Re: LV2000

From: Anders Knudsen <Anders_Knudsen_at_btc.adaptec.com>
Date: Tue Mar 03 1998 - 12:17:24 EST

At 08:40 AM 3/3/98 -0800, Clay wrote:
>Hi all (and Anders and Jeff in particular)--
>
>Got my LV2000 boards yesterday. I'm quite impressed with the board and
>docs! Good work guys!
>
>One question though... The docs didn't come with a parts list and I
>can't quite make out a couple things on the PCB. Should the bill of
>materials be:
>
>Desc Qty
>6 1N4002
>2 4.3K resistors (1/8th watt or 1/4th?)
>2 47K resistors
>2 240 resistors
>2 .47uF cap (these looked like dipped tants in the
>pictures?)
>4 1uF cap (also looked like dipped tants?)
>1 LM 337T
>1 LM 317T
>2 small LEDs
>
>The only problem area is the caps. The silk screen on my boards is
>pretty unreadable around those-- I can't make out the polarization
>marking on the PCB. Any chance you can post a GIF of the silk-screen?

Yea, it sucks that the silk screen got hosed around those areas. I guess I
didn't pay attention to the pad clearances.
Alright, Clay, why don't you "read" the Assembly docs? ;-)
There *is* a parts list in the assembly docs on page 3.
The caps are dipped tants.
Oh, I'll get jeff to put a parts list that has Mouser numbers up on the web
page so people that need/want to order more parts can get them easily.
Otherwise you can still get parts from Jeff.
On page 3 of the assembly docs, next to the parts list is a picture of the
silk screen. Now I know what you're saying, "I can't read that either." If
you go to http://www.diac.com/~jeffh/lv2000/lv2000as.pdf and then scroll to
page 3, and then zoom in to the silk screen picture, you should see it
pretty clearly.
Other wise, the caps that are around the LM337 all have the positive leads
facing towards the regulator, when placed the cap labels should face out.
The caps that are around the LM317 all have the positive leads facing away
from the regulator, when placed the cap labels should face out.
If you read page 4 of the assembly docs, the description there should match
what I just said.

Here is a crude ASCII graphic (view with courier font). - is the cap
negative lead, + is the cap positive lead. Hold the PCB so you can read the
word LV2000, the negative regulator on the left, the positive regulator on
the right.

(.47u) - + (.47u)
       + -

  (1u) - o o o - (10u) (1u) + o o o + (10u)
       + | | | + - | | | -
          ----- -----
         | | | |
         | | | |
         | | | |
          | | | |
         |_____| |_____|
          LM337 LM317

-Anders.

 -----------------------------------------
| Anders Knudsen
| ASIC Design Engineer
| Adaptec, Inc., Boulder Technology Center
| anders_knudsen@btc.adaptec.com
| http://www.adaptec.com
 =========================================
Received on Tue Mar 3 09:50:31 1998

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