Phase Control of SCR

[Tanya Sharma]

The project was taken from this website
**broken link removed**

I'm trying to simulate the circuit. The only changes i made is that the i'm directly using 9v 50hz ac supply.
I'm not sure why my rectified output is not reaching 0v. According to the description of the project it should. I'm attaching the proteus simulation file and i used the code from the website.

 

[barry]

What do you mean "output is not reaching 0V"? What IS it reaching? Maybe 2V (like you'd expect)?

 

[Tanya Sharma]

I should get rectified half wave that should be from 0 to 4.5 v. But my wave does not touch the 0v axis.

 

[barry]

Why "should" your wave go to zero? Are you measuring at the anode of the SCR? Are you forgetting that the SCR has a forward voltage drop?

 

[milan.rajik]

If you are simulating in Proteus and using its oscilloscope then it has a AC and DC buttons for each channel and if you are measuring DC click DC else click AC button. Proteus file attached.

- - - Updated - - -

See the image. The graphs are correct. You are getting 2V because the 1uF capacitor is quickly charging and discharging to 2V. See the graph starts from 0V. Also applies to other graphs.