Am I generating negative voltage here?

[demodb]

i'm a little in darkness here guys, maybe someone can shed some light into it. Looking at the picture, am i generating a negative voltage with respect to ground here?

 

[Element_115]

Re: negetive voltage

You are sucking all of the free electrons "OUT" of the Cap (for a short
period). So if electrons leave the top of the Cap it will have a
net positive potential.

 

[Kral]

Re: negetive voltage

demodb,
If the arrow denotes conventional current flow direction, then yes, the voltgae is negative.
Regards,
Kral

 

[mondunno]

negetive voltage

hi, dude,

wrt ground, yes.
its a neg ramp output (theoritically)across the capacitor.

 

[rob1012]

Re: negetive voltage

yes you are generating negative voltage wrt gnd

 

[demodb]

Re: negetive voltage

thx guys, i was a little worried whether this would work.

 

[user0]

Re: negetive voltage

Absolute voltage doesn't exist. Therefore you can put the GND sign anywhere you want in the circuit - all voltages lower than the GND potential are negative voltages.

For example look at the attached schematic. You can use the output as a (GND, +2,5V, +5V) supply, but you also can use as a symmetrical supply (-2,5V, GND, +2,5V).

 

[demodb]

Re: negetive voltage

how would you create such a current sink? Can i just use an NMOS with the source connected to a negative voltage, which is low enough to make sure that the NMOS does not go into triode if Vds becomes too low?