question about opamps and voltages

Started by gak, December 25, 2004, 03:03:01 PM

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gak

hi guys
i'm measuring 9 volts on each pad on a circuit connected to the power supply but the opamp vcc, where i got 0v... there is continuity between that pin and the ps.. is that possible?  :?:
thanks! merry christmas!

toneman

your question is kinda vague/confusing.
what opamp R U using?
what pin R supposed 2 have Vcc & gnd?
Look at a datasheet.
Also, what RU building?
Providing more info with your question would
help answer it.
:)
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gak

he
thanks for your answer..
i'm bulding a morley wah without all the buffers and cmos stuff.. i'm using a 741 opamp.. anyway, i think that's not important for my question.. i'm connecting the right pins to vcc and gnd (7 and 4), but i didn't succed because the pcb i was using had several mistakes... now i think i found and fixed em all, but i'm not getting voltage at vcc pin.. i'm getting 9v on every other point connected to ps... it seems there is continuity between these points and the vcc pin... so, before going crazy checking my pcb and connections once again... i wanted to know... a damaged opamp can cause a 0v reading even when connected to ps and getting 9v on every other pad?
my english is not so good, i hope you can understand me..  :oops:

Jason Stout

Quote... so, before going crazy checking my pcb and connections once again... i wanted to know... a damaged opamp can cause a 0v reading even when connected to ps and getting 9v on every other pad?
I'm not sure, but in your case the easy way to tell is to remove the opamp from the circuit, power up and then check the voltage at the vcc node.
Jason Stout

gak

uh, that was simple... i didn't think that..  :oops:

thanks a lot  :lol:

Jason Stout

Your welcome! But...It's only simple if you have the opamp socketed. (I socket about half the time)
Jason Stout