How can I do a 10 khz square wave with LtSpice ?

[tessier]

Originally Posted by jcx

for symmetry you need to set Ton = (1/2)*(1/f) - t_rise

use curly brackets, .param to save typing

Hi

I've try your param but it was not work ok.

Can you show me a capture image of the LtSpice Fonctions window showing the pulse parameters.

Thanx

Paul

[jcx]

clik on the attachment thumbnail?

the line:

.param f = 31k, t_edge=1u

has to be entered in the <.op> tool pop up window (far right on toolbar)

the line:

PULSE(-1 1 0 {t_edge} {t_edge} {1/2/f-t_edge} {1/f})

is the "value" entry for the Vsource, usually entered in the dialog window but can be pasted in the pop up box when rt clking on the value

[edit: paste the line in a Vsouce "Value", then rt cik Vsource body, you will see filled in parameters in window]

add new named params to control additional sources, you can have f1 = 10k, f2 = 31k on the same schematic with the Vsources each using the appropriate parameter name

[tessier]

Hi

I was meaning the LtSpice Fonctions window like the image I show here.

Thanx

Paul

[sawreyrw]

tessier,

Can't you figure out the period of a 31 KHz square wave? If not, you have a lot of work to do before you will learn anything from LTspice.

Rick

[jcx]

honest questions without pretense are/should be welcomed

[tessier]

Hi

The 31 khz square wave are working but it's all down on the negative side like you can see in my image.

I've only used Ltspice with sine wave in amps simulations.

Thanx

Paul

[sawreyrw]

OK Paul, here's some useful information. The period of a 31 KHz square (or sine) wave is 1/31 KHz=3.226 us. So to make a 31 KHz square wave in LTspice set Tperiod=3.226us, trise=.01u, tfall=.01us, and Ton=1.6us.

[sawreyrw]

jcx,

You answer is way to complex for newbies, and not very useful.

Rick

[gaetan8888]

Originally Posted by sawreyrw

OK Paul, here's some useful information. The period of a 31 KHz square (or sine) wave is 1/31 KHz=3.226 us. So to make a 31 KHz square wave in LTspice set Tperiod=3.226us, trise=.01u, tfall=.01us, and Ton=1.6us.

Hello sawreyrw

There is a small typo error.

1/31 KHz should give 32.26 us

Bye

Gaetan

[jcx]

yes it shows some more advanced spice feautures, but I thought I was clear on how they can be copy/pasted from my post

learning how to get the Spice SW do the calculation seems worth the complication if you're using oddball frequencies with primes too big to count on fingers in their factorizations