[ARC5] Collins xfmr ratings

[Ian Wilson]

There is a hidden factor of 1130 built into the numbers that Ken
used. This applies for 60Hz, full-wave rectified AC. Since 1000
is easier to remember than 1130, the approximate version has
become popular. Note that the constant 1130 assumes 60Hz.
For a 50Hz you can scale the results by 6/5.

It is convenient, if not particularly rigorous, to use constants without
bothering to state their units. [Nuclear reactor designers please
disregard].

73, ian K3IMW



On Sat, Aug 16, 2014 at 5:43 AM, Brian Clarke <brianclarke01 at optusnet.com.au
> wrote:

> This formula is 'unusual' - I am being polite; in Australia, we would use
> a shorter word. It cannot be calculated because the units are not current.
> What DC voltage? across the choke or across the load? Further, as
> inductance is involved, the frequency must be considered.
>
> Langford-Smith gives a formula for Lcrit as equal to or greater than:
> [Rs + Rl] / 6.pi.f
> Where Rs is all the resistance in series with the diode, Rl is the load
> resistance and f is the supply frequency. This formula only applies to
> full-wave rectification.
>
> He quotes Schade, O H (1943) 'Analysis of rectifier operation', Proc IRE
> 31.7, July, p341.
>
> 73 de Brian, VK2GCE.
>
> On Saturday, August 16, 2014 4:42 PM; Dennis claimed:
>
>
> <snip>.
>
>
>> I (crit) = DC voltage/L (choke inductance in henrys)
>>
>> Dennis D.  W7QHO
>> Glendale, CA
>>
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>