY nice mic of the same era... nevertheless, that'll be a condensor with probably a decent amount of output to begin with
03:40 rue_house http://www.ebay.ca/itm/REALISTIC-PZM-Pressure-Zone-Omni-Directional-Mic-Microphone-w-Original-Box-/170901840045?pt=US_Pro_Audio_Microphones&hash=item27ca8b20ad
03:40 rue_house aparently still worth something
03:41 rue_house its got a little battery pre-preamp
03:41 ShH stares at his
03:43 rue_house huh, I have a box of them
03:43 rue_house wonder if thats worth something
03:43 theBear yeah, that's the one, and from memory, it's not a preamp, just bias for the condensor element
03:43 theBear and works MUCH better with something like 48v than 3v
03:43 theBear and yeah, in some circles they are still considered quite desirable
03:44 rue_house huh
03:46 e_house looks at the little
03:46 rue_house never opened it...
03:49 rue_house http://www.ebay.com/itm/Lot-2-Teac-PB-64-Patch-Bay-PB64-Audio-Panel-Rackmount-Soundsystem-Crown-RCA-Jack-/150905032738?pt=US_Cables_Snakes_Interconnects&hash=item2322a41022
03:49 rue_house so there are 256 RCA connectors on that
03:49 GuShH rue_house: mint condition, never opened! rare, collectors item
03:49 GuShH $999.99
03:49 theBear rca patch panel ? what a waste !
03:49 rue_house I could make a HELL of a cross point switch with it
03:50 theBear that looks like it nicely matches their 4/8track 'home studio' series of a similar age
03:50 rue_house 2x16 stereo?
03:50 eBear looks in the lounge
03:50 GuShH used to love teac
03:50 rue_house x4 of course
03:51 rue_house for 8x16 stereo cross point
03:51 theBear too much labelling on it, i think it's a pb16 or so tho
03:51 rue_house I presume its all just straght thru
03:51 theBear for reference that would most likely been a patch bay(s) for a 16 or 32 track machine in a studio too cheap for real jacks and patchbays
03:51 theBear and yeah, it'll be straight thru
03:51 theBear if it had jacks they'd probably be 'auto-normalling' or even switchable
03:52 rue_house whats auto normal?
03:52 GuShH levels
03:53 rue_house dc levels?
03:53 theBear nah, in this case it's switching
03:53 GuShH bear levels!
03:55 theBear ie. you got a 2 'row' patchbay, connected to desk-inserts or between a tape machine and a desk maybe... with nothing plugged in, auto-normal will 'pass through' the signal from top row to bottom row, BUT if you then plug a jack into the 'return'/bottom row, it cuts the signal, so you could 'insert' an effect between top and bottom row, OR just grab a send from top row without cutting the through function
03:55 theBear in patchbay land they call it auto-normalling
03:55 rue_house wonder how cheap I can get one of the mixer things with the motorized knobs
03:55 GuShH if i had a truck I'd be a motorized knob
03:55 rue_house wait, I dont have room
03:56 theBear you can probably get an old one with shitty audio section (like sub cd quality) for a couple hundred, one that's pretty good for maybe a grand or so... personally i'm fond of the yamaha 01v series for small stuff
03:56 rue_house and I'm already building a 1x8 stereo switch to switch between TWO audio sources
03:56 theBear consider also that a semi-modern unit like an o1v includes at least 20rack units of various dynamics eq and/or effects inside it
03:58 rue_house there is a link called "save this seller" but they dont say what I'm to be saving them from
03:58 rue_house http://www.ebay.com/itm/2-pcs-RCA-Type-Audio-In-Outlet-Panel-Gloden-8P-WONDER-/140308558066?pt=LH_DefaultDomain_0&hash=item20ab0ab0f2
03:59 rue_house I think thats overpriced
03:59 rue_house w/shipping
03:59 theBear release bill posters !
03:59 rue_house basically $5 ea
03:59 GuShH you need them with the panels?
04:00 rue_house I thought to replace the two I'm using up for the 8x1 switch
04:00 GuShH otherwise for 4 bucks (incl. shipping) you can get 8 RCAs
04:00 GuShH >_<
04:00 rue_house thats $10 for 16 RCAs
04:01 GuShH and my offer is 8!
04:01 GuShH you could buy theBear a beer with the remaining $2
04:01 rue_house the patch panels are .31c ea RCA
04:01 theBear i could really use it today !
04:01 GuShH me too
04:02 GuShH I even ran out of coffee.. how does that even happen
04:02 theBear heh, i'll swap you 2 of my last 3 cups worth of beans (ground or unground, at your option) for $3.99 to buy a bottle of cheap blended wine for the day !~
04:03 theBear i can even supply a small amount of milk, sugar, cocoa, cinnamon and/or nutmeg
04:03 GuShH Do we use the pneumatic tubes to perform this transaction?
04:03 rue_house Yellow RCA jacks seem to be going cheap, its like there isn't a use for them all of the sudden
04:03 theBear i dunno what you use, but i just flipped open a cover under my desk and put 2/3rds of my coffee supplies in it, then heard a "fwoooomp" sound
04:03 theBear so umm, pony up <grin>
04:04 GuShH you can paint them black or red!
04:04 GuShH lol
04:04 rue_house or white?
04:04 GuShH I did... but I think that tube connects to the shopvac
04:05 theBear hmmm, any coffee come out of it ?
04:05 eBear feels that he and GuShH may have just made a horrible mis
04:05 GuShH I think it got stuck with the pennies
04:05 rue_house the bottom is falling out of the USD during their election
04:05 theBear how can the bottom fall out of something that already lacks a bottom ?
04:05 GuShH your belly button holds your bottom!
04:05 GuShH it's a screw.
04:06 theBear heh
04:06 rue_house ok, well
04:06 GuShH here, let me show you
04:06 rue_house the circuit seems to work
04:06 ShH grabs the drill and chases rue_house around wit
04:07 rue_house its just a bit dodgy where the 4532 triggers the clock of the 4042 to latch the bits to the 4511/4051
04:07 GuShH I still smell like castor oil after fooling around with my little cox 0.49 yesterday...
04:07 rue_house heh
04:08 GuShH amazing how the nitro fuel still works after so many years
04:08 rue_house I found my 049 engines yesterday
04:08 GuShH I think it's this modern stuff, in the old days nitro fuel was crap, you even had to filter it several times
04:08 GuShH rue_house: I need adapter heads :(
04:08 rue_house wonder if the bottom rusted out of the fuel can yet
04:08 GuShH wish I had a lathe!!
04:09 GuShH rust... my little handcrank fuel pump had a rusted axle, fixed it.
04:09 rue_house I meant to make a gen set with it
04:09 GuShH LOL
04:09 GuShH loudest than a big ass real genset!
04:09 rue_house something for charging batteries on a robot
04:09 GuShH louder*
04:09 GuShH rue_house: the whole setup of the engine makes it quite not ideal
04:09 rue_house but 40x more fun
04:10 GuShH my glow head doesn't have much left in it, that's why I want the adapter ones so I can use regular glow plugs
04:10 GuShH people are selling kits to convert them into "diesel" too
04:10 rue_house just use a torch lighter and heat the snot out of the electrode
04:10 theBear pfft, they're 2 strokes, they are diesel :)
04:10 GuShH basically an adjustable head and new internals
04:11 GuShH theBear: it is like a diesel, since it uses a glow plug..
04:11 GuShH but I meant without requiring pre-heating
04:11 GuShH right now I'm using several amps to make it glow before I can start it
04:11 rue_house isn't that normal?
04:12 rue_house I'm asleep and I havn't noticed yet
04:12 GuShH yes, but you can convert them into not having to use pre-heating!
04:12 theBear wtf ? how ?
04:12 GuShH higher compression
04:12 theBear heh, that's getting a bit carried away on a tiny head like that
04:12 GuShH and using a diesel-like fuel mix instead of the regular nitro
04:13 GuShH hey it works, but I found the kits to be way too expensive for me
04:13 theBear pfft, if old coaster busses can still run fine on glowplugs, i don't see any reason not to use them
04:13 GuShH well, having a lathe only solves half the problem... you'd still need a milling machine to make this kind of stuff
04:14 GuShH I read a document on the guy behind the first cox engines
04:14 GuShH pretty interesting stuff
04:14 Jak_o_Shadows .
04:14 Jak_o_Shadows .
04:14 GuShH http://www.youtube.com/watch?v=v0ilSkRq0PU
04:14 GuShH diesel converted 049
04:14 GuShH seems to be running way too rich
04:15 GuShH or way too big a prop
04:15 GuShH but, you can see the adjustable head
04:15 GuShH they've made throttle rings, exhausts, all kinds of shit for these toy engines
04:16 GuShH even carb / ring combos that could be controlled by a servo
04:17 GuShH rue_house: example of a modded 049 http://www.youtube.com/watch?v=TJjLg-67m1o
04:18 rue_house mm
04:18 GuShH too bad most of these guys sound like 10 year old druggies
04:18 theBear err, wtf is that video more than 5 seconds long ?
04:20 rue_house gooood question!
04:20 GuShH this one is 28 seconds long! http://www.youtube.com/watch?v=XDEa0kZVNn8&feature=related
04:21 GuShH holy shit http://www.youtube.com/watch?feature=endscreen&v=HG8F-wQYeK0&NR=1
04:21 theBear nah, i had enough put put put for today, i know what a tiny 2stroke sounds like, and apart from glimpsing that head, words are more than enough
04:21 GuShH wait, why does it sound like a 4 stroke?
04:21 GuShH it's got 4 cylinders!
04:22 theBear damn that was loud and annoying
04:22 theBear just use words, or you're no better than the rest of them
04:22 GuShH o.o
05:06 GuShH rue_house: what's your wifi network name?
05:07 GuShH mine is "FBI Surveillance Van"
07:00 theBear why does that sound familiar ? i'd swear i'd seen a (stupid) thread somewhere where someone saw that ssid and assumed it was 'real'
07:22 GuShH theBear: no clue
07:23 GuShH but if there are paranoids around...
07:25 GuShH I wonder what's used as an additive to make chain/bar oil so sticky
11:47 rue_bed the "fbi surveylance van" joke is taking the internet by storm, thats the 3rd time in a week I'v heard it
11:57 home What
11:57 home WHAT?
11:58 rue_bed or am I getting the timeline mixed up again
11:59 home no
12:01 ace4016 rue_bed, you're a little late...been around since I was still at uni
12:31 rue_bed wow, all the way to australlia, some things I will just never understand
12:31 Tom_itx how you comin on your reprap?
12:38 rue_house damned firmware
12:45 rue_house I'm gonna go around the firmware problem by working on the stepper controllers, thanks for reminding me
12:45 rue_house I have some tiny26 code to write
12:45 rue_house need a shower first
12:45 home :/
12:46 rue_house I dont think I opened yesterdays ebay item
12:47 rue_house sweeeeeeeeeet CD4046 (x2)
12:48 home rue_house: gimme
12:49 rue_house NO! I'm gonna make an audio fm carrier with them
12:51 rue_house I still need to play with the maxim display chip I got
12:52 Tom_itx you should stop fighting things that can be fixed and get on with making stuff
12:52 rue_house yesterday I made great progress on a 8 way stereo audio switch
12:54 rue_house once I accepted I had to have a dual rail supply it was easy
13:15 rue_house I'm wondering what to do with the off switch
13:15 rue_house I'm thinking of just disabling the output
13:16 rue_house cause the power switch on it isn't 120V rated
13:19 e_house thinks about attaching a wire ladder to the back of his comp
13:35 rue_house damn, the tiny26 only has one interrupt source
13:35 rue_house pin
13:37 rue_house ah it has pin change interrupt tho
13:46 Tom_itx triggers on both edges
13:52 rue_house thats ok, I have code for that
13:52 rue_house not sure about using a tiny26 to stequence motors for a mega2560, oh well
15:51 katsmeow-afk A NATURAL PAIRING A data center in Ashburn, Va., seen past a Dominion Virginia Power substation serving it. Worldwide, such centers use the rough equivalent of the output of 30 nuclear power plants.
15:51 home What
15:51 katsmeow-afk i said : A NATURAL PAIRING A data center in Ashburn, Va., seen past a Dominion Virginia Power substation serving it. Worldwide, such centers use the rough equivalent of the output of 30 nuclear power plants.
15:52 home What?
15:52 katsmeow-afk i said : A NATURAL PAIRING A data center in Ashburn, Va., seen past a Dominion Virginia Power substation serving it. Worldwide, such centers use the rough equivalent of the output of 30 nuclear power plants.
15:53 katsmeow-afk according to recent disclosures, Google�s data centers consume nearly 300 million watts and Facebook�s about 60 million watts.
15:55 rue_house cmos would have more switching noise as its totempole outout woulnd't it?
15:56 rue_house 300 millions watts and they cant even give me results for what I asked for
15:56 katsmeow-afk hence i want a box that powers ONLY harddrives, keeping the FAT for them in ram, so a drive may eat 10 watts, i do not need a whole puter pulling another 100 watts to mind it
15:56 katsmeow-afk cmos has less noise because it switches more slowly
15:57 rue_house what happens if the ram drops out?
15:57 rue_house oh
15:57 katsmeow-afk in the time cmos goes 1 to 0, ttl may toggle 5x, and ecl may toggle 20x
15:57 katsmeow-afk if the ram drops out, access gets down to more normal seeds
15:58 katsmeow-afk speeds
15:58 home What?
16:00 katsmeow-afk speeds
16:01 katsmeow-afk home apparently has no clue how to scroll up, i should put that moron on ignore too
16:04 theBear scroll up ? it was only one line back !
16:04 rue_house so then, point in hand, I dont need to go crazy on the digital decoupling for my audio circuit
16:05 rue_house I have distributed 3uF so far
16:06 katsmeow-afk use ceramics, or tant caps, anything with low esr, and proper gnd layout, and you're fine
16:06 rue_house kat do yo have a min to look at a design problem for me?
16:07 katsmeow-afk yeas
16:07 rue_house something didn't work out like I expected and I wants to know if I'm just being crazy
16:07 katsmeow-afk "being crasy" and "working thngs out" can be done at the same time, yanno
16:07 rue_house ok, 4532 is a priority encoder, my selection buttons go into it, 4042 is a quad D latch I use to hold the results onto the 4051's
16:08 katsmeow-afk ok
16:08 rue_house the 4532 outputs 3 bits, and 2 complimenrary "there is an input" signals
16:08 katsmeow-afk you are making a "who pressed the button first" thing?
16:08 rue_house the 4042 is tooo flexable and has a "polarity" control on the D clock for edge selection
16:09 rue_house no, this is for the audio selector
16:09 katsmeow-afk k
16:09 rue_house 8 buttons to select the channel you want to direct
16:09 rue_house so
16:09 rue_house the conclusion _I_ came up with to hook the two togethor so that the 4042 would latch the 4532's signal was...
16:10 rue_house to ground pin 6 of the 4042
16:10 katsmeow-afk 4042?
16:10 rue_house and hook pin 5 to pin 14 of the 4532
16:11 rue_house and hook pin 5 of 4042 to pin 14 of the 4532
16:11 katsmeow-afk show me a schematic
16:11 rue_house schematic I changed pin 6 to tie high
16:12 rue_house mm see if this card reader really works ..
16:14 rue_house yay it worked
16:14 katsmeow-afk i'd have done something different, the 4532 is a priority encoder, not a "which one" encoder, and then you use a fet switch that needs pre-latched encoded inputs
16:14 rue_house have to convert to binary for the 4051
16:15 rue_house !assist images/p1040617.jpg
16:15 tobbor Possibly http://eds.dyndns.org/~ircjunk/images/p1040617.jpg
16:15 katsmeow-afk yrs ago you (or was it me?) did a 1-of-8 using common 4016/4066/etc and one octal latch
16:15 rue_house I think this should work
16:15 rue_house I have a 4511 in there to display the active channel
16:16 rue_house with pin 6 tied low, it didn't seem to be latching properly, but I dont know if it was a breadboard problem or a design problem
16:16 rue_house I looked at it 3 times, and I was sure that it should go low
16:17 katsmeow-afk hence, a scope
16:17 rue_house when I put the probe on the pins all the behaviour changed
16:17 katsmeow-afk that's a serious problem
16:17 rue_house would you take a look at the 4532 and the 4042 and see if you can work out how you would link them?
16:18 rue_house huh, no DP output on the 4511....
16:18 rue_house theBear, katsmeow-afk I'm also wondering what RC I should use on the input for dc reject
16:20 rue_house I'm thinking maybe 470k to ground w/ 4.7uF thru
16:20 katsmeow-afk why would there be any dc?
16:20 rue_house just in case
16:21 rue_house I think I might have to add a rc delay between the 4532 and the 4042 to make this work reliably
16:21 katsmeow-afk 4.7u and 470k roll off is under 1hz
16:22 rue_house I dont mind losing sub 1Hz
16:23 katsmeow-afk i mean you might wanna lower the R or the C to roll it off higher if you are doing only speech
16:23 rue_house no its for music
16:23 katsmeow-afk ah
16:24 katsmeow-afk i'd use more cap, i'd even use opamp buffers, driving the 4051/7451 from a 10k source will roll off the high end a lot
16:24 rue_house http://sim.okawa-denshi.jp/en/CRtool.php
16:24 theBear what ? it's 5am mondya, i gotta have me anap before work err... errr gnight :)
16:24 rue_house ooo
16:24 katsmeow-afk gnites, bear
16:24 rue_house Cut-off frequency
16:24 rue_house fc = 0.0720484124454[Hz]
16:24 katsmeow-afk yeas, under 1hz
16:25 katsmeow-afk i didn't know what you were filtering, other than dc
16:25 rue_house cool
16:26 rue_house I'm gonna go solder!
16:26 katsmeow-afk i don't see why touching a probe to anything should affect it
16:26 rue_house I'm going to assemble this to see how it behaves, the 4532 / 4042 thing is bugging me tho
16:26 katsmeow-afk even debounce on the switches should be ok with a probe touching it
16:26 rue_house bounce shouldn't be an issue
16:27 katsmeow-afk you have not assembled it? then how do you know touching it with a scope probe affects it??
16:27 rue_house cause it would be the same signal each bounce
16:27 rue_house I breadboarded it
16:27 katsmeow-afk oh
16:27 rue_house my conclusion was to buy some better breadboards
16:27 rue_house :)
16:28 katsmeow-afk well, at 5v, the clk input to the 4052 hasto be 1/2 us long,,, bounces *might* be faster,,
16:28 rue_house ah
16:28 rue_house maybe .01uF on the buttons would be wise
16:28 katsmeow-afk add some .01's to the inputs on the 4532?
16:28 katsmeow-afk yeas
16:28 rue_house :)
16:31 katsmeow-afk i have not used the 4051,2,3 , i have used the much faster 74ls5_ switches, and they really don't like glitchy clocks, however, they also have onboard latches
16:33 rue_shop3 :/
16:33 katsmeow-afk not that it matters, but i'd have used a octal latch with a clr input, hold clr active during poweron/off, use a high value resistor feed back output-input on each flipflop, and the pushbutton overrides each with a low value R and triggers the clk on the latch at the same time
16:34 katsmeow-afk presto, in one chip you have pwr on/off auto-mute, latching, and debounce
16:35 katsmeow-afk and you can daisey chain as many as you want
16:35 katsmeow-afk it won't encode, of course
16:46 rue_shop3 you mean buffer dont' you?
16:46 rue_shop3 you use a buffer with a feedback resistor and make the input current override the feedback from the output?
16:47 rue_shop3 5-2.2/0.20
16:47 rue_shop3 13 ohms!
16:47 rue_shop3 ok, 14 but !!!!!!!!!!!!!
16:48 rue_shop3 ok, hmm
16:48 katsmeow-afk what is 13 ohms?
16:49 rue_shop3 man 4710 7 segment on 5V
16:50 rue_shop3 the spec says they drop 2.2V and run at 20mA
16:51 rue_shop3 at 47R it starts to look the right brightness tho
16:55 rue_shop3 meter says 47R is 64mA, so there goes more math out the window
16:55 rue_shop3 160R is 20mAish
16:57 rue_shop3 VOl of of the 4511...
16:58 rue_shop3 really low
16:58 katsmeow-afk 45xx family != 40xx family
16:59 rue_shop3 yea, bit of a mix here
16:59 rue_shop3 why is the 4511 only rated to 4.5mA on its outputs...
17:00 rue_shop3 datasheet also says 25mA
17:00 katsmeow-afk becasue they think you'll drive only more cmos with it
17:00 rue_shop3 must be the other outputs
17:00 rue_shop3 4511 is direct drive
17:01 rue_shop3 ooooh
17:01 rue_shop3 hmm I need a common cathode display
17:02 rue_shop3 3.75V out when direct drive
17:03 e_shop3 checks the drop onteh dis
17:03 rue_shop3 1.6
17:04 rue_shop3 107 ohms
17:04 rue_shop3 ok
17:04 rue_shop3 need to find a cathode display
17:04 rue_shop3 I think I ahve one
17:10 rue_house any ideas on matching th clocks for the 4532 and 4042?
17:10 katsmeow-afk i wonder where i'd find 100's feet of 20-2 , 22-1 , 24-2 etc wire
17:10 katsmeow-afk matching them ?
17:11 katsmeow-afk are you saying the 4532 won't drive the 4042 input?
17:13 katsmeow-afk EMC and the International Data Corporation together estimated that more than 1.8 trillion gigabytes of digital information were created globally last year.
17:16 rue_house well it looks like I didn't get the polarity mathup right
17:17 rue_house matchup
17:17 rue_house I prolly want the edge that happens AFTER the data is valid, aka when its going invalud
17:18 rue_house so, say a rising edge
17:18 rue_house then its just a matter of selecting the right 4532 output
17:19 tsmeow-afk
17:24 rue_shop3 I have a TIL308
17:24 rue_shop3 wonder if I should just use that
17:25 rue_shop3 haha it exposes its internal latch
17:40 rue_shop3 I could use something other than a 4511
17:51 rue_house cmos -> ttl should be ok tho
17:51 rue_house its ttl->cmos that would need adjusting
17:53 rue_house so I can ditch the 4511 and use a ttl that will work ok with common anode
18:59 rue_shop3 ok, shopping is done
18:59 rue_shop3 who does common anode, 7447 or 7448
19:00 rue_shop3 7447 is common anode
19:01 rue_shop3 7448 is common cathode
19:02 katsmeow-afk you don't *need* an open collector driver for an led
19:02 rue_shop3 inverted outputs
19:02 katsmeow-afk anything that pulls up can pull up an led
19:03 katsmeow-afk so 74244 vs 74245 <shrug>
19:03 katsmeow-afk sorry, my mind is all over something else atm
19:04 rue_shop3 :)
19:05 rue_shop3 ttl driving to ground is ofcourse a good way to get your current
19:06 rue_shop3 I have to re-sort the CMOS, 4001 to 4581 is only spread across 6 drawrs
19:08 rue_shop3 7447 loses at most .5V
19:08 rue_shop3 so 100 ohms should do
19:09 rue_shop3 technically 132 ohms
19:10 katsmeow-afk pwm it, so when the room lites dim, the display does too
19:11 katsmeow-afk you can pwm the 7447 inputs, or the common on the led display
19:11 katsmeow-afk pwm the OE pin of the latch before the 7447
19:47 rue_shop3 :( my smt resistor fell thru a hole in the verobaord, I cant find it
19:49 e_shop3 squints at another motherbaord for a 301 or
19:49 Tom_itx i've sucked a few up in my pick n place
19:49 rue_shop3 or EOI
19:50 rue_shop3 Tom_itx, :)
19:50 rue_shop3 SLURP... oops..
19:50 Tom_itx just the 0402's
19:50 Tom_itx the 0603's won't fit thru the needle
19:51 Tom_itx and i quit using 0402 for the most part lately
20:02 katsmeow-afk this is informative : http://s3.documentcloud.org/documents/438380/medicare.txt
21:08 rue_shop3 current is spot on
21:08 rue_shop3 150R 3V across the 150R is .02A
21:08 rue_shop3 but when I strobe the inputs it gies me 2, 3, 2, 3, 4, 5, 4, 5
21:10 katsmeow-afk the encoding is wrong??
21:15 rue_shop3 oops, I missed pins 10, 11 I used 11,12
21:15 rue_shop3 on the 4042
21:17 rue_shop3 yaaay!
21:17 rue_shop3 I can strobe thru with a wire and the display indicates the right thing
21:18 katsmeow-afk It cost $3.5 billion to construct NIF, with 192 laser beams. However, for fiscal year 2013, the project will receive only $84 million, $26 million less than last year. In short, the Feds have warned LLNR, get net positive this coming year or face further cuts.
21:19 rue_shop3 so much for fusion
21:19 rue_shop3 kat, do you know a small trick for making a T flipflop for a mute?
21:20 rue_shop3 there is this inhibit signal on the 4051 I'm buring to use for it
21:20 katsmeow-afk other countries will do it, Russia is building a plant 50% bigger, other countries have been working on it, china, etc
21:20 rue_shop3 the usa cant even get into space right now :)
21:20 katsmeow-afk in doing a what?
21:20 rue_shop3 a toggle for a mute button
21:20 katsmeow-afk you can get toggle switches
21:21 rue_shop3 I think a 4013 with /Q tied to D is the best I'm gonna get
21:21 rue_shop3 no I have buttons
21:21 katsmeow-afk if you mean a flipflop, use 2 transistors and some other parts, or 2 nand gates or a flipflip
21:21 katsmeow-afk ok
21:22 rue_shop3 a tiny13 only takes up 8 pins of space
21:22 rue_shop3 hey Tom_itx ! its a job for a tiny10!
21:23 Tom_itx heh cool
21:23 Tom_itx i knew you'd find a use for one
21:24 rue_shop3 hahah the power switch is a toggle, I could make it kill the display power and mute the output
21:25 rue_shop3 then it will "remember" the channel you left it on
21:25 rue_shop3 I wonder how long a CR2032 can power a 4042 for
21:26 rue_shop3 ok later
21:27 katsmeow-afk hmm, cocaine has 288 mg of caffine in a 8.4 oz serving size
21:27 katsmeow-afk no wonder so many people do coke
21:28 rue_shop3 tom, weren't the jets that obama put a stop to for the CEOs of the companys that had just recieved the bailout money?
21:29 rue_shop3 damn, 18 dc filters
21:29 rue_shop3 thats a whole nother pcb
21:29 rue_shop3 I want to protect the switches
21:29 rue_shop3 how about just 1k resistors?
21:30 rue_shop3 hmm still, static
21:30 Tom_itx rue_shop3, just his announcement caused companies to cancel orders
21:30 katsmeow-afk too low, your 10k or 50k audio sourse will not drive 1k very well
21:30 rue_shop3 then again, is a low pass gonna protect a cmos chip from static? prolly not
21:30 Tom_itx or put them on indefinite hold
21:30 rue_shop3 no I men in series
21:30 katsmeow-afk err,oh
21:30 rue_shop3 the cmos has diodes on its inputs right?
21:31 rue_shop3 so if the resistor limits the current and the diode shunts anythnig that shouldn't be there, everyone is happy?
21:31 rue_shop3 iirc the signal connects before the ground on an RCA
21:31 rue_shop3 (which is kinda stupid)
21:32 rue_shop3 4.7uF and 470k
21:32 rue_shop3 x 18
21:35 rue_shop3 or.. maybe that not a problem, these drawrs have more stuff in them than it looks
21:45 rue_shop3 would it matter if I use a polorized cap? I dont think so,
21:45 rue_shop3 there should never be any voltage across it
21:48 rue_shop3 0.1uF is the largest nonopolar I have enough of
21:49 katsmeow-afk too small
21:49 rue_shop3 I think polar will be ok
21:50 rue_shop3 I'm sure they use polar on commercial stuff
21:52 rue_shop3 if I assume the out is loading to ground
21:52 rue_shop3 then the inputs are positive
22:18 rue_shop3 ok thats that made
22:18 rue_shop3 the look of the dc refjection baord is making finishing this looking daunting
22:19 rue_shop3 I'm calling it a night tho
22:19 rue_shop3 I need to make supper and go to bed
22:19 rue_shop3 and write stepper motor sequence code for the reprap
22:19 rue_shop3 I'll take pics of my work so far
22:19 rue_shop3 ont eh baords
22:22 rue_house I'd have etched this, but I didn't want to draw it out
22:26 rue_house !assist projects/audioswitch
22:26 tobbor Possibly http://eds.dyndns.org/~ircjunk/projects/audioswitch
22:26 rue_house http://eds.dyndns.org/~ircjunk/projects/audioswitch/p1040619.jpg
22:26 rue_house http://eds.dyndns.org/~ircjunk/projects/audioswitch/p1040620.jpg
22:27 katsmeow-afk oh yeas, food, i knew i was forrgetting something aian
22:27 rue_house do the boards look cute?
22:27 rue_house I'd take a pic of the back to see the smt resistors, but they wouldn't come out on account of their lack of bigness
22:29 katsmeow-afk pretty pics!
22:29 rue_house the control board is a bit sparse, but thats been to my advantage down the road on a few projects
22:29 katsmeow-afk why are the caps on the bottom?
22:29 rue_house thats the top
22:30 katsmeow-afk why are the chips on the bottom?
22:30 rue_house white silkscreen
22:30 katsmeow-afk http://eds.dyndns.org/~ircjunk/projects/audioswitch/p1040620.jpg <<== not the pcb bottom?
22:30 rue_house no, both are top
22:31 katsmeow-afk how did you figure on 18 audio inputs?
22:31 rue_house its not wire wrapped
22:31 rue_house 8 stereo channels and 2 outputs
22:31 katsmeow-afk ah
22:31 rue_house er 1 stereo output
22:32 katsmeow-afk i think you can at least add a dual opamp to compensate for the high freq rolloff you'll get thru the fet switches
22:32 rue_house below the word backup you can see my trace layout for the 74574 state machine board
22:32 katsmeow-afk plus, the fets are good for (at best) 80 ohms of droppage
22:33 rue_house I thoutht the 4051 was 4 ohms
22:33 katsmeow-afk so the opamp can cover over some fet issues
22:33 katsmeow-afk 4 at +/- 15, maybe
22:33 katsmeow-afk not at 5v
22:34 katsmeow-afk Low �ON� resistance: 80� (typ.) over entire 15Vp-p
22:34 katsmeow-afk signal-input range for VDD . VEE = 15V
22:34 rue_house oops, 120R
22:35 rue_house ?
22:35 katsmeow-afk VDD = 7.5V,
22:35 katsmeow-afk 210 80 240 300 �
22:35 katsmeow-afk VEE = .7.5V
22:35 katsmeow-afk or VDD = 15V,
22:35 katsmeow-afk VEE = 0V
22:35 rue_house I'm vdd 5V vee -5V
22:35 rue_house 10R or 120R
22:36 rue_house 120R
22:36 rue_house hmm
22:36 rue_house what a 4066!?
22:36 katsmeow-afk hmm?
22:37 rue_house 120R
22:37 rue_house but...
22:37 rue_house I was sure one of them was better than that
22:37 katsmeow-afk anyhow, drive the input of an opamp after the 4051, and don't worry about the fet resistance, and add some freq compensationa nd output drive current, and you'll be all happier with it
22:37 rue_house maybe I should buffer the outputs
22:38 rue_house I'll try it like this first, I like the fact this can, as it stands, be 8->1 or 1->8
22:38 katsmeow-afk k
22:39 rue_house hmm