I am looking at a line of miniature rockers current offered in the
Digi-Key catalog
/I posted a msg to several others mentioning that we (in the
/outlands of aviation) would find it most helpful to have
/catalogs from mfgrs simply so that when we order on-line,
/by phone, or whatever, we know what we're buying. That way we
/can intelligently - well, somewhat intelligently - talk to the
/fellow who knows what he is selling. I'd like to find a copy of the
/Digi-Key catalog - along with other electrical component suppliers.
/Could you provide some addresses? I have your book, so I will
/look tonight to see if such is in "the book."
Digikey is in Thief River Falls, Mn. You can order catalogs
from them on their website at . .
www.digikey.com
Also, check with Allied at . . .
www.allied.avnet.com
and Newark at . . .
www.newark.com
and look through the search engines. There are MANY suppliers
of new and good surplus goodies popping up on-line every day
the the three folk above get the bulk of my business.
NOTE!!!!! I said in the earlier post that I was LOOKING at
some swtiches from Digikey, note further that I didn't give specifics
and won't until I can recommend the parts.
/When will you post your on-line catalog? I'm laying out my
/panel now. I have no idea concerning what switches, circuit
/breakers, etc to use at this point. I'm reading your book
/page by page, so the info may be coming up soon.
It will start showing up in pieces in the next few weeks. Dee
is going to take webcrafting lessions as soon as the current
semester is over . . . right now, we both spent the most of the
weekend getting her project ready for presentation. However,
the goodies we'll have to offer are not particularly unique,
just parts that we find to be good value and that we recommend.
//On the subject of Gold Plated Switch Contacts,if any of you
//are giving them serious thoughts then please be aware that are
//about to spend some Big Bucks.Good quality switches , circuit
//breakers , fuses . . .
<snip>
//It is true you can expect to pay a little more but the
//difference in quality justifies price difference.
I disagree. First of all, quantify "quality" . . . If I
spend $25 on a MicroSwitch toggle versus $5 on a Arrow-Hart,
is the $25 switch going to last 5 times as long? It takes
apples for apples comparative anaysis to "justify" a
price difference . . .
//In reference to Digi-Key products you can get quality parts
//from them but you really need to be product wise to determine
//what to buy and what not to buy.
This is like telling your daughter, "Theres a lot of bad
boys out there who just want to take advantage of you," and
walking away without telling her how to tell the good guys
from the bad guys. I can tell you, "the Digikey catalog
contains 10,000 parts of which less than 1% are suitable for use
on airplane electrical systems," I'd be right. However, so brief
a statement may lead some people to believe I meant that most
of Digikey's stuff isn't any good . . . which isn't so . . . most
of their stuff is used to build black boxes . . resistors, capacitors,
etc. etc. and is simply of no interest to amateur airplane builders.
I'd ask folk to be specific in their recommendations either pro
or con . . . speak to the item by part number and supplier or
manufacturer. To caution a buyer to be "product wise" is of
no value.
//In reference to Radio Shack switches I have personally tested
//just about everything they have hanging on their walls. There
//ratings are true BUT the rating is based on the switch being
//energized and why have a switch if you have to keep it in the
//ON position.
Again, the topic of RS switches was going to be very specific
as to style and application. So far, I've not seen anyone recomend
any particular part or any application but we're looking at them
and will post objective findings here. I wrote in an earlier post
that there are hundreds of ways that a switch can be rated and
without being privy to specific data, we simply don't know the
details.
So, we look for parts that will perform for some period of time
and not present a hazard to flight when they fail. Good systems
design and pilot education yields failure tolerant flight systems.
//On the subject of Circuit Breakers as opposed to Fuses, I go
//with the Major manufacturers and opt for circuit breakers.
Just because it's flying around in a few hundred thousand
certified ships doesn't make it the most reliable nor the
best value, it just makes it "certified". I work inside that
arena and I can tell you that many engineers are frustrated
with the way that certification carves designs into stone.
Independence, Kansas, the Jurassic Park of aviation, Cessna
is cloning dinosaurs.
//It is a lot easier to spot a tripped breaker than a fuse
//behind a cap or buried somewhere in the wiring harness.
Why would you look for a tripped breaker? Could it be because you
flipped a switch and nothing happend? Hmmmm . . . suppose the
breaker wasn't tripped? That means the thing broke without
drawing too much current. Suppose the breaker did trip. That
means it broke and DID draw too much current. What was your
first clue that something was broke? How does the observation
that the breaker was tripped/not-tripped help you in your
evaluation?
//BTW in Re: a previous posting about Rick Nelson's DC3 catching
//fire because of repeated resets of a breaker most Engineers
//and Technicians agree that you should reset a breaker or
//replace a fuse ONCE,if it blows again you should know you have
//a problem.Another not so well known fact is the fuse or breaker
//is there to protect the wiring and not the equipment it is wired to.
Most airlines don't allow any breaker resetting in the cockpit.
So . . . I'll ask again, if you could replace $900 worth of breakers
with $35 worth of fuses and free up 30 square inches of panel
space in the process, then you have a place to mount the EXTRA
radio that you can now more likely afford because you didn't spend
it on components that in all probability will never have to act
and when they do, tell you nothing of value.
//On the subject of switches rated at 110 volts AC versus 12 volts
//without getting into the entricies of OHMS Law just take a look
//at a High Voltage transmission line that carries say 28000 volts.
//For simplicity say it is a half inch in diameter. How big would
//it be if the voltage were 110 volts and serving the same number of users?
????? I'm mystified as to the significance of this analogy . . .
When you own a Bonanza or a Kingair you're obligated to pay
going shop rates for installation of parts issued via certified
distribution. It may well be worth $25 to extend the life of a
switch by only two times if the labor to replace it is $100! When
I worked at Electro-Mech about 15 years ago, we did our first
brushless d.c. fan design and offered it to the Citation engineering
manager. It was well received even though it cost over 3 times as
much as the brush-type blower we were currently building.
The reason was that this blower (750 hour service life) got turned
on to keep factory workers in a breeze as soon as the electrical
system was powered up. The blowers left the factory with hundreds
of hours of service on them. Further, the labor to replace the
$280 blower was about $750 . . . it was under a bunch of floorboards
and plumbing. So, to get 6 times the life for three times the cost
was a good trade. COST OF OWNERSHIP is the real quality driver here
folks. When you can replace any switch in your airplane in 5 minutes
with ordinary hand tools, buying $25 dollar switches is more of
a fasion statment than a safety of flight issue. Buy more hand-helds
for back-up and NO gold plated switches . . . you'd be amazed how many
ways a radio can fail and never pop a breaker . . .
Regards,
Bob . . .
AeroElectric Connection
////
(o o)
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