Discussion:
Tech: EZSBC
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LexingtonVAPin
2021-08-26 21:12:52 UTC
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On WPC89 boards, when subbing the EZSBC for the LM323, do you leave the
heat sink in place?
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http://orcalcoast.com/
Joseph 'Tony' Dziedzic
2021-08-28 19:27:23 UTC
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Post by LexingtonVAPin
On WPC89 boards, when subbing the EZSBC for the LM323, do you leave the
heat sink in place?
--
http://orcalcoast.com/
The manufacturer states a heat sink is not required to maintain the maximum output current of 3 amps AT ROOM TEMPERATURE; since the inside of the backbox is at a somewhat elevated temperature I retain the original heat sink as a safety precaution. Be sure to replace the #6 KEPS nuts (captive lock nuts) used to mount the original regulator with discrete #6 split lock washers and #6 nuts; the toothed lock washer of the KEPS nut can overlap components on the surface of the printed circuit board.

Joseph "Tony" Dziedzic
LexingtonVAPin
2021-08-29 16:58:12 UTC
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Post by Joseph 'Tony' Dziedzic
Post by LexingtonVAPin
On WPC89 boards, when subbing the EZSBC for the LM323, do you leave the
heat sink in place?
--
http://orcalcoast.com/
The manufacturer states a heat sink is not required to maintain the maximum output current of 3 amps AT ROOM TEMPERATURE; since the inside of the backbox is at a somewhat elevated temperature I retain the original heat sink as a safety precaution. Be sure to replace the #6 KEPS nuts (captive lock nuts) used to mount the original regulator with discrete #6 split lock washers and #6 nuts; the toothed lock washer of the KEPS nut can overlap components on the surface of the printed circuit board.
Joseph "Tony" Dziedzic
Thanks Tony. I found the same thing for the KEPS nuts. I used a #6
(small) tooth washer that does not extend beyond the nut. On one side, I
could not get a nut driver on a regular nut because of the lack of
clearance with a component.

I thought about reversing the screw and nut on the board, but found that
the nut crosses over other traces on the back of the board, so that was
not a good idea. I was a bit surprised that only one screw is grounded
(unless I missed it on the front of the board).

I left the heat sink on just in case. I appreciate your response that
confirms it is a good idea to leave it in place.

Larry
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http://orcalcoast.com/
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