[eagle] Re: CAN-Do-Too!

Juan Rivera juan-rivera at sbcglobal.net
Mon Jul 16 20:12:49 PDT 2007


Check,

OK.  I just ordered some parts I need to look into the ripple but I forgot
about this.  I'll wait to see what comes up with the supply...

Juan

-----Original Message-----
From: Chuck Green [mailto:greencl at mindspring.com] 
Sent: Monday, July 16, 2007 7:28 PM
To: juan-rivera at sbcglobal.net
Cc: 'Dave Black ((Work))'; 'David Smith'; 'AMSAT Eagle'; 'Samsonoff at Mac.
Com'; 'Louis McFadin'
Subject: Re: CAN-Do-Too!

Hi Juan,

I think you are referring to an e-mail I sent out. It was simply a 
suggestion to verify the hypothesis that the power supply is in a low 
power idle mode and hence the 5kHz you were seeing. It really doesn't 
matter if someone is going to redesign the power supply anyway.

I don't have any shielded inductors to send you. There may not be any 
such thing in the same footprint as the inductor used. But even if it 
has to be cobbled in somehow, it would be a good test to run. If anyone 
has such an inductor, or knows the part number of such a device, it 
might be worth getting one. But again, if someone is going to redesign 
the power supply anyway, I would assume they will at least use a toroid, 
and possibly a shielded one.

Chuck

Juan Rivera wrote:
>
> Chuck,
>
> I seem to recall that you wanted me to try loading down the CAN-Do 
> switcher to see if the frequency went up. Was that you? I can't find 
> the email. If it was, what additional load do you want me to apply? 
> And are you going to send me some shielded inductors to test? Let me 
> know and I'll jump on it for you.
>
> 73,
>
> Juan
>
> ------------------------------------------------------------------------
>
> *From:* eagle-bounces at amsat.org [mailto:eagle-bounces at amsat.org] *On 
> Behalf Of *Louis McFadin
> *Sent:* Monday, July 16, 2007 6:10 PM
> *To:* Chuck Green
> *Cc:* Dave Black ((Work)); Dave Black ((Home)); David Smith; AMSAT 
> Eagle; Samsonoff at Mac. Com; Juan.Rivera ((Work))
> *Subject:* [eagle] Re: CAN-Do-Too! ??????????
>
> Chuck,
>
> Mouser has a very large selection of D-sub connectors including the 
> high density versions. Most are in stock.
>
> I see no inherent reason for not using them.
>
> Lou McFadin
>
> W5DID
>
> w5did at mac.com <mailto:w5did at mac.com>
>
>
>
> On Jul 16, 2007, at 7:19 PM, Chuck Green wrote:
>
>
>
> I have had one experience with the high density D connectors. They 
> were much larger pin count than 9 or 15! After someone absolutely 
> insisted that we use them I did the board lay out. Turned out that 
> they were *totally* unavailable!!! I did the board layout again@#$%&^* 
> using standard Sub-D's. That was a number of years ago so I would hope 
> things have changed. If someone is absolutely confident they can 
> obtain the parts we need then I'm not at all opposed to using them 
> (remember, I'm not volunteering to do parts procurement for this 
> project; this is a good time to use someone that's good at parts 
> procurement).
>
> While at Goddard for P3D vib test I noticed NASA satellites using 
> standard Sub-D's. That was also a few years ago. Anyone know of High 
> Density Sub-D's being used on other satellites?
>
> Chuck
>
> Bdale Garbee wrote:
>
>> On Tue, 2007-07-10 at 09:02 -0700, Chuck Green wrote:
>>
>>> The sub-miniature D connector series has served us well. If anyone 
>>> has *experience* with something they think might be a better choice, 
>>> we'd love to hear about it.
>>>
>> At the AMSAT annual meeting that was held near Washington, D.C., a
>>
>> couple of years ago (three?), someone approached me after the CAN-Do!
>>
>> talk that Stephen and I gave to ask why we weren't using the
>>
>> higher-density connectors that put 15 pins in the same shell size as the
>>
>> 9-pin version of the series we have been using... and followed up by
>>
>> sending me what looked like mil/aero-spec samples of such a part that I
>>
>> probably still have in my basement somewhere. I'm sorry that I can't
>>
>> recall at all who that person was, but it was someone who claimed to be
>>
>> using such connectors professionally with good results.
>>
>> At the time, we weren't likely to be redesigning the units any time
>>
>> soon, so I didn't take any action on this suggestion. If we're going to
>>
>> revisit the design and think we need more than 9 pins, it might be worth
>>
>> investigating higher density connectors like that?
>>
>> Bdale
>>




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