"Dave M" wrote in message
...
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.


Which manufacturer are you talking about? AN170 could have been published
by any one of dozens of semiconductor manufacturers.


Signetics.

Google AN170 and you'll get loads of 555AN.pdf - every one I found is
blurred on the circuit I might be thinking of using.