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I've got this homework about PSPice and op-amp. I need to make this triangular waveform and sawtooth(?) waveform of non-inverting op-amp circuit. I know the triangle one is 500us like the picture. But what about the sawtooth? The teacher told us to change TR and TF to 750us and 250us but it doesn't work. Am I missing something?

Oh and also, the triangle one supposed to start at 0V but mine starts at -4 volt instead. What can I do about it?

I'm new to PSPIce so please be kind ^^ Please do minor changes at the circuit.. (ex. changing the value of VPULSE) because that is what my teacher wants. Sorry for my bad english, and thank you for any help you can provide.

The waveforms have to look like these

I know I get the 500us right, because my teacher said so. I also know the meaning of all attributes like TD, TF etc. The question is

triangular result.

down here is the sawtooth thing circuit I've tried and also the result.

sawtooth circuit

sawtooh result

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  • \$\begingroup\$ What have you tried so far? If you can demonstrate this you might get better help. \$\endgroup\$
    – David
    Commented Sep 21, 2014 at 16:39
  • \$\begingroup\$ I've added two more pictures. I hope you check it. Thank you. \$\endgroup\$
    – Grace Firsta
    Commented Sep 22, 2014 at 0:50
  • \$\begingroup\$ @Grace_Firsta, are you sure that THIS is your task? I mean, just to produce the wave forms with a PSpice source? Are you sure that your prof does not expect from you to find an opamp-based circuit that produces these waveforms? \$\endgroup\$
    – LvW
    Commented Feb 20, 2015 at 13:56

1 Answer 1

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There might be a better way to do it (look at the VPWL and VPWL_ENH sources), but to keep this simple, try putting two sources in series, each producing half the waveform.

enter image description here

enter image description here

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  • \$\begingroup\$ Thank you for answering. I already tried your answer.. I put two VPULSE with the same numbers as yours but the result is just plain, straight lines. Any suggestions? \$\endgroup\$
    – Grace Firsta
    Commented Sep 22, 2014 at 0:39
  • \$\begingroup\$ Are you doing a transient simulation for an appropriate length of time (eg. 5ms)? \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Sep 22, 2014 at 3:36
  • \$\begingroup\$ Yes, I am. It is 10ms. \$\endgroup\$
    – Grace Firsta
    Commented Sep 22, 2014 at 3:58
  • \$\begingroup\$ Check the numbers carefully.. It should work.. Maybe you left out the 1ms delay time for the negative half. Other than that, I'm out of ideas. Post the actual images for this setup.. As you can see, it works perfectly for me. \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Sep 22, 2014 at 4:27
  • \$\begingroup\$ Ah.. you're right. I missed the 1ms delay. Thank you so much!! May I ask you what the 1ms is for? \$\endgroup\$
    – Grace Firsta
    Commented Sep 22, 2014 at 5:59

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