>>On 02/07/2011 10:02 PM, rashmi venugopal wrote:
>>> is fir filter is benificial or the iir filter for the application to
>>> measure the total harmonic distortion in metering equipment.
>>> and also reasons to select particular filter,
>>>
>>> fir requires more memory than iir,, but iir is not a linear phase,,
>>
>>Does linear phase matter if you just want to know power magnitude?  FIR 
>>filters require memory in inverse proportion to their bandwidths, while 
>>IIR filters require memory in something like -A*log(bandwidth).  What 
>>sort of bandwidth requirements do you think a total harmonic distortion 
>>analyzer requires?
>>
>>-- 
>>
>>Tim Wescott
>>Wescott Design Services
>>http://www.wescottdesign.com
>>
>>Do you need to implement control loops in software?
>>"Applied Control Theory for Embedded Systems" was written for you.
>>See details at http://www.wescottdesign.com/actfes/actfes.html
>>
>is fir filter is benificial or the iir filter for the application to
>measure the total harmonic distortion in metering equipment. and also
>reasons to select particular filter,
>as per the FIR uses more memory,, but the IIR uses less memory but it
does
>not show linear phase response,,
>
>our metering equipment bandwidth is 45 - 65 hz, so now we have to
implents
>the coefficients which we get from the filter design to the meters so
that
>to measure total harmonic distortion,, now what to do,,, which filter to
>use,, 
>This Message is Moderated
>
>memory of the meters which we are using is 60 kb and 40kb souce code will
be accuired,, in remaing 20 kb we need to implemnt designed filters,,
so ehich filter will be suitable,, to measure THD in the meters,
>
>

>>On 02/07/2011 10:02 PM, rashmi venugopal wrote:
>>> is fir filter is benificial or the iir filter for the application to
>>> measure the total harmonic distortion in metering equipment.
>>> and also reasons to select particular filter,
>>>
>>> fir requires more memory than iir,, but iir is not a linear phase,,
>>
>>Does linear phase matter if you just want to know power magnitude?  FIR 
>>filters require memory in inverse proportion to their bandwidths, while 
>>IIR filters require memory in something like -A*log(bandwidth).  What 
>>sort of bandwidth requirements do you think a total harmonic distortion 
>>analyzer requires?
>>
>>-- 
>>
>>Tim Wescott
>>Wescott Design Services
>>http://www.wescottdesign.com
>>
>>Do you need to implement control loops in software?
>>"Applied Control Theory for Embedded Systems" was written for you.
>>See details at http://www.wescottdesign.com/actfes/actfes.html
>>
>is fir filter is benificial or the iir filter for the application to
>measure the total harmonic distortion in metering equipment. and also
>reasons to select particular filter,
>as per the FIR uses more memory,, but the IIR uses less memory but it
does
>not show linear phase response,,
>
>our metering equipment bandwidth is 45 - 65 hz, so now we have to
implents
>the coefficients which we get from the filter design to the meters so
that
>to measure total harmonic distortion,, now what to do,,, which filter to
>use,, 
>This Message is Moderated
>
>memory of the meters which we are using is 60 kb and 40kb souce code will
be accuired,, in remaing 20 kb we need to implemnt designed filters,,
so ehich filter will be suitable,, to measure THD in the meters,
>
>

>On 02/07/2011 10:02 PM, rashmi venugopal wrote:
>> is fir filter is benificial or the iir filter for the application to
>> measure the total harmonic distortion in metering equipment.
>> and also reasons to select particular filter,
>>
>> fir requires more memory than iir,, but iir is not a linear phase,,
>
>Does linear phase matter if you just want to know power magnitude?  FIR 
>filters require memory in inverse proportion to their bandwidths, while 
>IIR filters require memory in something like -A*log(bandwidth).  What 
>sort of bandwidth requirements do you think a total harmonic distortion 
>analyzer requires?
>
>-- 
>
>Tim Wescott
>Wescott Design Services
>http://www.wescottdesign.com
>
>Do you need to implement control loops in software?
>"Applied Control Theory for Embedded Systems" was written for you.
>See details at http://www.wescottdesign.com/actfes/actfes.html
>
is fir filter is benificial or the iir filter for the application to
measure the total harmonic distortion in metering equipment. and also
reasons to select particular filter,
as per the FIR uses more memory,, but the IIR uses less memory but it does
not show linear phase response,,

our metering equipment bandwidth is 45 - 65 hz, so now we have to implents
the coefficients which we get from the filter design to the meters so that
to measure total harmonic distortion,, now what to do,,, which filter to
use,, 
This Message is Moderated

>On 02/07/2011 10:02 PM, rashmi venugopal wrote:
>> is fir filter is benificial or the iir filter for the application to
>> measure the total harmonic distortion in metering equipment.
>> and also reasons to select particular filter,
>>
>> fir requires more memory than iir,, but iir is not a linear phase,,
>
>Does linear phase matter if you just want to know power magnitude?  FIR 
>filters require memory in inverse proportion to their bandwidths, while 
>IIR filters require memory in something like -A*log(bandwidth).  What 
>sort of bandwidth requirements do you think a total harmonic distortion 
>analyzer requires?
>
>-- 
>
>Tim Wescott
>Wescott Design Services
>http://www.wescottdesign.com
>
>sir,, band width is 45 - 65 hz,, the memory less and also we need linear
phase,, so if i use FIR filter then memory constraint,, is there any
techniquie to adjust the memory usage so that we can implement FIR
filter,,

>On 02/07/2011 10:02 PM, rashmi venugopal wrote:
>> is fir filter is benificial or the iir filter for the application to
>> measure the total harmonic distortion in metering equipment.
>> and also reasons to select particular filter,
>>
>> fir requires more memory than iir,, but iir is not a linear phase,,
>
>Does linear phase matter if you just want to know power magnitude?  FIR 
>filters require memory in inverse proportion to their bandwidths, while 
>IIR filters require memory in something like -A*log(bandwidth).  What 
>sort of bandwidth requirements do you think a total harmonic distortion 
>analyzer requires?
>
>-- 
>
>Tim Wescott
>Wescott Design Services
>http://www.wescottdesign.com
>
>sir,, band width is 45 - 65 hz,, the memory less and also we need linear
phase,, so if i use FIR filter then memory constraint,, is there any
techniquie to adjust the memory usage so that we can implement FIR
filter,,