Date:         Tue, 27 Apr 2010 20:48:38 -0400
Reply-To:     Ken Lewis <kdlewis@NORTHSTATE.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Ken Lewis <kdlewis@NORTHSTATE.NET>
Subject:      Re: PWM controller ,
              was Water Cooler System Design Flaw Workaround?
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
              reply-type=original

Here is a company that does radiator fan control that I have been looking at
for our F-250: http://www.dccontrol.com/introf0.htm


----- Original Message -----
From: "Tom Hargrave" <thargrav@HIWAAY.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, April 25, 2010 12:06 PM
Subject: Re: [VANAGON] PWM controller , was Water Cooler System Design Flaw
Workaround?


>I just found the schematic on line and they are already using engine
> temperature to control the fan. I thought they would since VW is a
> excellent
> company.
>
> This being the case, something may be worth designing that turned on the
> fan
> earlier based on temperature change, like for example when pulling a hill,
> to give the cooling system a jump start on cooling.
>
> Tom
> www.towercooler.com
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of
> Mike "Rocket J Squirrel"
> Sent: Sunday, April 25, 2010 10:18 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: PWM controller , was Water Cooler System Design Flaw
> Workaround?
>
> Alistair Bell wrote:
>> my rad fan is 450 W if that helps
>>
>> alistair
>>
>> PS i dont see the point in a pwm controlled fan, I would concentrate
>> in a more sophisticated temperature interpretation, ie a PID
>> controller... monitor rate of temp change to that fan can keep on top
>> of things...
>>
>> but you know, my experience of the fans in real life is that they come
>> on, cool the van down and go off.... seem to work fine :)
>
> I'm with the Bell on this one. The radiator on the fan is capable of
> creating lots of cool water, and the thermostat opens and closes as needed
> to draw from that reservoir. If the engine was seeing huge over and
> undershoots in temperature then a better control system would be
> warranted.
> But the large thermal mass of the engine pretty much assures that temp
> changes will occur pretty slowly, and the thermostat seems capable of
> keeping up with them.
>
> I guess I don't see a problem that needs solving. But I do enjoy fancy
> engineering for engineering's sake, too.
>
>
> --
> Mike "Rocket J Squirrel" Elliott
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Westrailia: (Ladybug Trailer company, San Juan Capistrano, Calif.)
> Bend,
> OR KG6RCR
>