phase linear 400

ABebar

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Warrenville, IL
I'm going to have some time to work on the 400 tonight. I reflowed the solder connections on the bridge rectifier, cleaned them up with alcohol, and mounted in the bottom row of transistors. I also received those AGX-5's and have those in. I'm hoping to get through the entire backplane startup procedure tonight.

The instructions say to "inspect all voltages". My plan was to check B+/B- after each row is added. Is there anything else I should be checking as each row is added? Offset? I have two spring loaded clips on my 2-channel o-scope and a Fluke... Where should those be installed on power up? What's the most critical reading when adding in the drivers?
 

laatsch55

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Check bias as you bring it up after each row . Offset can wait till they are all In.
Rail voltages dont change..
 

wattsabundant

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A few pages back it was mentioned that after power was turned off the output relay clicked after a few seconds. It should go off instantly. I f there is a delay after turn off the AC & DC inputs tothe relay board (connector J3) are are reversed.

Referring to silpads, I happened on to a bin of about 8000 at a surplus shop many years ago. Bought them all. I should be good for a long time yet.
 

laatsch55

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a question....what is the reasoning behind "matching" output transistors...how do you match transistors...
what would happen if a person only changed out one in a channel?? maybe because of lack of resources...
asking for a friend...
No need to match outputs with MJ 21196's
 

gene french

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guayabo de bagaces, guanacaste, costa rica....
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Backplanes are full comp and use MJ21195 and MJ21196 in equal numbers. 8 each for PL400s and 12 each for PL700s
i discovered that...first time i went through your literature....i did not pay too much attention to the chip designations....until now....
i still dont understand what quasi and full complimentary mean....maybe one day, that can be explained to me...
You haven't been paying very good attention NOR read any of the build threads. You gotta do some reading
you are right....after i posted i refered back to some documentation that white oak had sent earlier...and kinda answered my own question....
i guess i should have deleted the post....but, that would have deprived you of the opportunity to fuss at me....
we certainly would not want that....lol
thanks for keeping me honest...
 
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