#garfield Logs

Dec 19 2013

00:27 katsmeow-afk Tom, can you route/mill the black ink on the dirty-white buttons on http://www.ridgeequipment.com/images/27B92AParts-11-25main.JPG ?
00:28 katsmeow-afk rue, it may be fast
00:28 rue_mohr2 faster than the shotkey that only drops .55V at 2A?
00:28 katsmeow-afk if you ever scope a MDA2500 or 1N4001 , you see it won't run on when it should, and it won't turn off when it shoud, wasting power and heating itself
00:29 rue_mohr2 oh
00:29 katsmeow-afk well, the UF5401 is bloody fast, and isn't schottky, iirc
00:29 rue_mohr2 http://www.aliexpress.com/item/500-pcs-Free-Shipping-SR260-DO-15-2-0-AMPS-SCHOTTKY-BARRIER-RECTIFIERS-MIC/648970689.html
00:29 rue_mohr2 specs on these are nice
00:30 katsmeow-afk "specs" of 2amps and nice price? shockeys are natively only 40v, yanno?
00:31 rue_mohr2 I have datasheet
00:31 katsmeow-afk ok
00:31 katsmeow-afk UF5401 are 3amp and 400v, and switch at 50ns
00:31 rue_mohr2 they varry from 20V to 60V
00:32 katsmeow-afk yeas, i remember when they got them past the 21v "barrier"
00:32 rue_mohr2 interesting, there are no times in this datasheet
00:32 katsmeow-afk see how much they want for any UF series, UF4004, for instance
00:33 rue_mohr2 when did diodes get this interesting naming scheme?
00:33 rue_mohr2 same price in volumes of 1000
00:34 katsmeow-afk ebay 100 UF4004 $4 , free s&h
00:34 katsmeow-afk the UF ? "ultrafast" a couple decades ago
00:34 rue_mohr2 yea HER high eff rectifier, SR shottkey recifier
00:35 rue_mohr2 up to 1.7V loss at 1A
00:35 katsmeow-afk when the diode being so slow you had to allow for it at 60hz
00:44 katsmeow-afk Tom the reason i ask is the 7B92 and 7B53 had those buttons lit so you could read which position they were in, and those two time bases are rare for that reason,,, the buttons come off, and the 7B92A/7B53A could have fiberoptic implanted into them fairly easily
00:51 rue_mohr2 wow
00:51 rue_mohr2 check out ksp13 its a to-92 darlington, gains between 5k and 20k
00:52 katsmeow-afk yeas, the MPSA/KSP lines is pretty good
00:53 rue_mohr2 are the prefixes equivilent?
00:53 katsmeow-afk [23:01] <katsmeow-afk> in the MPSa line i like the 42/92 , the 25/64
00:53 katsmeow-afk different companies
00:53 katsmeow-afk M = motorola, i think all the K are korean
00:53 rue_mohr2 ksp is made by fairchild...
00:53 katsmeow-afk however, motorola no longer makes them, they are allmade in asia anyhow
00:54 katsmeow-afk ditto fairchild
00:54 rue_mohr2 if a darlington transistor loses up to 4V CE I sure the hell dont want to make an H bridge with them
00:55 katsmeow-afk true, but some lose only 2v @ 10amps ;-)
00:55 rue_mohr2 ok, so to make an H bridge, say, 5A target
00:56 rue_mohr2 what do you suggest?
00:56 rue_mohr2 TIP147?
00:56 rue_mohr2 tip32?
00:56 katsmeow-afk 147/147
00:56 katsmeow-afk oheh
00:56 katsmeow-afk 147/142
00:57 katsmeow-afk is below 2v out to 10amps, which is not all that easy to accomplish even with two descrete transistors
00:59 katsmeow-afk at 6amps, you can get the TIP122 downto 1.6v , again, very good for a darlington , the mating part, TIP127 isn't so good tho, at 6amps it's best is 2v
01:00 katsmeow-afk if you must drive heavy currents with a darlington, the best driver would be the TIP122 @ 4amps, which pulls downto 1.3v
01:00 rue_mohr2 isn't the 122 what I just had...
01:01 katsmeow-afk if you hang up some TIP35/36 and pull on their bases with tip122, you prolly have the best of any bipolar design
01:01 rue_mohr2 oh they are 112
01:02 katsmeow-afk tip112 ?
01:02 rue_mohr2 bunch of them on a printer baord
01:02 katsmeow-afk 2amp
01:02 rue_mohr2 35, 36 eh
01:03 katsmeow-afk yea, Vsat on a 112 sucks
01:04 katsmeow-afk it's a prtty fast transistor tho
01:04 rue_mohr2 http://www.aliexpress.com/item/50pcs-TIP35E-TIP35-Amplifier-Power-Transistor/1400987794.html
01:04 rue_mohr2 not cheap
01:05 katsmeow-afk they appear on ebay cheap occasionally, they are hard to pop
01:05 rue_mohr2 er, yea
01:05 rue_mohr2 they are tank form factor :)
01:05 katsmeow-afk heh
01:06 katsmeow-afk really, they are used in capacitive discharge nicad short-blowers, for instance, 100amps for microseconds
01:07 rue_mohr2 well thats tjust the alternate case to a to-3
01:07 rue_mohr2 you just cut the middle pin off and fold it over
01:07 katsmeow-afk who made your 112 ?
01:07 rue_mohr2 dont remmeber
01:08 katsmeow-afk yeas, but if you push the tank form to the top of the to-3 power level, you beter pay good attention to how it's mounted, it's got less dissipation, for real
01:09 katsmeow-afk like a IRF1404, sure you can push 20amps thru it,. but you do that for a minute at 20v across it, and the 400watts will melt it
01:10 katsmeow-afk anyhow OnSemi specs , which i just got, beat MOSSpec specs on the 112 all to heck
01:10 rue_mohr2 hmm
01:10 rue_mohr2 3055 with fet CB drivers?
01:11 rue_mohr2 na, the whole idea is to avoid fet gate driving
01:11 katsmeow-afk if you need a dead slow 60v fet gate, sure
01:12 katsmeow-afk the on datasheet : http://www.alldatasheet.com/datasheet-pdf/pdf/12667/ONSEMI/TIP112.html
01:12 katsmeow-afk ON is the immediate successor to Motorola, who designed the TIP series
01:12 rue_mohr2 oh,
01:12 rue_mohr2 TLP250
01:13 katsmeow-afk i dunno it
01:13 rue_mohr2 opto with fet driver output
01:14 katsmeow-afk in the 1970's the usa companies were riding high and putting out golden stuff, in the 1980's stuff tanked financially and got sold off to avoid bankruptcy
01:14 rue_mohr2 odd, I think they cost mroe than high side driers
01:15 katsmeow-afk the cpu/controller, pal, pga/fpga saved some of them
01:16 rue_mohr2 yea, they are 4x the price of high side drivers
01:16 katsmeow-afk if intel had not come out with 5000 versions of the 8008, they'd have died too
01:16 katsmeow-afk drat it, i didn't finish eating, and it's cold and 1 am
01:16 katsmeow-afk arg my neck hurts
01:16 tsmeow-afk eats a
01:16 rue_mohr2 IR2110 is a high/low side fet driver?
01:17 rue_mohr2 I swear I have a bunch of those somewhere
01:17 tsmeow-afk doesn't know her fets as well as her bipo
01:18 rue_mohr2 its driving the damn things
01:18 katsmeow-afk in the 1980's when i had acess to so much, fets sucked and blew smoke a lot, and just didn't do what they were supposed to at the power and frequencies i was working at
01:19 katsmeow-afk yeas, they still have huge gate capacitances
01:19 katsmeow-afk the trade off is often "do i drive 10amps at 10v to a mosfet, or 10amps at 1v to a bipolar?"
01:20 katsmeow-afk only if it *must* be super low power gate/base drive at dc would i use a mosfet, or if i *must* have very very low Vsat specs
01:20 rue_mohr2 new fets seem to excel at low voltage stuff
01:21 katsmeow-afk so do some bipolars
01:21 katsmeow-afk there's some .2 Vsat bipolars out there, that's like a 2 ohm fet at 100ma
01:22 rue_mohr2 IR2101 is a good deal
01:22 rue_mohr2 ~50c ea
01:22 rue_mohr2 drives a high and low side
01:22 katsmeow-afk not that many to-92 fets below 2 ohms, or cheap ones
01:22 rue_mohr2 no, not small ones
01:22 rue_mohr2 I dont understand why they dont make a to-92 hexfet, 1A or soemthing
01:23 katsmeow-afk right, you haveto goto 50cent to220 / 226/ etc
01:24 katsmeow-afk in the mosfets, it's still a price-performance issue, IRFZ44 are 1/2 the price of IRF1404, and they have 2x the resistance, but it stil beats bipolars at low freqs
01:25 rue_mohr2 http://eds.dyndns.org/~ircjunk/circuits/fetdrive.gif
01:25 rue_mohr2 I was having a hard time measuring any switching delay on my scope with that
01:26 katsmeow-afk the tip127 Vsat of 1.4v @ 6amp is like a fet at 0.23 ohms, the tip127 (or TIP42) is 100v and lots cheaper and tons easier to drive at 1Mhz
01:27 rue_mohr2 the irfz44 is .028R
01:28 katsmeow-afk yeas
01:28 rue_mohr2 only handles 60V
01:28 katsmeow-afk but driving at at 1Mhz takes a lot
01:28 katsmeow-afk mosfet vs bipolar is still tradeoffs
01:28 rue_mohr2 1900pF
01:28 tsmeow-afk sh
01:29 rue_mohr2 wonder what the reactance is of 2nf at 1Mhz
01:29 katsmeow-afk yeas, .0019 ufd, it's 1/5 of a power bypass cap!
01:30 katsmeow-afk i dunno, it's after 1am, i didn't finis dinner, my neck hurts, i am slowing way down
01:30 rue_mohr2 about 79 ohms
01:30 rue_mohr2 at 10V, thats 1.27W
01:31 katsmeow-afk that's 1.26 watts of gate drive
01:31 katsmeow-afk heh
01:31 rue_mohr2 :)
01:31 rue_mohr2 (I did lota rounding)
01:32 rue_mohr2 whats hfe on the 127?
01:32 tsmeow-afk looks slowly at
01:32 rue_mohr2 WHAAAT?
01:32 rue_mohr2 'm curious now...
01:32 katsmeow-afk 25C 2amp, 5k
01:33 rue_mohr2 how about 6A
01:33 rue_mohr2 prolly 2k atleast
01:33 katsmeow-afk yeas, at 25c
01:33 katsmeow-afk ~1.5k at -50c and +150c
01:33 rue_mohr2 so, I get 2.1mW drive loss for the bipolar
01:34 rue_mohr2 (assuming .7V, but it'd be 1.4 wouldn't it
01:34 katsmeow-afk yeas, which is why i'd use the mosfet if i needed really low Vsat at dc / 60hz , maybe audio, and could justify the cost
01:34 rue_mohr2 so, 4mw
01:34 tsmeow-afk
01:35 rue_mohr2 are, I can get 50 fet drivers for $25
01:35 katsmeow-afk good drivers?
01:35 rue_mohr2 yea, 2A gate drive
01:36 rue_mohr2 IR2101
01:36 rue_mohr2 oh, they are 270mA
01:37 katsmeow-afk when the very first CCD fifo chips came out, for delay lines, they came with driver chips, we blew up a dozen drivers a day, to clock the ccd at 5Mhz we had to push/pull *amps* into the clock pins
01:37 rue_mohr2 I have some REALLY GREAT bipolar motor driver chips, they are only good to 6V, but their CE sat is like .3V at like 1A
01:37 katsmeow-afk finally gave up on them they were just too hard to drive, they got hot and died after a while
01:38 tsmeow-afk
01:38 katsmeow-afk i forget the part #, but there's some nice to-92 very low Vsat bipolars for pwr switcing
01:38 rue_mohr2 so maybe todays driver parts purchse should be the tip 147 and tip142
01:39 katsmeow-afk at 1:23am, not gonna try to guess your best parts needs
01:39 rue_mohr2 oh right, tommorow
01:39 katsmeow-afk it's all up to you
01:39 rue_mohr2 I ahve to go to the hospital and get more copiers
01:39 rue_mohr2 gnight
01:40 katsmeow-afk 147 is a darlington and has a pretty good soa
01:40 katsmeow-afk ok,, gnites
01:40 rue_mohr2 http://olsonelectric.ca/wp-content/uploads/2012/09/watermark71.jpg
01:41 rue_mohr2 hah, its a image by my company,
01:41 rue_mohr2 thats where I work tommorow...
01:41 rue_mohr2 I'm fire alarm system guy :)
01:42 tsmeow-afk nods sl
01:42 katsmeow-afk looks like a very airy hospital,
01:43 katsmeow-afk do patients fall out of their rooms a lot?
01:43 katsmeow-afk drafty
01:43 rue_mohr2 its a condo
01:43 rue_mohr2 http://www.malaspinapm.ca/unit-406-at-the-watermark/
01:45 katsmeow-afk loks better finished,, shame the http://www.malaspinapm.ca/wp-content/uploads/2012/01/rocky_coast-1920x1080.jpg is hidden behind all that text
01:45 katsmeow-afk and that's there's a huge white square int he middle of the pic
01:46 tsmeow-afk wandes off to find what / where what's left of dinne
01:46 katsmeow-afk gnites
12:42 katsmeow-afk rue, example of staying on top of prices : http://www.ebay.com/itm/5A14N-Four-Channel-Amplifier-/200999683282 <<== *TWO* 5A14 , usually just one is $70, and these are in mint condition
12:44 katsmeow-afk another : http://www.ebay.com/itm/7A13-Differential-Comparator-/200999682538 <<== the owner-service manual *alone* goes for more than this package deal including the plugin, the plugin usually goes for more than $100 in this condition
12:46 katsmeow-afk sometimes, you buy the ower manual, they throw in the electronics for free, same as when i bought a plugin and they threw in the scope for free
12:49 katsmeow-afk there is a seller with "8GB" of ram listed for $35, problem is, he has no idea why it's listed as "8GB", and neither do i, because i can't find 8GB there, it has 144 sdram chips of 16megx4 (not 16megx8) per board (IBM AS-400 mainframe cards)
12:54 katsmeow-afk Target: 40M card accounts may be breached
12:56 katsmeow-afk Microsoft chairman Bill Gates has donated a cow as part of Reddit's Secret Santa gift exchange programme. He bought the $500 (�305) cow ...........
19:18 rue_house hah, chump chance gifts eh?
19:21 rue_house kat, can you finish this: a constant current source can easily be set up with a resistor and an LM______
19:26 Tom_itx sumpin sumpin sumpin
19:26 Tom_itx google that
19:27 Tom_itx i wish i could laser etch numbers on these tool holders
19:28 rue_house SILK SCREEN ETCHANT MASK
19:28 rue_house a blob of H2SO4 should be good for the actual etching
19:28 rue_house dunno where to get that tho, not like you can just walk out to the car and grab a few ml
19:28 Tom_itx battery acid?
19:29 rue_house do they use it in batteries??
19:29 Tom_itx i had 5 gal of sulfuric
19:29 Tom_itx i dunno
19:29 Tom_itx i got rid of it though
19:29 Tom_itx didn't feel like storing it
19:29 Tom_itx i do have some other stuff though for copper cleaning
19:29 Tom_itx dip it for a sec and it's clean
19:30 Tom_itx literally a sec or so
19:30 Tom_itx i forget what acid it is
21:41 Tom_itx looks better with the right cutter
21:46 Tom_itx http://tom-itx.dyndns.org:81/~webpage/cnc/pendant/engrave1.jpg
21:46 Tom_itx http://tom-itx.dyndns.org:81/~webpage/cnc/pendant/engrave2.jpg