no u
Posted by renesis at 20:52 | permalink | 0 comments
lordpil's blog
where is sculptor
what controller did he end up getting
Posted by renesis at 15:51 | permalink | 0 comments
welcome to the real world of stuff where everything is affected by everything else to various degrees at various times
at under 2A i would go ahead and assume its better than 100
they have a plot
shows an arc
Posted by renesis at 14:34 | permalink | 0 comments
yeah, clicked, its a darlington, im just guessing at 1000-3000 for beta, you could check
haha damn
MAX=15000
!!!@#$%^
i wonder if that is an error
Hfe MIN 500 @ 0.5A, 750 @ 2A, 100 @ 4A
see dont listen to me, check
Posted by renesis at 14:28 | permalink | 0 comments
and dont pick random resistors figure it out based on the drive voltage of the base resistor minus the Vbe drop of the darlington
Posted by renesis at 14:22 | permalink | 0 comments
welcome
"base_current = collector_current / beta" doesnt provide enough current to gaurantee saturation, prob wont saturate in all sorts of conditions
so do like Ib = ( Ic * 5 ) / beta
or Ib = Ic / (beta * 0.2)
same thing, thats why i said use 200 for a transistor with a beta of like 1000
Posted by renesis at 14:17 | permalink | 0 comments
beta is Hfe, its current amplification in a transistor
ratio of collector current to base current
so normal transistor has a beta of 150
feed it 1mA, it will provide 150mA
this is linear operation, using it as an amplifier
so you want it to saturate, low collector to emitter voltage
so the transistors dont eat power
so you need to drive it harder
say you want 1A from a transistor with a beta of 100
if you just give it 10mA, it probably wont fully saturate
like if the load tries to pulle 200mA, the transistor will get more resistive, drop more voltage, eat more power
so yeah, lower base resistor, give it more current
Posted by renesis at 14:11 | permalink | 0 comments
batteries?
current amplification, like linear operation, is 1000 to 3000
you dont want to run it linear, you want it to switch
so you want to feed it way more than its worst case linear operating current
Posted by renesis at 14:05 | permalink | 0 comments
1K is fine
if the darlingtons dont saturate, go down like 5% values at a time
like, they are dropping more than 0.7V
or so
1V at higher current
they have a beta of at least 1000
whats .8/200
!calc .8/200
how come we dont have some shit like that
timecop: srs wtf
okay so its like, .004
make sure you are giving the base more than 5mA
the beta is 1000
so use 200
this is low power shit or something?
Posted by renesis at 14:00 | permalink | 0 comments
have fry's desktop computer sort filters dores not include mem size
http://www.frys.com/product/5802083?site=sr:SEARCH:MAIN_RSLT_PG
wtf
Posted by renesis at 13:22 | permalink | 0 comments
o
im totally going to take my piles of electronic parts bins and give them to the assembly lady at work to sort
not even going to tell her how
Posted by renesis at 13:17 | permalink | 0 comments
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