#garfield Logs
Mar 25 2015
#garfield Calendar
00:57 rue_bed typically they do a dc-dc conversion and then H bridge, or combine them into a transformer
00:58 rue_bed thats why i wanted the 60hz pwm generoator you helped me with
00:58 rue_bed that H bridge dosn't really have to be modified sine
08:32 katsmeow Sale ends in: 01d 17h 48m <<== "Old" 17h 48m ? is there a corresponding "new" 17h 48m ?
08:37 katsmeow i wanna sync the 60hz of the inverter to an external 60hz : keep accurate time, sync to powerline or generator for better switchover, etc
09:11 katsmeow “Man will not wait passively for millions of years for evolution to offer him a better brain.”
09:11 katsmeow -Corneliu Giurgea, 1972
09:15 rue_house easy enough to watch the zero crossings and bump the sample counter a little either way
09:18 katsmeow sample cuonter?
09:19 rue_house the counter that 'plays' the pwm rom
09:20 katsmeow ah ,, did you get the thing to play a sine wave?
09:20 rue_house yes, you dont remember?
09:20 rue_house it generated great pwm sine
09:20 rue_house (syncronous counters would have cleaned it up even more)
09:20 katsmeow i remember you were trying it
09:21 rue_house it worked
09:21 katsmeow "worked" as in 160 Vpeak sine?
09:21 rue_house I was gonna store 8 bit values in the rom and send them to a dac, you suggested I output pwm directly out of the rom, and it worked
09:21 rue_house I didn't put it thru a 120V driver
09:21 katsmeow why aren't you selling th ehell out of them?!
09:21 rue_house nobody would understand
09:22 katsmeow oh,, so it's 140 Vpeak sine?
09:22 rue_house anyhow, I should be able to convert any modified sine ups into a true sine
09:22 rue_house I tested it to the control circuit
09:22 rue_house its pwm
09:23 katsmeow cept for one thing: the power rating of the transformer , it'll limit the peak voltage to less than a true 120vac sine peak, i bet, just due to core saturation
09:23 rue_house I suppose, thinking about it, I could use 4 bits, and have all 4 fet controls pre-split out
09:23 rue_house its sine wave tho
09:23 rue_house the pwm is too fast for it, it'll filter it all out
09:23 katsmeow sine *out*, but the transformer sees the square wave pwm that makes the aine
09:24 katsmeow modified sine inverters don't output near 160v needed for real 120vac sine peaks
09:24 rue_house transformer is too busy filtering with its big iron core, the fet is the last thing to know about the pwm
09:25 rue_house http://ruemohr.org/~ircjunk/circuits/pwmsine/p1060737.jpg
09:26 rue_house ooh, I bit packed it
09:26 rue_house ah well, using a rom 8x larger than 64k is easy
09:27 tsmeow
09:27 katsmeow but iirc, you didn't scope the output of the transformer
09:27 rue_house the 7.864Mhz was the trickey bit
09:28 rue_house I didn't hook it to a transformer, didn't forsee any issues
09:28 katsmeow cept you cannot answer the question of the actual output
09:29 rue_house it was brought up that the fet drivers freq responce prolly falls short of the ~250khz pwm
09:29 rue_house then I should finish the project!
09:30 katsmeow yeas, before i blindly start a new one here
09:30 rue_house I was so thrilled with your 'integrate the pwm into the rom' that I stopped in awe
09:30 katsmeow oh
09:30 rue_house I need a better counter than the 393
09:33 katsmeow i wonder if you can use a megabyte flash, since those are serial i/o
09:34 rue_house I'd like to get a better counter
09:34 rue_house I prolly couln't clock the data fast enough, right now just the count rate is almost 8Mhz
09:35 katsmeow i figured flash chips were faster than 8Mhz
09:35 rue_house you need to clock in your commands at 8 bits each
09:35 rue_house oh, you means eeprom or flash?
09:36 katsmeow flash, thise lil sop-8 serial packages
09:36 rue_house ah
09:40 rue_house there must be an 8 bit binary counter
09:41 rue_house 40--?
09:41 katsmeow in a 40xx? i dunno
09:41 rue_house oh, 74HC590
09:41 katsmeow i use 74xx269 or 74xx569(?)
09:41 rue_house mmm 4040
09:42 rue_house its ripple tho
09:42 rue_house oooh wow, 590
09:42 katsmeow ripple = you haveto latch it
09:42 rue_house counter, storage reg, and output buffers
09:50 tsmeow looks peeved that pretending to be in London means the weather in the usa is displayed in centig
10:02 katsmeow shame it isn't a cnt up and down
10:03 katsmeow like: count up from zero to peak, then reverse count from peak down to zero, then reverse count up to peak, then reverse count down to zero ,, you need only 1/4 the memory
10:06 katsmeow 74269 , 74579 , 74779 ,
10:18 katsmeow well, can't get memory that small anymore anyhow
19:23 katsmeow too smokey utside to work
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19:28 katsmeow d host name `www.littleboxchallenge.com'.
19:28 katsmeow in any case, it does not forking work
19:29 katsmeow rosewill.com's page of authorised dealers doesn';t deal in Rosewill stuff
19:29 katsmeow they say they keep stock of stuff, i can find only 2 of the item i want, worldwide
19:29 katsmeow in any case, it does not forking work
19:30 katsmeow abc evening news today was a repeat of yesterday's news ,,, "news" no longer forking works
19:34 katsmeow "The airline has not disclosed the identities of the pilots, except to say that the captain was a 10-year veteran with more than 6,000 hours of flying time in A320s." -- what a shame he was locked out of the cockpit , instead of flying the aircraft
19:35 katsmeow Cabin depressurization, one of the possibilities speculated about on Wednesday, has occurred before, perhaps most notably in the crash of a Cypriot passenger plane in 2005 that killed all 121 people on board as it approached Athens.
19:35 katsmeow In that case, Helios Airways Flight 522, a slow loss of pressure rendered both pilots and all the passengers on the Boeing 737 jet unconscious for more than three-quarters of an hour before the aircraft ran out of fuel and slammed into a wooded gorge near the Greek capital.
19:36 katsmeow which has nothing to do with the crash yesterday, but it makes for drama
19:37 katsmeow "This official said that the lack of communication suggested that the pilots might have been incapacitated as a result of an onboard failure such as a loss of cabin pressure, which could have deprived the crew members of oxygen."
19:38 katsmeow EXCEPT THAt :
19:38 katsmeow “The guy outside is knocking lightly on the door and there is no answer,” the investigator said. “And then he hits the door stronger and no answer. There is never an answer.” He said, “You can hear he is trying to smash the door down.”
19:40 katsmeow scaling in a pipe : http://cdn.phys.org/newman/gfx/news/2014/1-newsurfacetr.jpg
19:42 katsmeow the guy outside, trying to bash the door down to get into the cockpit, is the pilot
22:21 tsmeow-afk had totally forgotten that ELP did "Lucky
22:49 Tom_itx yup
22:53 katsmeow-afk five 170Mhz ramdacs for 99 cents : http://www.ebay.com/itm/5-TI-TLC34076-ENHANCED-RAMDAC-PALETTE-256-16M-24-BIT-170MHz-5V-PLCC-84-SMD-SMT/221575356114
22:53 katsmeow-afk <<== glad the serious weather bypassed Tom
23:38 tsmeow-afk puts Brenda Lee on pause to go check the state of the smog out