Started by August 10, 2006
```Hello

I need to convert a lead/lag filter to a z transform function. I'll be
using the bilinear method.

Question, what equation do I use for prewraping the lead and lag times??
For the other filters i've converted i was prewrapping the frequency and
using rads/sec. For the lead/lag filters I only have a time constant input.

Transfer function is

T1*s + 1
g(s) ----------
T2*s + 1

Thanks
```
```Toro wrote:
> Hello
>
> I need to convert a lead/lag filter to a z transform function. I'll be
> using the bilinear method.
>
> Question, what equation do I use for prewraping the lead and lag times??
> For the other filters i've converted i was prewrapping the frequency and
> using rads/sec. For the lead/lag filters I only have a time constant input.
>
> Transfer function is
>
>       T1*s + 1
> g(s) ----------
>       T2*s + 1

T = 1/&omega; = 1/2&pi;f
--
Engineering is the art of making what you want from things you can get.
&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;&macr;
```
```Jerry Avins <jya@ieee.org> wrote in news:bdWdnaHIL-VdyUbZnZ2dnUVZ_t-
dnZ2d@rcn.net:

>
> T = 1/&#2013265944;% = 1/2&#2013265944; f
> --

That got real messed up in plain text, Jerry.

--
Scott
```
```Scott Seidman wrote:
> Jerry Avins <jya@ieee.org> wrote in news:bdWdnaHIL-VdyUbZnZ2dnUVZ_t-
> dnZ2d@rcn.net:
>
>> T = 1/&#2013265944;% = 1/2&#2013265944; f
>> --
>
> That got real messed up in plain text, Jerry.

UTF 8, Western (ISO8859-1)

Tau = 1/omega = 1/2pi*f

Jerry
--
Engineering is the art of making what you want from things you can get.
&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
```
```Jerry Avins <jya@ieee.org> wrote in
news:UJWdnbn2RsCXwEbZnZ2dnUVZ_rydnZ2d@rcn.net:

> Scott Seidman wrote:
>> Jerry Avins <jya@ieee.org> wrote in news:bdWdnaHIL-VdyUbZnZ2dnUVZ_t-
>> dnZ2d@rcn.net:
>>
>>> T = 1/&#2013265944;% = 1/2&#2013265944; f
>>> --
>>
>> That got real messed up in plain text, Jerry.
>
> UTF 8, Western (ISO8859-1)
>
> Tau = 1/omega = 1/2pi*f
>
> Thanks for the heads up.
>
> Jerry

Thanks for the response. Is the 'f' in Hz or in radians/sec? If in Hz
then all I need to do is take the invers of T1 and T2 inputs, is this
correct?

How about if in rad/sec, do I take the inverse and multiply by 2*pi??? Or
am I missing something here???

thanks again
```
```Toro wrote:
> Jerry Avins <jya@ieee.org> wrote in
> news:UJWdnbn2RsCXwEbZnZ2dnUVZ_rydnZ2d@rcn.net:
>
>> Scott Seidman wrote:
>>> Jerry Avins <jya@ieee.org> wrote in news:bdWdnaHIL-VdyUbZnZ2dnUVZ_t-
>>> dnZ2d@rcn.net:
>>>
>>>> T = 1/&#2013265944;% = 1/2&#2013265944; f
>>>> --
>>> That got real messed up in plain text, Jerry.
>> UTF 8, Western (ISO8859-1)
>>
>> Tau = 1/omega = 1/2pi*f
>>
>> Thanks for the heads up.
>>
>> Jerry
>
> Thanks for the response. Is the 'f' in Hz or in radians/sec? If in Hz
> then all I need to do is take the invers of T1 and T2 inputs, is this
> correct?
>
> How about if in rad/sec, do I take the inverse and multiply by 2*pi??? Or
> am I missing something here???

f is cycles per second. w is radians per second. (It should really be ?;
lower-case omega, but not everyone sees that properly.) w = 2*pi*f.
That's EE 101. Glad to help, but I assumed I didn't need to. My error.

Jerry
--
Engineering is the art of making what you want from things you can get.
&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
```
```Jerry Avins <jya@ieee.org> wrote in news:---
dnZc50eODBn_ZnZ2dnUVZ_o6dnZ2d@rcn.net:

> That's EE 101.

But if I had a dime for every time I've been off by a factor of 2pi ....

--
Scott