k4kfhHey guys - I'm trying to build a small single-transistor audio amp and I built a typical common emitter amp, and it seems to work, except that when I connect a speaker the voltage collapses as though it can't supply enough current. Why?
BuizelBecause you didn't supply a drawing or photo of your circuit.
intranicka wild Buizel has appeared!
k4kfhI copied this: http://www.falstad.com/circuit/e-ceamp.html
k4kfhExcept I used 12V supply instead of 20V supply
k4kfhWhen I just connect my scope to the output everything works as expected and I get a nice clean sine wave, but when I connect a little piezo speaker the voltage drops to the millivolts
intranickShadyman: yo
intranickShadyman: somebody left a band i listen to :/
AlphaEchok4kfh: What's the impedance of the piezo speaker? I'm guessing it's low....
AlphaEchoThat circuit has 1k emitter degeneration, so if your output impedance is signficiantly larger than that 1k, it's going to 'drown out' the amplifier's ability to output current
k4kfhI would guess the speaker's impedance is in the single digits so is the amp just fundamentally unable to supply that much current?
k4kfhWhat's strange is connecting the speaker directly to my cheap function generator works fine, so it can't be drawing THAT much current.
BuizelFunction generators have output stages that are designed to sink or source a reasonable amount of current
BuizelYou can do the math yourself to figure out exactly what your speaker would draw
intranickBuizel: buizels like water dont they
Buizelyeah :3 buizels are for waters :3!
intranickACTION is bored
Shadymanintranick: rip
Shadymanintranick: you preorder the wooden box set?
prpplague* intranick is bored
intranicki think im going to pass on it this time :(
prpplagueare you an MDF or ply wood bored?
intranickprpplague: thats board
intranickShadyman: mostly for moola reasons
prpplagueintranick: meh, same difference
Shadymanbut what do cows have to do with it?
intranickShadyman: but they wont be the same without casey grillo
intranickthen again, i was fretting with khan's departure
intranickbut i actually like tommy more
intranickkhan was amazing no doubts there, but Tommy brought them to a whole new level
prpplagueintranick: who/what are you discussing?
intranickprpplague: the band kamelot
WereWoofACTION checks in..
sgrace_wrkHappy Thursday.
sgrace_wrkThirsty Thursday
polprogFat thursday
gchristensensure enough!
WereWoof 27 Merlin 1D engines alight and PUSHHHHHHHHHHHHHING
sgrace_wrkIf only a frog was jumping in that shot.
learathWereWoof: that photo is *amazing*
learathsgrace_wrk: so you want to see https://www.youtube.com/watch?v=M93M6fnWHok with an elephant?
learathI wonder if that would impact thrust
sgrace_wrkMore that
learathhah that's crazy.
sgrace_wrkThe Internet blew up when that image showed up.
sgrace_wrkPETA, of course, was pissed for no reason.
learathWell, was the frog not eaten?
sgrace_wrkPeople were concerned that it might have died due to the heat of the rocket.
sgrace_wrkNo one knows... It's Florida.
sgrace_wrkAs soon as the area calmed down, it might have gotten eaten.
sgrace_wrkDid you know, toads are known to eat each other?
sgrace_wrkThey take "opportunistic cannibalism" quite seriously.
sgrace_wrkI think it was a NatGeo show I saw a while ago, where they were talking about toads, and a toad choked to death because it tried to eat another toad (a bit too big for it) what that toad was eating a smaller one.
learaththat is crazy
Snert__show them the movie of Edison juicing up a full grown elephant.
sgrace_wrkSnert__: Edison gave elephants PEDs!?!?
Snert__He wanted to prove that AC current is dangerous compared to DC.
Snert__he lost, of course.
Snert__the westinghouse vs. edison conflict back in The Dark Ages.
Snert__even then, the public backlash from electrocuting the elephant killed him.
gchristensenit was the right thing anyway
learaththe right thing at the time.
gchristensenI mean public backlash over electrocuting an elephant
Snert__poor Topsy.
s73v3ri remember hearing that, up until very recently, there were still some places in the greater NYC area that were wired for DC instead of AC
sgrace_wrkSnert__: I know about the Edison thing... Just tried to make a joke about enhancement drugs and "juicing."
Cmdr_dataheh .. if you would connect a device with a normal transformer to DC not much would happen .. but i guess a device with a switched PSU would work
Cmdr_datalooks like the air force blew up the spacex rocket that landed intact on water to safe it http://www.americaspace.com/2018/02/08/air-force-strike-takes-out-spacexs-floating-govsat-booster/
sgrace_wrkSafe it?
learathsgrace_wrk: make it not explode
learaththat's a shame.
Cmdr_datawell .. if the electronics get wet they might not be able to get the high pressure of the helium vessels
sgrace_wrkIs this tongue-in-cheek?
OttomiteThe airfoce has cataloged the tesla as well.
sgrace_wrkOh man...
sgrace_wrkThis stock market correction stuff...
sgrace_wrkIt's funny, yet sad.
learath..... what the hell am I watching?
sgrace_wrkExactly, it's awesome.
sgrace_wrkAWOLNATION made a music pack to the game Dota 2.
sgrace_wrkThey hired a guy who uses Valve Software's Source Film Maker to make a music video for them.
learathvery well done
sgrace_wrkThis guy won an annual contest 3 times in a row for the Source Film Maker.
intranickACTION yawns