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Reverse Polarity and Over Voltage Protection Design 
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Joined: Tue Jan 15, 2008 2:31 pm
Posts: 15204
Location: Home sweet home!
I don't know, how about a jaycar rr2502? :-p

OK, newark = farnell, but I'm still not a fan of this method of description. Wouldn't "how does hole spacing at 15.06mm sound?" be better?

From the data sheet I'm guessing that we would have the pads 15.06mm apart?

Second question, why are we at 2.5W with a maximum load ever on a bad day when a second CPU snuck in and sat on top of the other one with a bunch of accessories of 1 Watt and a normal usage of around 0.1125 Watts and probably maximum of 0.25 Watts. A 1 Watt part makes more sense to me and a 1/4W would do, but you would never use that for this application...

Even though newark is farnell, the part numbers are different. Your newark number corresponds to this farnell (most countries) number 1155286


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Sun Aug 17, 2008 9:59 am
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1N4001 - Signed up
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Joined: Tue Jun 10, 2008 5:17 pm
Posts: 1607
I see the 2.5 watt comes in a $.42 so I'm not to concerned about pushing the tolerance on the lower power rating. We can probably get by with a smaller resistor, but we might want this larger resistor, so I'm planning on allowing it at least for now.

The R7 foot print appears to come with .05in via's and .7in hole to hole spacing. The R6 foot print comes with .045in via's hole to hole .65in. R5's vias are .030in vs the required .040in for the leads. So R5 is out of the game. I choose the R7 because even though the R6 vias are over sized, it would still be a tight fit.

Sun Aug 17, 2008 10:55 am
QFP80 - Contributor

Joined: Sat Jul 26, 2008 1:08 pm
Posts: 42
The Kicad footprints cannot be altered? New footprints cannot be designed? Just asking, I'm running Win98 which won't run Kicad. Sorry slightly off-topic but we need free footprints to go with Free EMS.

Sun Aug 17, 2008 1:14 pm
1N4001 - Signed up
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Joined: Tue Jun 10, 2008 5:17 pm
Posts: 1607
The KICAD footprints (modules) can be alerted and new footprints can be designed. I've posted about a couple I've alerted/designed in the layout thread.

I don't alter the standard footprints (or symbols) to prevent issues with other installations on other machines. I also include the libraries that include both modules and symbols in each release, which is covered under free licencing.

Sun Aug 17, 2008 2:02 pm
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