clarification on basic not gate

[Bhuvanesh Nick]

i am new to electronics

in above not gate circuit diagram how i am getting hight output for no input and no output for high input


doubt(even if its hight input..i have collector voltage am i right)

 

[Pradeepbp]

when input is zero, your transistor is off. there will be no current flow between collector and emitter. so CE junction acts as open, so full voltage appears across CE junction and you get output as high!
when input is high, the CE junction acts as short, so it appears as output is connected to ground. so output voltage will be 0.

 

[keith1200rs]

You need to use an NPN transistor not PNP.

Keith

 

[Bhuvanesh Nick]

why is that so ..wy dont i use pnp

 

[keith1200rs]

I am assuming you want to use an input voltage between 0V and 5V? If so, you will never turn on the PNP the way you have drawn it. The base of a PNP needs to be more negative than the emitter to turn it on. You could use a PNP with the emitter to +5V and the resistor load to 0V.

Keith