Fuel warning light delay

[Ken Smith]

And there is no:

PLC P1.2 ; Pass a large current on bit 2


instruction on any of the PICs I've looked at. As a result, you still
need the output transistor. How much pulling up can a PIC port do?

 

[Fred Bloggs]

So your gauge circuit looks like this:?

+12V
|
[GAUGE]
|
+----E2
|
[SENDER]
|
GND

Where E2 is the voltage going into the emitter of your PNP?

John
Yes,gauge is also grounded ,if that makes any difference

See http://www.caigauge.com/minorgaugefit.htm.

I'm amazed at the interest that this has generated!! Even though most
of it is way over my head.
Any one fancy,drawing up the final circuit ,so a newbie can build it?
Why is it I cant seem to view the circuits in Courier on home PC, but
on work one ,I can?
Many Thanks
Patrick

The original circuit in the link does not work for your gauge/sender, or
anyone else's for that matter, and the two minute timer idea also
stinks. The low fuel indicator on a modern vehicle is a warning light,
and being such would do you no good if it came on just when the tank is
empty. You need to decide on a warning mileage, say Mw, which is the
minimum distance you want to allow yourself to refuel when the indicator
lights. Then if MPG is your worst case miles-per-gallon and C is the
tank capacity, you want the low-fuel warning ON at (Mw/MPG)/C fraction
of full scale reading of the gauge, or 1/16th full scale, whichever is
greater. When the gauge/sender junction voltage falls below this
threshold, the lamp driver should latch on. This mean it comes on and
stays on regardless of subsequent changes in the sender state. The
low-fuel lamp is extinguished when the ignition circuit is turned off.
Most of the time, any accelerations that trip the circuit mean the fuel
level is low enough to alert the driver anyway. It should be rare that
it comes on with more than 2x the low-fuel level setting.

 

[Jim Thompson]

So your gauge circuit looks like this:?

+12V
|
[GAUGE]
|
+----E2
|
[SENDER]
|
GND

Where E2 is the voltage going into the emitter of your PNP?

John
Yes,gauge is also grounded ,if that makes any difference

See http://www.caigauge.com/minorgaugefit.htm.

I'm amazed at the interest that this has generated!! Even though most
of it is way over my head.
Any one fancy,drawing up the final circuit ,so a newbie can build it?
Why is it I cant seem to view the circuits in Courier on home PC, but
on work one ,I can?
Many Thanks
Patrick

The original circuit in the link does not work for your gauge/sender, or
anyone else's for that matter, and the two minute timer idea also
stinks. The low fuel indicator on a modern vehicle is a warning light,
and being such would do you no good if it came on just when the tank is
empty. You need to decide on a warning mileage, say Mw, which is the
minimum distance you want to allow yourself to refuel when the indicator
lights. Then if MPG is your worst case miles-per-gallon and C is the
tank capacity, you want the low-fuel warning ON at (Mw/MPG)/C fraction
of full scale reading of the gauge, or 1/16th full scale, whichever is
greater. When the gauge/sender junction voltage falls below this
threshold, the lamp driver should latch on. This mean it comes on and
stays on regardless of subsequent changes in the sender state. The
low-fuel lamp is extinguished when the ignition circuit is turned off.
Most of the time, any accelerations that trip the circuit mean the fuel
level is low enough to alert the driver anyway. It should be rare that
it comes on with more than 2x the low-fuel level setting.

The low fuel indicator on a modern vehicle is usually simply a
self-heating thermistor immersed in the fuel at about the 2-3 gallon
level. When it gets out of the cooling fluid its resistance drops
rapidly operating a relay.

I had a 280ZX that talked to me, "Fuel is low, the passenger door is
open," etc ;-)

...Jim Thompson

 

[Fred Bloggs]

So your gauge circuit looks like this:?

+12V
|
[GAUGE]
|
+----E2
|
[SENDER]
|
GND

Where E2 is the voltage going into the emitter of your PNP?

--
John Fields
Professional Circuit Designer


John
Yes,gauge is also grounded ,if that makes any difference

See http://www.caigauge.com/minorgaugefit.htm.

I'm amazed at the interest that this has generated!! Even though most
of it is way over my head.
Any one fancy,drawing up the final circuit ,so a newbie can build it?
Why is it I cant seem to view the circuits in Courier on home PC, but
on work one ,I can?
Many Thanks
Patrick

The original circuit in the link does not work for your gauge/sender, or
anyone else's for that matter, and the two minute timer idea also
stinks. The low fuel indicator on a modern vehicle is a warning light,
and being such would do you no good if it came on just when the tank is
empty. You need to decide on a warning mileage, say Mw, which is the
minimum distance you want to allow yourself to refuel when the indicator
lights. Then if MPG is your worst case miles-per-gallon and C is the
tank capacity, you want the low-fuel warning ON at (Mw/MPG)/C fraction
of full scale reading of the gauge, or 1/16th full scale, whichever is
greater. When the gauge/sender junction voltage falls below this
threshold, the lamp driver should latch on. This mean it comes on and
stays on regardless of subsequent changes in the sender state. The
low-fuel lamp is extinguished when the ignition circuit is turned off.
Most of the time, any accelerations that trip the circuit mean the fuel
level is low enough to alert the driver anyway. It should be rare that
it comes on with more than 2x the low-fuel level setting.

The low fuel indicator on a modern vehicle is usually simply a
self-heating thermistor immersed in the fuel at about the 2-3 gallon
level. When it gets out of the cooling fluid its resistance drops
rapidly operating a relay.

I had a 280ZX that talked to me, "Fuel is low, the passenger door is
open," etc ;-)

...Jim Thompson

I can make my Nissan lamp latch on at 1/4 tank when the static level is
more like 1/16th tank.

 

[Ken Smith]

I had a 280ZX that talked to me, "Fuel is low, the passenger door is
open," etc ;-)

I knew someone that had a Dodge something that did that and reminded you
to use your seat belts. It was seriously broken so that every time you
turned it on, you had to listen to this very long list of things that are
wrong.

 

[Fred Bloggs]

I knew someone that had a Dodge something that did that and reminded you
to use your seat belts. It was seriously broken so that every time you
turned it on, you had to listen to this very long list of things that are
wrong.

It was not broken- it was designed for the typical Dodge owner....

 

[Jim Thompson]

It was not broken- it was designed for the typical Dodge owner....

Sno-o-o-o-ort ;-)

...Jim Thompson

 

[Michael A. Terrell]

Sno-o-o-o-ort ;-)

...Jim Thompson

Actually, I'd like to finish the restoration on my '79 Dodge pickup
truck. It was one of 1000 made in a special edition. It came from the
factory with a fiberglass cap, and was painted yellow with a deep brown
wood grain trim. I have a rebuilt engine with a little over 1000 miles
on it, but I still don't have the strength to exchange it with the
original engine. BTW, it has the solid state voltage regulator and
solid state ignition, but no computers.

I saw my VA doctor last week. She changed my Diabetes medicine
again, for the third time in six months. It just doesn't want to come
all the way back down. It was normal for over a year, then my blood
sugar shot up to 497 in a two week period. Its still too close to 200.



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Joseph2k]

Energy is what human life is founded upon. Nobody can move without
energy.

Most of the World's troubles arise from the USA trying to gain control
over the World's energy resources. Oil, natural gas, etc., are the
immediate objectives. They have been quite successful.

But FOOD is itself the greatest energy resource. There's not enough
of it to go round. The Earth's population is already too large.

And so we have the USA selfishly interfering in the World's politics
and economic organisations which ultimately affects the world's
farmers - the ultimate energy producers and generators.

Not that USA citizens are more selfish than the rest of the World. But
being human, they can't help taking advantage of the fact that they
have far more hydrogen bombs than the rest of the World put together.

They also have George Bush. And the British still have Tony Blair.

=======================================

Heck, the US is just following in the footsteps of their forefathers from
Hernan Cortez through the Vikings, the Ottoman Turks, the Romans, the
Greeks, and so on.

 

[Ken Smith]

Ken Smith wrote: [...]

It would be better, wouldn't it, if you could know minute by minute.

Well, my comment was for the benefit of a reader who might decide "hey,
I'll just wait for this non-invasive meter and I'll never prick my
fingers 4 or more times a day".

I had misread your tone. Yes, poking a finger several times a day is way
better than the alternative.

But... the most obvious thing to do, if you know minute by minute, is
to use this to set an insulin pump (in the sci-fi world, an implanted
insulin pump)

Actually that isn't so "scifi". The power could be delivered through the
skin by AC coupling. Unlike a pacemaker, it wouldn't have to have its own
batteries. If it is shut down for a few minutes nothing very bad will
happen.

to mimic a "healthy" pancreas. Here we get to employ
everything we know about embedded servo stabilization.

Actually it doesn't even really need to be "stable". It could oscillate
by 10% and it wouldn't matter. I think that if I was designing such a
thing, I'd add a dither to the output and monitor the input for the
resulting dither. It would allow me to check that the measurement process
was really working.

Otherwise, minute by minute is probably just too much information. I
mean, I like wide-bandwidth probes more than the average guy, but I
don't know what I'd do with so much information!

Your wrist watch updates every second. You deal with this by from only
glancing at it from time to time. I think your mind would deal with it in
the same sort of way.

 

[Rich Grise, but drunk]

Energy is what human life is founded upon. Nobody can move without
energy.

What have you been reading? Everyone knows that man does not live on
bread alone. As for women I think they want peanut butter on theirs too.

[...]

But FOOD is itself the greatest energy resource. There's not enough
of it to go round. The Earth's population is already too large.

Are you going to reduce it by one any time soon?

http://www.churchofeuthanasia.org/e-sermons/butcher.html

Cheers!
Rich
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