Author Topic: PNP Transistor Circuit - Switch or Amplifier?  (Read 2830 times)

0 Members and 1 Guest are viewing this topic.

Offline sunny1Topic starter

  • Newbie
  • Posts: 4
PNP Transistor Circuit - Switch or Amplifier?
« on: February 17, 2013, 02:34:58 pm »
I am unable to figure out here if the the PNP transistor in this circuit acts as switch or amplifier? Can anyone please help me figure out how the output voltage Vout looks like in this circuit? Thanks!
 

Offline mark-r

  • Contributor
  • Posts: 32
  • Country: gb
Re: PNP Transistor Circuit - Switch or Amplifier?
« Reply #1 on: February 17, 2013, 03:16:20 pm »
Looks a bit like an integrator, although there is some detail missing from the circuit. If the base is held 10V below the +10V rail, then the emitter will be held at ~9.4V below the 10V rail (provided enough current can flow out of the base from the 10V source). So, there will be a constant ~9.6mA current flowing into the emitter, and so about the same from the collector. Assuming the capacitor is discharged, the voltage will rise linearly from -10V towards 0V.
 

Offline jeroen74

  • Frequent Contributor
  • **
  • Posts: 396
  • Country: nl
Re: PNP Transistor Circuit - Switch or Amplifier?
« Reply #2 on: February 17, 2013, 03:34:25 pm »
Get LTSpice and simulate it. Be sure to turn on the 'skip initial operation point solution' option. The result is as mark-r says.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf