Re: Looking for Microcontroller Recommendations

On Sat, 16 Jan 2010 20:36:41 +0100, Falk Willberg
<(E-Mail Removed)> wrote:

>RogerN wrote:
>...
>> That would be a nice microcontroller project, use a temperature
>> sensor and RTCC, if it's freezing out, start the car so many minutes before
>> the end of shift, the colder it is, the more warm up time is allowed.
>
>Are you really going to waste 50% gas by blowing warm air (and harmful
>gases) out of the exhaust, torture the engine by running it cold and
>idle for minutes?

50%? The car isn't "tortured" by running it at idle. OTOH, it isn't
good running a car at high speed until it's warmed some. The car
needs to be started anyway. It may "waste" a little gas by idling a
*little* longer than normal.

>Why not use an auxiliary heater and control this with a micro?
>That would be a smart approach.

With what are you going to power this "heater". Electricity (from
where?) rather than waste heat?

On Sat, 16 Jan 2010 21:54:26 +0100, Falk Willberg
<(E-Mail Removed)> wrote:

>krw schrieb:
>> On Sat, 16 Jan 2010 20:36:41 +0100, Falk Willberg
>> <(E-Mail Removed)> wrote:
>>
>>> RogerN wrote:
>>> ...
>>>> That would be a nice microcontroller project, use a temperature
>>>> sensor and RTCC, if it's freezing out, start the car so many minutes before
>>>> the end of shift, the colder it is, the more warm up time is allowed.
>>> Are you really going to waste 50% gas by blowing warm air (and harmful
>>> gases) out of the exhaust, torture the engine by running it cold and
>>> idle for minutes?
>>
>> 50%?
>
>A rough guess. Hot exhaust gases, heat radiation...

It's *all* waste of you aren't going anywhere.

>> The car isn't "tortured" by running it at idle. OTOH, it isn't
>> good running a car at high speed until it's warmed some.
>
>Running an engine at low temperatures causes a lot of wear. Starting it
>and drive at reasonably low RPM is the best way to reach operating
>temperature in short time.

Nonsense. The wear is at least as great by driving it at any speed as
it is by letting it idle. You *should* idle at least as long as it
takes to get off high-idle. Some recommend warming then engine
completely.

>> The car
>> needs to be started anyway. It may "waste" a little gas by idling a
>> *little* longer than normal.
>
>The amount of waste depends on what you consider a "little longer".

Long enough for the engine to come up to temperature.

>>> Why not use an auxiliary heater and control this with a micro?
>>> That would be a smart approach.
>>
>> With what are you going to power this "heater". Electricity (from
>> where?) rather than waste heat?
>
>Not necessarily electricity. This is common practice in Scandinavia.

Anything other than waste heat is even more energy wasted.

>Auxiliary heaters can be powered with gas or diesel. Besides that there
>are two types. One heat the coolant, thus heating the car's inside and
>avoid cold starting the engine.

You're going to have a gasoline fire burning to keep the engine warm?

>The other type only heats the inside of the vehicle.

....and you bitch about "wasting" a little gas.

>Both have a much better efficiency than an idling engine.

Nonsense. Heat from the engine is free.

>http://www.webasto.us/am/en/am_auto_heaters.html
>
>Falk

krw <(E-Mail Removed)> wrote:

>On Sat, 16 Jan 2010 20:36:41 +0100, Falk Willberg
><(E-Mail Removed)> wrote:
>
>>RogerN wrote:
>>...
>>> That would be a nice microcontroller project, use a temperature
>>> sensor and RTCC, if it's freezing out, start the car so many minutes before
>>> the end of shift, the colder it is, the more warm up time is allowed.
>>
>>Are you really going to waste 50% gas by blowing warm air (and harmful
>>gases) out of the exhaust, torture the engine by running it cold and
>>idle for minutes?
>
>50%? The car isn't "tortured" by running it at idle. OTOH, it isn't
>good running a car at high speed until it's warmed some. The car
>needs to be started anyway. It may "waste" a little gas by idling a
>*little* longer than normal.
>
>>Why not use an auxiliary heater and control this with a micro?
>>That would be a smart approach.
>
>With what are you going to power this "heater". Electricity (from
>where?) rather than waste heat?

There are special heaters for this purpose. They heat the engine
coolant and can also heat the interior. Ofcourse they use fuel but it
is a lot better than letting the engine run idle.

http://www.webasto.us/home/en/homepage.html


--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

On Sat, 16 Jan 2010 23:26:34 +0100, Falk Willberg
<(E-Mail Removed)> wrote:

>krw schrieb:
>> On Sat, 16 Jan 2010 21:54:26 +0100, Falk Willberg wrote
>
>...
>
>>> Running an engine at low temperatures causes a lot of wear. Starting it
>>> and drive at reasonably low RPM is the best way to reach operating
>>> temperature in short time.
>>
>> Nonsense. The wear is at least as great by driving it at any speed as
>> it is by letting it idle. You *should* idle at least as long as it
>> takes to get off high-idle. Some recommend warming then engine
>> completely.
>
>I don't know wether this is true for ancient engine designs.

It's true for *all* engines. Until the oil is moving it's best not to
demand too much from the engine.

>The manual
>of my car (Peugeot Diesel, 2000 model) recommends to start the engine
>and immediatly drive at low RPM. Even the very simple engine of my
>motorcycle[0] does not require any warm up.

You probably believe you can go 10000 miles on an oil change too.

>>>> The car
>>>> needs to be started anyway. It may "waste" a little gas by idling a
>>>> *little* longer than normal.
>>> The amount of waste depends on what you consider a "little longer".
>>
>> Long enough for the engine to come up to temperature.
>
>Warming up idling obviously takes more time.

Some. Time that you aren't freezing your ass off.

>>> Auxiliary heaters can be powered with gas or diesel. Besides that there
>>> are two types. One heat the coolant, thus heating the car's inside and
>>> avoid cold starting the engine.
>>
>> You're going to have a gasoline fire burning to keep the engine warm?
>
>Sure, why not? But it is not a simple fire. Thos auxiliary heaters work
>similiar to a Coleman lamp but do not have to emit light.

I know how they work. It's still a stupid idea. Air-cooled cars have
little choice but there is a *ton* of free and easy heat available
from a water cooled engine. An auxiliary heater for the few cold days
in the cold climates makes no sense at all.

>>> The other type only heats the inside of the vehicle.
>>
>> ...and you bitch about "wasting" a little gas.
>
>Blowing hot "air" through the exhaust without need is waste. Heating
>with ~90% efficiency is much less waste.

Heating with waste heat is free. You have to count the entire life
cycle of the car.

>>> Both have a much better efficiency than an idling engine.
>>
>> Nonsense. Heat from the engine is free.
>
>Sorry, I did not know, that in the U.S. gas is free if your vehicle is
>not moving ;-)

Look at the total cost of ownership. The few minutes warming a car up
when it's <0F isn't a big deal. The cost of another heater, as
options only for the few who want it would be.

On Sun, 17 Jan 2010 09:34:28 +0100, Falk Willberg
<(E-Mail Removed)> wrote:

>krw schrieb:
>> On Sat, 16 Jan 2010 23:26:34 +0100, Falk Willberg
>> <(E-Mail Removed)> wrote:
>
>...
>
>>> The manual
>>> of my car (Peugeot Diesel, 2000 model) recommends to start the engine
>>> and immediatly drive at low RPM. Even the very simple engine of my
>>> motorcycle[0] does not require any warm up.
>>
>> You probably believe you can go 10000 miles on an oil change too.
>
>No, it's about 12000 miles (20000km) maybe only 9000 (15000km). And I
>use the cheapest oil I can get, that meets the specification. I never
>had an engine breakdown in 25 yrs.

You're a fool.

>As this thread is OT now, EOD for me.

Bye.