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`nico: yeah
panasonic makes a good one with a metal shaft
http://www.mouser.com/Search/ProductDetail.aspx?qs=%252bUYXD5bnyXp4Uf1MU7v3zw%3D%3D

Posted by renesis at 15:22 | permalink | 0 comments


now you fuck with R3 so it swings the base current from 0uA to 4uA
i would prob just use an opamp

Posted by renesis at 14:38 | permalink | 0 comments


so 9v-100mV-200mV is 8.7v across R1
870uA in saturation
divide that by 200
like 4uA
so you need to find a value for r$ that makes it act kind of linear
so lets cut 870uA in half, my guess is that gives us max output swing
so like 2uA
so 9v = Vbe (0.7v) is 8.3v, divide by 2uA
says use 4 Mohm
this shit will never work right

Posted by renesis at 14:33 | permalink | 0 comments


between R3 and C1 is AC voltage, no offset
between C1 and base is 0.7V, but the current is ac modulated
er
0.7v above R2
right
R4 turns the thing on
1k is too much
R1 begins to conduct, which lifts Q1 emitter because R2 is conducting
then R1 prob does into saturation because r$ too big
lets say its saturated at 0.2v
so voltage across R1 is (9v-0.2v)*(r2/(R1+R2))
so about 100mV

Posted by renesis at 14:28 | permalink | 0 comments


https://www.circuitlab.com/circuit/n7xb6j/screenshot/1024x768/
godkiller: that prob works ^
oh electret mic
ya
damn new circuit lab is capped at 10 components, theyre done with beta
prob like 20 to 200mV
its DC coupled to the mic

Posted by renesis at 14:23 | permalink | 0 comments


it can be used to amplify current, tho
collect voltage can wobble
emitter voltage is always 0.7v below the base voltage if the transistor is doing anything
sec

Posted by renesis at 14:13 | permalink | 0 comments


well, at 0.7v
under nothing conducts
so the voltage on both sides of the resistor is the same, below 0.7v
anove 0.7v, the base side of the resistor stays the same, but the other side increases in voltage
it conducts because of the voltage difference across the resistor
one side stays at 0.7v, the other you set the voltage to control the current
you need to try harder at electronics
now you broke my brain
if you put voltage directly on the collector, you need a resistor on the mitter
and then the voltage across the emitter resistor is always 0.7v lower, offset, from the input
its not an amp its a voltage follower, or buffer

Posted by renesis at 14:08 | permalink | 0 comments


at the emitter yeah
but base current will be insignificant, like 0.5% to 1%
above what
itll maybe saturate a bit more but generally once you saturate more base current is wasted
you cant
it clamps to 0.7v
no
below 0.7 it doesnt conduct, the transistor is off
you dont put voltage on the base
you put voltage on a resistor in series with base
the amount of voltage above the base to emitter voltage determines current through the resistor and into the base
multiple the current through the resistor by beta (Hfe) and you have collector current, maybe

Posted by renesis at 14:03 | permalink | 0 comments


nice new neighbor is bumping house
this means i can be loud and be like WHAT I WASNT LOUD GO ASK NEW NEIGHBOR

Posted by renesis at 12:15 | permalink | 0 comments


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