| View previous topic :: View next topic |
| Author |
Message |
mark krawczuk
Guest
|
 Posted: Sun Nov 25, 2007 11:25 am Post subject: 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 |
|
| |
|
 Back to top |
Eric Sears
Guest
|
| Posted: Wed Nov 28, 2007 3:57 am Post subject: Re: 12 volt automotive fan speed controller |
|
|
On Sun, 25 Nov 2007 15:43:20 +1030, "mark krawczuk"
<krawczuk@adam.com.au> wrote:
[quote]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
Just a thought - why not Google "DC speed control circuit"?[/quote]
I have found many circuits that way.
There are many of what you are looking for that use a 555 timer and a
20+amp FET - but I see no reason why the MJ darlingtons you mention
could not be made to work. I use the Dick Smith circuit (which used to
be found in the back of the annual catalogue) - I think both the Aus
and NZ catalogues were much the same.
There are some other circuits which use an op amp as a comparator, but
all are based on a variable ratio on/off switching.
Best wishes with finding what you want.
Eric Sears. |
|
| |
|
| Back to top |
|
