#garfield Logs
Feb 15 2020
#garfield Calendar
03:15 AM rue_shop1: hmmm, so my 74hc14 oscillaors aren't behaving
03:20 AM rue_shop1: polprog, its the same as a 555 with the resistor tied back to pin 3
03:20 AM rue_shop1: polprog, nice
03:36 AM rue_mohr: https://twitter.com/Workshopshed/status/1228596465167151104/photo/1
04:12 AM Tom_L: morning
04:20 AM rue_mohr: no, I'm done for the night
04:20 AM rue_mohr: my eyes are snapping shut
04:21 AM rue_mohr: its only 2am :(
04:58 AM polprog: at 2 am today i built a super slow blinker with that hct14 oscillator
04:58 AM polprog: blue led was still visible even when lit thru a 1 meg resistor at 5 V
04:59 AM polprog: 100uF and 100Kohm made a nice 9 second period blinker, led connected via a capacitor flashed nicely
05:00 AM polprog: overall i could measure the circuit on the uA range, it barely toom more than 1000 uA
05:00 AM polprog: i think it was blinking for a good 30 mins when powered off a 12V charged 47'000uF cap
05:03 AM * polprog looks around for a ttl counter
11:43 AM polprog: hmm, none of these, ill have to buy some
11:43 AM polprog: but i made a beeping circuit... it just beeps
12:32 PM rue_bed: polprog, super slow?
12:33 PM rue_bed: wow
12:33 PM rue_bed: :)
12:51 PM polprog: i need some low power 74 series ics
12:51 PM polprog: :) make an eternal blinker
01:45 PM rue_mohr: heh
01:45 PM rue_mohr: w/joule thief?
02:16 PM polprog: nah, maybe with a supercap
02:17 PM polprog: i started playing with these oscillators to make a better boost converter for the VFDs
02:18 PM polprog: i dont know what to regulate for the closed loop control. The old design used to regulate the duty cycle for the switching fet, the new design can regulate frequency using a control voltage
02:19 PM polprog: im also looking at this network card isolator..
02:20 PM polprog: its got two pairs of the same windings, maybe if i ran "primaries" in paralell and "secondaries" in series i could get a voltage boost
02:28 PM rue_mohr: did you see the stuff I put on google drive?
02:37 PM rue_mohr: http://retro.hansotten.nl/wp-content/uploads/2017/05/osi300circuit-1024x775.jpg
03:18 PM polprog: what google drive?
03:18 PM polprog: o, 6502
03:34 PM polprog: bloddy hell
03:34 PM polprog: the hct14 is not sitting right in the breadboard causing lots of nastiness but mosty frequency instability
03:42 PM polprog: rue_bed:
04:05 PM polprog: these dual diodes scavenged from the dead psu can be used as varicaps easily!
04:13 PM polprog: lt6221 <3
04:36 PM polprog: rue_bed: https://polprog.net/rozne1/ircjunk/better_vco.png
04:44 PM rue_mohr: uh 1 in
04:45 PM rue_mohr: https://drive.google.com/drive/folders/1N4jzNWqBqXeMwXQbvy5CtiEEdhUEzfOY
04:46 PM rue_mohr: polprog, you have to ground all the unused 14 inputs
04:46 PM rue_mohr: otherwise you get horendous noise
04:55 PM polprog: yeah i know
04:57 PM polprog: wow thanks :D
04:57 PM polprog: that drive liink
05:05 PM polprog: replaced the vco pic with one that has the grounds connected :v
05:09 PM rue_mohr: oh nice
05:17 PM polprog: i see your VFD driver
05:17 PM polprog: its nice
05:17 PM polprog: im trying to mak a 5v only one
05:18 PM rue_mohr: I have that oscillator section too :)
05:18 PM rue_mohr: I didn't do that kinda diode as a varicap tho
05:18 PM polprog: yeah, im lurking trhu it
05:19 PM polprog: oh. im happy i could surprise you :P
05:19 PM polprog: im sure you have a ton of these diodes
05:19 PM polprog: i took these from an atx psu
05:19 PM rue_mohr: yup!
05:19 PM polprog: this one came with 3 identical ones
05:19 PM polprog: which is a nice surprise
05:19 PM rue_mohr: I did play with an osc that use diodes for varicaps, I dont recall what doide came out with the most range
05:20 PM polprog: https://drive.google.com/file/d/1WBC0Dj1_dftAXEvHVqUgstVinO1UiUsK/view
05:20 PM polprog: measuring the speed of light? :v
05:20 PM rue_mohr: 500kHz!!!!
05:20 PM rue_mohr: thats amazingly fast for those optos
05:21 PM rue_mohr: see the normal one with the pullup, only good to 15kHz
05:21 PM polprog: oh neat
05:22 PM polprog: i have some optos i need to test
05:22 PM rue_mohr: p.s., carefull with those oscillators, often they will not start at any setting,
05:22 PM polprog: yeah i noticed mine didnt start for R > 100k
05:22 PM rue_mohr: but once started will run to it
05:22 PM rue_mohr: you have a strange 1 :)
05:22 PM polprog: at 100k it had a very limited control voltage range
05:23 PM rue_mohr: my filter profiler has the hardware to be able to do a voltage sweep on a circuit and plot freq, I might modify it for that for a bit
05:23 PM polprog: hmm. i could use a curve tracer
05:23 PM polprog: i need to set up a fila like you have
05:23 PM polprog: these little papers have been multiplying
05:23 PM polprog: i need to organize them
05:24 PM rue_mohr: I just posted that cause some people on twitter were asking
05:24 PM rue_mohr: the binder has taken on almost 1/4" of circuits this month
05:24 PM polprog: that as in the whole binder?
05:24 PM rue_mohr: was, its thicker now
05:24 PM polprog: hmm my hct14 as ring osc will do 44MHz
05:24 PM rue_mohr: and I created an "Isolators" section
05:25 PM rue_mohr: you can play with the freq in a ring by adjusting vcc too
05:25 PM polprog: i need to try 2n7000 ring osc
05:25 PM rue_mohr: see the nand based on where I squeezed the chips vcc range with a fet
05:25 PM polprog: yeah
05:26 PM rue_mohr: lots of the conditioning I was adding was to try to remove ring that the circuit didn't really have
05:27 PM rue_mohr: so was 2:1 the best range from that vco?
05:27 PM rue_mohr: I got a bit more than 10:1 from one
05:27 PM polprog: let me se
05:27 PM polprog: there are some measurements on the picture
05:27 PM polprog: hmm
05:27 PM rue_mohr: hi zhanx
05:27 PM polprog: actually let me check again
05:28 PM rue_mohr: it looks like you had ~50kHz ~25kHz
05:29 PM polprog: thats at 51k
05:29 PM polprog: im putting in a 10k now
05:29 PM rue_mohr: the ratio (~2:1) might be the same
05:29 PM polprog: thats what im trying to check
05:30 PM rue_mohr: I eneded needing about 20:1, so I was trying to do multiple CDS RC stages
05:30 PM polprog: yea. 140-302khz
05:30 PM rue_mohr: 10:1 is HARD
05:31 PM rue_mohr: I was making a bench signal gen, I wanted to have 10:1 on a knob, with range select switches
05:32 PM rue_mohr: I ended up using a dds module
05:32 PM polprog: hmm. very nonlinear with 1k in
05:32 PM rue_mohr: partly because the vcos' that I COULD get up to 20Mhz, were not stable
05:32 PM rue_mohr: I could literally watch the freq rise as I stepped closer to the circuit
05:33 PM polprog: 1790 - 3310 but the maximum freq is at 2/3 voltage then it drops to 2582
05:33 PM polprog: haha
05:33 PM rue_mohr: still about 2:1
05:33 PM polprog: yeah
05:33 PM rue_mohr: still cool!
05:33 PM polprog: maybe other "varicaps" would behave better
05:33 PM rue_mohr: I tested a bunch of diodes
05:33 PM polprog: i have a big beefy sb3060 here
05:34 PM rue_mohr: I dont really know where the data is for them...
05:34 PM rue_mohr: the answer surprised me
05:34 PM rue_mohr: I tried different transistors as varicaps too
05:36 PM polprog: heh this one barely starts at 10kohm
05:36 PM rue_mohr: I think there were TO-92s that did REALLY well
05:36 PM rue_mohr: like 5:1
05:36 PM rue_mohr: I should try to find those notes
05:36 PM rue_mohr: not *now* tho
05:37 PM polprog: similar, 1.4MHZ - 2.8MHz
05:37 PM polprog: very nonlinear at 1k
05:37 PM polprog: duty cycle varies a lot
05:38 PM rue_mohr: /2 fixes that
05:38 PM rue_mohr: do you see my 74hc14 based flipflop in there?
05:38 PM polprog: yeah, i dont have any counte
05:38 PM rue_mohr: then you dont need another chip
05:38 PM polprog: i do actually, but a bcd one. id have to wire a reset pin
05:39 PM rue_mohr: its under power supplies, cause its for doing pushpull driving
05:39 PM polprog: no, let me look
05:39 PM rue_mohr: I think
05:39 PM polprog: https://drive.google.com/file/d/1OFTopgV05X5GPyiOa4Dz-wpNaKuMAv0d/view
05:40 PM polprog: theres a note to see the other schem, i cant find it
05:40 PM polprog: i like it. its like TAOE for hackers
05:42 PM rue_shop1: ok yea, I did it to reduce the parts count on that one
05:43 PM rue_shop1: hmm its in that section here
05:45 PM rue_shop1: https://drive.google.com/drive/folders/1N4jzNWqBqXeMwXQbvy5CtiEEdhUEzfOY
05:45 PM rue_shop1: that on the right is a toggle flipflop
05:46 PM polprog: which section
05:46 PM rue_shop1: the right
05:46 PM rue_shop1: with the two gates
05:46 PM polprog: i cant see it
05:47 PM rue_shop1: ...
05:47 PM rue_shop1: arg
05:47 PM rue_shop1: google drive is hard to use
05:48 PM rue_shop1: 1140998
05:48 PM polprog: 50% duty complimentary spms osc?
05:48 PM rue_shop1: 1140999 is a discrete version
05:49 PM polprog: i see.
05:51 PM rue_shop1: I did the 74hc14 version so that I could have a garunteed 50% osc with complimentrary outputs for power supplies
05:52 PM rue_shop1: I wonder if I should break that folder down into subfolders
05:52 PM rue_shop1: its hard to use on my computers, it eats the entire browser
05:53 PM polprog: why not use ircjunk
05:53 PM rue_shop1: full size images
05:53 PM rue_shop1: I'm trying to keep ircjunk volumetrically trim as its donated space
05:54 PM polprog: ah
05:54 PM rue_shop1: this was just a huge web glob
05:54 PM rue_shop1: at 15G it could be much larger tooo
05:54 PM polprog: yeah, i resize mine down to 800x600 even
05:54 PM rue_shop1: yea, and its a reasonable thing to do!
05:58 PM polprog: ok. done for today
05:58 PM polprog: ill put the papers in a file, and hit the bed
05:58 PM polprog: 00:51
05:59 PM polprog: i have some ULA6102 ICs to play with later. dual diff amps
06:00 PM rue_shop1: with diff outputs?
06:00 PM polprog: didnt read
06:00 PM polprog: https://polprog.net/rozne1/ircjunk/ula6102.pdf
06:00 PM polprog: just looked thru
06:01 PM polprog: there are no schems of ula6102 in particuar but there are two others
06:01 PM polprog: maybe it will be in the parts book, if so ill scan it
06:03 PM rue_mohr: oh, its transistors
06:03 PM rue_mohr: heh, I guess that makes it whatever you want
06:03 PM polprog: :p
06:27 PM polprog: [note to self page 251 in the blue book]
06:29 PM polprog: drawing page 409
06:29 PM polprog: like ul1102
06:29 PM polprog: okay
06:35 PM rue_mohr: ?
06:36 PM polprog: the odf didnt show the schematic for 6102 but the databook shows its the same as 1102
06:36 PM polprog: pdf*
06:37 PM polprog: i have a databook for old polish and eastern bloc ICs ever made
06:37 PM polprog: if you need a cyryllic chargen, let me know lol
06:37 PM Tom_L: .
06:37 PM polprog: hello Tom
06:39 PM Tom_L: hi
06:40 PM rue_mohr: Tom_L, where is your fpga at?
06:40 PM Tom_L: in the drawer
06:40 PM rue_mohr: I took a run and I dont know where you were
06:40 PM rue_mohr: oh :/
06:40 PM rue_mohr: what did you do last?
06:40 PM Tom_L: i don't remember, it's been a long day
06:41 PM rue_mohr: you were waiting for me to come up with the encoder thing
06:41 PM rue_mohr: and I had to make a bidir counter
06:41 PM rue_mohr: which I have now
06:41 PM Tom_L: i did the 7seg with overflow led indicators
06:41 PM Tom_L: i did the encoder counter
06:41 PM rue_mohr: ah
06:41 PM rue_mohr: did you do pwm?
06:41 PM Tom_L: maybe
06:42 PM Tom_L: led pwm possibly
06:42 PM rue_mohr: then were close
06:42 PM rue_mohr: we just need a communication interface
06:42 PM Tom_L: oh i did the keyboard sample
06:42 PM polprog: what are you making?
06:42 PM Tom_L: showing scancodes
06:42 PM Tom_L: a mess right now
06:42 PM Tom_L: eating tacos
06:43 PM rue_mohr: apparently were circling the drain of an fpga servo
06:45 PM Tom_L: think how many servos you could control with one
06:45 PM rue_mohr: ;)
06:46 PM rue_mohr: arg, its only 4:30 and I'm falling asleep
06:46 PM polprog: never run out of pins again :)
06:46 PM rue_mohr: I need to be awake so I can go make the new coil winder and put some transformers togethor
06:46 PM Tom_L: cnc coil winder
06:47 PM rue_mohr: polprog, check out the TLC5940
06:47 PM polprog: i think i have one on a semi failed breakout
06:47 PM polprog: yep
06:47 PM rue_mohr: oh :/
06:48 PM polprog: shit.. out of toner
06:49 PM Tom_L: wonder what they use on led signs
06:49 PM polprog: not these iirc
06:49 PM polprog: more things like the uln2003
06:49 PM polprog: yu have to scan them yourself
06:49 PM polprog: you*
06:50 PM rue_mohr: I seem to have the only zvs heater board that nobody has ever taken a picutre of in use
06:55 PM polprog: oh, neat.. i seem to have two horizontal scan generators.. they take video in and spit hscan signals
06:55 PM rue_mohr: well it puts my injection moulder project back on the table anyhow
06:55 PM rue_mohr: k
07:23 PM polprog: rue, i managed to get 3.2:1 frequency range
07:24 PM polprog: the varicap seems to be best biased at around 15V... then the frequency gets lower again as the voltage increases
07:25 PM polprog: further over that 15V. at 25V its back to whats at 1.5V
07:35 PM polprog: nighters
08:05 PM X704 is now known as tiwake
08:11 PM rue_shop1: good news
08:11 PM rue_shop1: the cat just pointed for me
08:12 PM rue_shop1: looks like the mouse went the opposite way than what I'd expcted