Re: [N8VEM-S100:1137] S-100 SMB and S-100 bus extender PCBs status

[Tom Lafleur <laf...@lafleur.us>]

the Vdrop (~500mv) on the part is 1/2 of the 7805 (1v) , so less power
dissipate in the part...




On Wed, Oct 10, 2012 at 11:10 AM, monahanz <mon...@vitasoft.org> wrote:
> Interesting Tom, have not used them. Are you sure the L4940-5 will generate
> less heat. The S100 8V line is kind of fixed at that. I know the L4940-5 can
> work with voltages just above 5V, but I would think it would have to burn
> off the excess 8 Volts as heat anyway.
>
> BTW for people building the SMB, be sure to get the 1.5A voltage regulators
> ( Jameco # 1130069 etc) not the 1A ones.
>
> John
>
>
>
> On Monday, October 8, 2012 9:39:22 PM UTC-7, Tom Lafleur wrote:
>>
>> Another option that will lower the heat load is to use a low drop out
>> regulator like the L4940-5
>>
>> tom...
>>
>>
>>
>> On Mon, Oct 8, 2012 at 9:21 AM, John Monahan <mon...@vitasoft.org> wrote:
>> > One thing I have yet to add to the web page for this board -- the 5V
>> > regulator runs a little hot on that board (due to the hex displays).
>> > Unfortunately the regulator is a bit too far to the left on the board.
>> > You
>> > need to drill a hole off center on the heat sink to use a large one.
>> > I'm
>> > traveling will write this up later in the week.
>> >
>> > John
>> >
>> >
>> > Sent from my iPhone
>> >
>> > On Oct 8, 2012, at 8:30 AM, "Andrew Lynch" <LYN...@YAHOO.COM> wrote:
>> >
>> > Hi!
>> >
>> > Good news!  The S-100 SMB and S-100 bus extenders are going out to their
>> > builders!  I’ve sent email to everyone remaining on the waiting list and
>> > the
>> > remaining PCBs are basically available in case anyone else would like
>> > them.
>> > Please contact me.  Thanks and have a nice day!
>> >
>> > Andrew Lynch
>> >
>> >
>> >
>> > PS, John uses his SMB all the time and it has been very useful in the
>> > debugging of the latest S-100 80386 CPU prototype board.  Really more
>> > good
>> > news to come soon!
>>
>>
>>
>> --
>> ~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~
>>
>> Tom Lafleur
>> (858) 759-9692



-- 
~~ _/) ~~~~ _/) ~~~~ _/) ~~~~ _/) ~~

Tom Lafleur
(858) 759-9692