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theres a circuit where you fuck with mirror bias with a pot and it adjusts gain
like, hot rod 60dB mic pre shit for couple dollars in part
jero32: look up Vbe multiplier current sinks
you can get accurate absolute current to feed the mirror regardless of rail voltages
wait no thats for AB bias, its the Vbe reference is used as a current sink, and you just connect collector to whatever
its basically your first circuit with a resistor instead of a diode
anyway, night

Posted by renesis at 09:40 | permalink | 0 comments

yeah that matched part is somewhat important if this isnt a 20% fuckit thing
other hacker still does this
he gets pissed because digikey stops stocking these power transistors
and he orders them from ebay and its like unmatched leftovers
yeah
or they will be TO92 touching, maybe glued
yeah it doesnt need to be that ideal
yeah those little multi to92 sinks are cute
jero32: typically this is how you drive long tail pair diff input
if you can spare the extra $.25
then on the bottom of the long tail pair, you have a resistor or a current sink
and that sets mirror current
often no resistors, NPN long tail pair collectors to PNP mirror collectors, or whatever

Posted by renesis at 09:35 | permalink | 0 comments

theres not
the base current just does its thing
youre basically setting collector current
and that current shows up at the other collector
theres no feedback really, but it works well enough
?
it goes into both
its like two resistors to the emitter
?
its magic
the collector doesnt really reference the base
everything references the emitter
i mean
honestly i dont think that is 100% correct
like, Vce can be 0.1V
Vbe is basically always 0.7V
yes
its operating linear

Posted by renesis at 09:30 | permalink | 0 comments

dude use the text tool
the right one is getting same base current because theyve basically clamped each other
and because the loading is close enough, the currents can match
collector current is the same because Hfe and base current are same?
blackmoon: cool
hourly rental car is so rad
like, i just leave that shit like, fuck you and you maintenance and you gas (zipcar pays for gas)
there is voltage across the resistor, and what isnt used by the base goes into the collector
and i think the collector current somehow stabilizes the base impedance
i have this class next semester
?
the collector is 0.7v above the emitter
if you have a steady voltage rail, you can use that voltage reference to set current

Posted by renesis at 09:25 | permalink | 0 comments

so thats a known voltage, maybe
like, if you have pretty stiff rails, and theyre large enough, you can just use a resistor and the current should be close to what you want
jero32: i think because the transistor is being run linear and the base resistor shows up as an impedance
sorry, not base resistor, by the base emitter PN junction
like, basically i would look this up in my electronics textbook
theres that fucked up section with all the other parameters besides Hfe
jero32: left one?

Posted by renesis at 09:20 | permalink | 0 comments

its assumes Ib will split evenly, and Hfe is matches, and the Ib is insignifcant compared to load current
and then shit just works
i mean left and right are doing the same thing, it just happens to take the base current from the left side
like, where the current is coming from isnt really important, just that its from the right voltage
the current splitting equally, because matched Vbe characteristics, and gain being equal, because matched Hfe, the current across both loads will be the same
realistically, its going to be as close as youre willing to spend on transistors, or time spent matching them
right thats the bias one

Posted by renesis at 09:15 | permalink | 0 comments

i think load needs to bias the transistor
because load is prob set to saturate
so a low current but it sets up the BJT voltages for normal operation
like, load resistor is set so it cant be Hfe*Ib
i dont really get it
maybe there is some sort of negative feedback element with the saturation voltage and Vbe
BJT current mirror with identical parts is whats typical, which prob means that circuit doesnt work great
this is trying to use diodes as resistors with magic curves, instead of check valves

Posted by renesis at 09:10 | permalink | 0 comments

jero32: see the schematics after?
with two BJT connected at the base?
thats a current mirror, like i seen that in prob 100 audio circuits
elliot sound prob has an article section about it
sure i guess, but i dont know how you decide how much current flows into the base
i think its load dependent?
fuck im not even sure base current happens if diode Vf is too low
assuming the diode’s PN junction and the transistor’s base-emitter junction are well-matched to each other.
yeah theyre basically explaining, fuck this circuit
itd be nice if they just came out and said it
i dont even trust running two of the same diodes like that

Posted by renesis at 09:05 | permalink | 0 comments

maybe
like, i should go do responsible things but if its something short i can use you to procrastinate
hmm what
i guess they are using a diode to clamp out Vbe
holy fuck
are they using electron flow?
they are using electron flow
even text books dont use electron flow unless you special order them, i think the mil uses it because fuck them

Posted by renesis at 09:00 | permalink | 0 comments

yeah i saw going to saw, looks like a goofy saw icon
wago stuff is neat

Posted by renesis at 06:34 | permalink | 0 comments

i mean, i like hanging out with her, and she only calls when she wants sex more than risking a serious argument with me
and she cares, even if she gets that confused with trying to take advantage for me
and she prob has couple hundred dollars in groceries shipped to my place
pretty sure she is geniunely confused about what i complain about until she has had some time to think about it
like, she comes from very big, caring, religous family, were lying to save relationships is just normal
i come from a family catastrophe where my coping solution was brutal honesty

Posted by renesis at 06:23 | permalink | 0 comments

jero32: anyway her figuring out how to keep my hard was basically the fun part
jero it just means i dont have to talk to her when i make any decisions
or for years at a time
if you can call talking on and off with several years long gaps, dating, sure
while we dated other people
and she had a couple full blown relationships

Posted by renesis at 06:18 | permalink | 0 comments

heh @ exgf doing custom dildo before kits
wtf is the spiral/saw thing on the breaker module?
jero32: well she didnt think it all the way through, and jumped off and just gooped on latex
i did not expect. anyway, pubes got all stuck so i had to like cut them all off, like fuck we could have poked a hole in a ziplock or something
she doesnt get to plan next project
pretty sure weve fucked more since weve broken up than since we were dating
i should text her, its been almost year since i told her to go away
*than when we were dating

Posted by renesis at 06:13 | permalink | 0 comments

how are custom fit condoms not a thing
like earplugs
prob no one wants to be liable
i mean like, custom mold
kind of like make your own dildo
sure you would go to a place
thats how i feel about the ear plugs and ear buds but theyre still a thing
that sounds useful
smallest tips usually work for me

Posted by renesis at 06:08 | permalink | 0 comments

yeah like kids toys
like, fisher price car
i think they injection mold a thing and blow it up into a bigass mold
bigass blow mold prob doesnt have to be a solid block of steel or aluminum
like, they have flash seams but theyre squished
i think for simple stuff they do
tubaman-: ha weird, never thought about that

Posted by renesis at 06:03 | permalink | 0 comments

this is the place to go if you want to make lots of things

Posted by renesis at 05:58 | permalink | 0 comments

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