[time-nuts] One sure way to kill your FE-5680A or FE-5650A
kb8tq at n1k.org
Thu Jun 9 13:11:07 EDT 2016
Their design is hardly unique in not having a dedicated supervisory part in it.
There are a *lot* of designs that work very well using basically the same
parts they use, without using a reset chip.
Without a lot of digging into exactly what is going on, there isn’t much of a
way to be sure of a fix.
One very real possibility is: The reason we *have* all these parts is that they
have a bug in them, and were scrapped out because of it.
> On Jun 9, 2016, at 8:03 AM, Clint Jay <cjaysharp at gmail.com> wrote:
> It would seem so bit I don't remember seeing a 'reset' chip in the 5680.
> I'm wondering if there's scope to add one onto the rail that runs the PSD
> and 80C320 to keep it in reset.
> On 9 Jun 2016 13:00, "Bob Camp" <kb8tq at n1k.org> wrote:
>> Based on the number of different ways there seem to be to corrupt the
>> operating software
>> in the FE Rb’s …. they seem to have a unique problem. There are a *lot* of
>> using the same basic parts that don’t turn into a brick when this or that
>>> On Jun 9, 2016, at 4:31 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
>>>> The ATTinys have brownout detectors in them that’s supposed to keep them
>>>> from going bonkers during undervolt periods.
>>> Startup and/or brownout has long been a nasty problem area for digital
>>> In the old old days, there was typically a R/C delay on the reset pin to
>>> CPU. That screwed up when the power supply ramped up slowly enough.
>>> old timers have that merit badge.
>>> Modern CPU chips often have specs like power must be OK for 200 ms before
>>> releasing Reset. Anything like that will have at least one corresponding
>>> power monitor chip with several supply voltage inputs and the appropriate
>>> The brownout side gets ugly when you look at the tolerances. The
>>> on the power monitor subtracts from the power supply tolerances.
>>> There is another worm in the can. How long does it take for your
>>> to get going?
>>> These are my opinions. I hate spam.
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