12 volt automotive fan speed controller

hi, i am after a basic type schematic to controll the speed of a 12 volt
dc automotive cabin fan .

seems to be a bit of a problem in these saab`s.

any schematic using a mj11032 or mj11016 darlington would be good. if
not any electronic speed controll schematic will be fine.
the original darlington is rated at about 25 amp , seems a bit excessive....
these darlingtons i have are rated at 30 and 50 amp.

thanks, mark k

On Nov 24, 9:14 pm, "mark krawczuk" <krawc...@adam.com.au> wrote:
> hi, i am after a basic type schematic to controll the speed of a 12 volt
> dc automotive cabin fan .
>
> seems to be a bit of a problem in these saab`s.
>
> any schematic using a mj11032 or mj11016 darlington would be good. if
> not any electronic speed controll schematic will be fine.
> the original darlington is rated at about 25 amp , seems a bit excessive....
> these darlingtons i have are rated at 30 and 50 amp.
>
> thanks, mark k

Mark,

How do you want to control the speed of your fan? Is it based off of
cabin heat? a user? something else?

hi, sorry , i suppose i should have said, i just need a potentiometer to
control the speed , it doesnt need to be controlled by cabin heat
etc...., the fan controller in my car isnt working and they havea tendency
to fail , so i am trying to construct a bit more robust one . everything
is working fine the heat , aircon , its just that the factory controller
is broken and the fan always stays on really low,.

thanks,
mark k



<(E-Mail Removed)> wrote in message
news:81fc40b7-7b49-47c2-ac00-(E-Mail Removed)...
> On Nov 24, 9:14 pm, "mark krawczuk" <krawc...@adam.com.au> wrote:
>> hi, i am after a basic type schematic to controll the speed of a 12
>> volt
>> dc automotive cabin fan .
>>
>> seems to be a bit of a problem in these saab`s.
>>
>> any schematic using a mj11032 or mj11016 darlington would be good.
>> if
>> not any electronic speed controll schematic will be fine.
>> the original darlington is rated at about 25 amp , seems a bit
>> excessive....
>> these darlingtons i have are rated at 30 and 50 amp.
>>
>> thanks, mark k
>
> Mark,
>
> How do you want to control the speed of your fan? Is it based off of
> cabin heat? a user? something else?
>

On Nov 25, 5:44 am, "mark krawczuk" <krawc...@adam.com.au> wrote:
> hi, sorry , i suppose i should have said, i just need a potentiometer to
> control the speed , it doesnt need to be controlled by cabin heat
> etc...., the fan controller in my car isnt working and they havea tendency
> to fail , so i am trying to construct a bit more robust one . everything
> is working fine the heat , aircon , its just that the factory controller
> is broken and the fan always stays on really low,.
>
> thanks,
> mark k
>
> <gregmh...@gmail.com> wrote in message
>
> news:81fc40b7-7b49-47c2-ac00-(E-Mail Removed)...
>
>
>
> > On Nov 24, 9:14 pm, "mark krawczuk" <krawc...@adam.com.au> wrote:
> >> hi, i am after a basic type schematic to controll the speed of a 12
> >> volt
> >> dc automotive cabin fan .
>
> >> seems to be a bit of a problem in these saab`s.
>
> >> any schematic using a mj11032 or mj11016 darlington would be good.
> >> if
> >> not any electronic speed controll schematic will be fine.
> >> the original darlington is rated at about 25 amp , seems a bit
> >> excessive....
> >> these darlingtons i have are rated at 30 and 50 amp.
>
> >> thanks, mark k
>
> > Mark,
>
> > How do you want to control the speed of your fan? Is it based off of
> > cabin heat? a user? something else?- Hide quoted text -
>
> - Show quoted text -

Sorry, I don't have a schematic for you, just a couple of ideas and
pointers. 25 amps is NOT overkill by any means as most heater blowers
will pull that much easily. So I would not use your 30 amp darlington
and would only feel good about your 50 IF it had a real good heat sink
arrangement.

Most auto heater blowers use wind cooled wire wound resistors in
series with the blower motor circuit to attain low and medium speeds
with high speed being a direct connection to 12+ volts. Some
regulatory body specifies that a super low speed is mandated to be on
all the time to guard against carbon monoxide poisoning, which is
probably the low speed you've noticed.

What typically happens is the connection between the standard copper
based slip on connectors corrodes with the ni-chrome wire of the wire
wound resistors in the fan speed circuits. Silver soldering the
connections maybe an easier solution?

If I were to build a circuit for your application I would use UA78s40
switching IC to drive the darlington that would drive a torroid step
down/step up circuit. Switching in different resistors in the
voltage feedback circuit would then select fan speeds. And in my old
Subaru for example, I also need to hit the fan motor with some 16-17
volts in order to have me a super high speed for those really cold
winter days.

On Sun, 25 Nov 2007 14:29:54 -0800 (PST), (E-Mail Removed) wrote:

>On Nov 25, 5:44 am, "mark krawczuk" <krawc...@adam.com.au> wrote:
>> hi, sorry , i suppose i should have said, i just need a potentiometer to
>> control the speed , it doesnt need to be controlled by cabin heat
>> etc...., the fan controller in my car isnt working and they havea tendency
>> to fail , so i am trying to construct a bit more robust one . everything
>> is working fine the heat , aircon , its just that the factory controller
>> is broken and the fan always stays on really low,.
>>
>> thanks,
>> mark k
>>
[snip]
>

>Most

CHEAP

>auto heater blowers use wind cooled wire wound resistors in
>series with the blower motor circuit to attain low and medium speeds
>with high speed being a direct connection to 12+ volts. Some
>regulatory body specifies that a super low speed is mandated to be on
>all the time to guard against carbon monoxide poisoning, which is
>probably the low speed you've noticed.
>
[snip]

The controller design I did for Bosch (Bühlertal, Germany) for
inclusion in the Mercedes AC/heat system was a 3-phase electronically
commutated motor... custom microchip plus 3 N-channel MOSFET's...
continuously variable speed, but controlled acceleration (so that the
chief engineer couldn't hear any whine when he stuck his head in the
air duct ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

On Nov 25, 4:03 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@My-
Web-Site.com> wrote:
> On Sun, 25 Nov 2007 14:29:54 -0800 (PST), mel...@my-deja.com wrote:
> >On Nov 25, 5:44 am, "mark krawczuk" <krawc...@adam.com.au> wrote:
> >> hi, sorry , i suppose i should have said, i just need a potentiometerto
> >> control the speed , it doesnt need to be controlled by cabin heat
> >> etc...., the fan controller in my car isnt working and they havea tendency
> >> to fail , so i am trying to construct a bit more robust one . everything
> >> is working fine the heat , aircon , its just that the factory controller
> >> is broken and the fan always stays on really low,.
>
> >> thanks,
> >> mark k
>
> [snip]
>
> >Most
>
> CHEAP
>
> >auto heater blowers use wind cooled wire wound resistors in
> >series with the blower motor circuit to attain low and medium speeds
> >with high speed being a direct connection to 12+ volts. Some
> >regulatory body specifies that a super low speed is mandated to be on
> >all the time to guard against carbon monoxide poisoning, which is
> >probably the low speed you've noticed.
>
> [snip]
>
> The controller design I did for Bosch (Bühlertal, Germany) for
> inclusion in the Mercedes AC/heat system was a 3-phase electronically
> commutated motor... custom microchip plus 3 N-channel MOSFET's...
> continuously variable speed, but controlled acceleration (so that the
> chief engineer couldn't hear any whine when he stuck his head in the
> air duct ;-)
>
> ...Jim Thompson
> --
> | James E.Thompson, P.E. | mens |
> | Analog Innovations, Inc. | et |
> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
> | Phoenix, Arizona Voice480)460-2350 | |
> | E-mail Address at Website Fax480)460-2142 | Brass Rat |
> | http://www.analog-innovations.com | 1962 |
>
> America: Land of the Free, Because of the Brave

So where is your schematic?

On Mon, 26 Nov 2007 19:15:51 -0800 (PST), (E-Mail Removed) wrote:

>On Nov 25, 4:03 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@My-
>Web-Site.com> wrote:
>> On Sun, 25 Nov 2007 14:29:54 -0800 (PST), mel...@my-deja.com wrote:
>> >On Nov 25, 5:44 am, "mark krawczuk" <krawc...@adam.com.au> wrote:
>> >> hi, sorry , i suppose i should have said, i just need a potentiometer to
>> >> control the speed , it doesnt need to be controlled by cabin heat
>> >> etc...., the fan controller in my car isnt working and they havea tendency
>> >> to fail , so i am trying to construct a bit more robust one . everything
>> >> is working fine the heat , aircon , its just that the factory controller
>> >> is broken and the fan always stays on really low,.
>>
>> >> thanks,
>> >> mark k
>>
>> [snip]
>>
>> >Most
>>
>> CHEAP
>>
>> >auto heater blowers use wind cooled wire wound resistors in
>> >series with the blower motor circuit to attain low and medium speeds
>> >with high speed being a direct connection to 12+ volts. Some
>> >regulatory body specifies that a super low speed is mandated to be on
>> >all the time to guard against carbon monoxide poisoning, which is
>> >probably the low speed you've noticed.
>>
>> [snip]
>>
>> The controller design I did for Bosch (Bühlertal, Germany) for
>> inclusion in the Mercedes AC/heat system was a 3-phase electronically
>> commutated motor... custom microchip plus 3 N-channel MOSFET's...
>> continuously variable speed, but controlled acceleration (so that the
>> chief engineer couldn't hear any whine when he stuck his head in the
>> air duct ;-)
>>
>> ...Jim Thompson
>> --
>> | James E.Thompson, P.E. | mens |
>> | Analog Innovations, Inc. | et |
>> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
>> | Phoenix, Arizona Voice480)460-2350 | |
>> | E-mail Address at Website Fax480)460-2142 | Brass Rat |
>> | http://www.analog-innovations.com | 1962 |
>>
>> America: Land of the Free, Because of the Brave
>
>So where is your schematic?

It predates CAD, is pencil on D-sized.

I'll see if I can scan a reasonable copy.

Keep in mind, it's a CHIP... thus HUNDREDS of transistors.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave