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.


While that circuit is pretty much like my original alternator
regulator chip (see my patents), that's NOT the way to make a good
regulator.

Go PWM. All it takes is a comparator watching the 555 ramp.

And fit to this TC:

http://analog-innovations.com/SED/Al...egulatorTC.pdf

...Jim Thompson
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