"flipper" wrote in message
...
On Fri, 26 Nov 2010 18:18:34 -0000, "Ian Field"
wrote:


"flipper" wrote in message
. ..
On Thu, 25 Nov 2010 18:58:15 -0000, "Ian Field"
wrote:

Some parts of the AN170 PDF for the 555/556 timer are poor quality and
barely readable - it just so happens that the automotive regulator app
is
very blurred.

Also; I have my doubts about the design shown as it shunts the output
(can't
read the resistor value!) and takes its output from a 68 Ohm resistor
feeding the Vcc pin.

Does anyone have any automotive regulator apps for the 555?

The one in AN170 isn't a PWM as such - its just used as a window
comparator
with latch, at least its not a self oscillating PWM, it switches on the
field winding when the battery drops to the low threshold and off when
it
reaches the high thr.

Thanks.


Well, shoot, the attachment failed last time.




Many thanks for the clean scan.


You're welcome.

Comes from never throwing anything away. I've still got my 1985
Signetics Linear LSI Data and Applications manual (because it had so
many app notes).


Sadly my flat is rather small so I have to part with stuff when I'm pretty
sure I'll never need it again.

(Usually get proven wrong 2 days later!).

The only Signetics book I have was published by one of their distributors,
no app notes.