On Mon, 16 Jan 2012 09:01:48 -0800, John Larkin
wrote:
On Mon, 16 Jan 2012 16:04:10 -0000, "Ian Field"
wrote:
"John Larkin" wrote in message
. ..
On Sun, 15 Jan 2012 22:15:02 -0000, "Ian Field"
wrote:
"Jim Thompson" wrote
in
message ...
On Sun, 15 Jan 2012 16:43:18 -0500, "Martin Riddle"
wrote:
"Jim Thompson" wrote
in message ...
Here you go...
http://analog-innovations.com/SED/Bi...ubSwitcher.pdf
I figure, if you had a mind to, you could add regulation by running
this dude in burst mode, by stopping the 555 via its RESETbar input.
Ian, Take note-------^^^^^^^^^^
Diode D7 prevents some really weird behavior from back conduction. If
there were a need to tighten up the efficiency, I'd replace it with
another P-channel, body in the opposite direction from MP1 (for lack
of finding a suitable transistor, modeled as a 0.3 Ohm device
extrapolated from my vast CMOS device library :-). Then I'd use a
comparator to make the drop like a near ideal diode as in...
http://analog-innovations.com/SED/Pe...rIsolation.pdf
Component values included!
Cheers
I always do that. I had that info the very first day, as I alluded in
an early post (I verbally provided the results, same as the sims now
posted... which got me "naa, naa, naa poo poo"), so I just let Larkin
run off at the mouth, just for the sport of it ;-)
...Jim Thompson
You might impress a few simple people, but it certainly won't do what I
set
out to achieve.
Really? It supports the lamp load AND charges the battery.
JF will love it, since it has a 555.
It may have been possible to achieve something aproximating to regulation by
externally pulling the 5k/5k/5k divider, but it would be a huge comromise.
Why would it "be a huge com[p]romise" ? But you might have stability
issues.
There's a schematic taking shape and tempting me to put pen to paper.
So show us... don't be a reductive Larkin replication :-)
But I'm inclined not to do it all for the 2 principle knowitalls that in
reality don't know a fraction of what they'd like us to believe.
What a bull-**** artist!
I don't think the problem has been clearly stated. What is this
circuit supposed to do, and what is the user interface? Jim's circuit
leaves the lights on all the time,
The only "user interface" would be to pedal the bike. Add a switch
for daytime use.
I thought the object was to have the battery provide power when the
bicycle stops at an intersection, or do you prefer to be rear-ended by
a car when your tail-light goes out? Here in AZ a moonless night can
have you unable to see your own hand in front of your eyes.
runs the 555 all the time,
You have some problem installing a switch where RBAT is in the
drawing? Maybe use a DPDT switch and disconnect the dynamo during
daylight, though I'd opt to charge the battery during the day.
and
loads the alternator whenever it can,
I don't know what you're harping about... it loads the alternator
whenever the dynamo voltage exceeds the battery voltage. (I'd
regulate using burst mode myself... easier to make completely stable.)
and probably blows out the fets
"Probably" ??
Here's what the dynamo looks like open and shorted....
http://www.analog-innovations.com/SE...Evaluation.pdf
50s time point is same as 50kmph bicycle speed. PDF shows ramp up
from zero speed. Protecting gates is trivial.
now and then. That doesn't sound like what anybody would want on their
bicycle.
And who wants to lug around a 20 mH power inductor
Here's a 5mH, 5 AMP, yes AMPERES, inductor for my CDI ignition, 20mH
at 0.5 Amp would be substantially smaller...
http://www.analog-innovations.com/SED/CDI_Inductor.jpg
that dissipates a
couple of watts?
John
Tell us, John, how did you calculate that "couple of watts"?
...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at
http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.