12 volt automotive fan speed controller

Discussion in 'Electronic Design' started by mark krawczuk, Nov 25, 2007.

  1. 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 krawczuk, Nov 25, 2007
    #1
  2. mark krawczuk

    Guest

    On Nov 24, 9:14 pm, "mark krawczuk" <> 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?
    , Nov 25, 2007
    #2
  3. 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



    <> wrote in message
    news:...
    > On Nov 24, 9:14 pm, "mark krawczuk" <> 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?
    >
    mark krawczuk, Nov 25, 2007
    #3
  4. mark krawczuk

    Guest

    On Nov 25, 5:44 am, "mark krawczuk" <> 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
    >
    > <> wrote in message
    >
    > news:...
    >
    >
    >
    > > On Nov 24, 9:14 pm, "mark krawczuk" <> 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.
    , Nov 25, 2007
    #4
  5. mark krawczuk

    Jim Thompson Guest

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

    >On Nov 25, 5:44 am, "mark krawczuk" <> 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 Voice:(480)460-2350 | |
    | E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
    | http://www.analog-innovations.com | 1962 |

    America: Land of the Free, Because of the Brave
    Jim Thompson, Nov 25, 2007
    #5
  6. mark krawczuk

    Guest

    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), wrote:
    > >On Nov 25, 5:44 am, "mark krawczuk" <> 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 Voice:(480)460-2350 | |
    > | E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
    > | http://www.analog-innovations.com | 1962 |
    >
    > America: Land of the Free, Because of the Brave


    So where is your schematic?
    , Nov 27, 2007
    #6
  7. mark krawczuk

    Jim Thompson Guest

    On Mon, 26 Nov 2007 19:15:51 -0800 (PST), 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), wrote:
    >> >On Nov 25, 5:44 am, "mark krawczuk" <> 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 Voice:(480)460-2350 | |
    >> | E-mail Address at Website Fax:(480)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 Voice:(480)460-2350 | |
    | E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
    | http://www.analog-innovations.com | 1962 |

    America: Land of the Free, Because of the Brave
    Jim Thompson, Nov 27, 2007
    #7

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