Electric fan soft start circuit?

[myclone]

First off if this is in the wrong section feel free to move it.



I remember seeing a post/advertisement on here a while back where someone was selling a nice/adjustable "soft start" system for engine cooling fans but for the life of me I cant find it now (yes, I did multiple searches).

Can someone post a link or the company thats making them? TIA

[69HuggrrrPT]

Could it be the http://www.dccontrol.com/ cotroller you are lookin for? This is the one I am using, basically it slowly "ramps" fan speed up & down, not just on & off. I have mine hooked up to a Mark VIII fan, works good. If this is what you are looking for contact Gmachinz from this site.

HTH

[myclone]

Could it be the http://www.dccontrol.com/ cotroller you are lookin for? This is the one I am using, basically it slowly "ramps" fan speed up & down, not just on & off. I have mine hooked up to a Mark VIII fan, works good. If this is what you are looking for contact Gmachinz from this site.

HTH

Yep, thats the one. Thanks for the help .

[dhardison]

Dean, Will the DC Control controller allow you to use a stock alternator with the Mark VIII since it slowly ramps the fan up/down?

Thanks,
Dan

[69HuggrrrPT]

Dan,

Although it dosen't hurt to upgrade your alternator, I was told you can use your current one due to the fact that the controller does not require alot of voltage.
It is wired direct to the battey and not the charge post of the alternator. With that said I went with a CS alternator at the same time I changed my fan setup.

[GT350Clone]

FWIW, I just installed one of the new Spal FAN-PWM adjustable controllers, you can adjust both low (50%) & high (100%) speed independently, as well as controlling multiple fans. An A/C input is included as well.

The thing I liked best was that it hooks up to your existing temperature sending unit, instead of requiring an additional bung/sender.

Mine came from www.streetortrack.com. It's so new that they may not have it on the webpage yet.

[gmachinz]

The new Spal system looks nice, too. The main difference is that the DC Controller constantly varies fan speed to changing coolant conditions which is nice and, it allows for temp. changes with under-drive pulleys, AC usage and jumpers for lowering or raising the set-points at which the fan will kick on-sort of a band-aid for those with inadequate radiators/cooling fan designs. Also, you have to have an electric fan capable of cooling anything to take full advantage of any aftermarket controller-that's what makes the Mark VIII fan so attractive-it's just the best imo. -Jabin

[marolf101x]

hello, my name is Britt and myself and another guy at SPAL designed the FAN-PWM.

I'd like to clarify a few things:

First let me say that the DC Control fan controller is a nice unit. If I didn't build the FAN-PWM I would use the DC Control unit.

The SPAL controller will vary the speed of the fan based on engine temperature. It uses Pulse Width Modulation (hence the pwm in the name) just like the DC Control unit. It can take temp readings from the OEM fuel injection sensor, the OEM temp gauge sensor, or the SPAL sensor. It allows the user to choose a Low and High setting. The Low starts the fan spinning at 50%, and it will increase in speed until it reaches the High setting, at which time the fan is running full speed and a negative output is given to trigger a relay for a secondary fan (or terciary, or as many fans as you want to run).

I also has an A/C input that can be connected to a trinary switch (to control the fan(s) based on A/C system pressure) or connected to the A/C compressor. This input could also be used as a manual override so the user can turn the fan(s) on whenever he/she likes regardless of if the vehicle is running or not. (this feature is nice for people who have an electric water pump. It alows the fan(s) and water pump to be turned on when the vehicle is not running, circulating the coolant and lowering water temperature.)

We also placed the unit in an extruded aluminum case that dissipates heat and is waterproof so it can be mounted in the engine compartment.

If you have any questions, concerns, etc. Please feel free to drop me an e-mail.

-Britt-

[gmachinz]

Sounds interesting. So, it really doesn't ramp speed up/down instantly-it more or less reads a range at which it triggers a relay, then? How much cost are we looking at here? The Mark VIII's rarely need to run even as high as 50% fan speed though. What is the expected amp draw at 50% if that is the minimum speed the fan will run once engaged?-Jabin

[baskin]

hello, my name is Britt and myself and another guy at SPAL designed the FAN-PWM.
I'd like to clarify a few things:
First let me say that the DC Control fan controller is a nice unit. If I didn't build the FAN-PWM I would use the DC Control unit.
The SPAL controller will vary the speed of the fan based on engine temperature. It uses Pulse Width Modulation (hence the pwm in the name) just like the DC Control unit. It can take temp readings from the OEM fuel injection sensor, the OEM temp gauge sensor, or the SPAL sensor. It allows the user to choose a Low and High setting. The Low starts the fan spinning at 50%, and it will increase in speed until it reaches the High setting, at which time the fan is running full speed and a negative output is given to trigger a relay for a secondary fan (or terciary, or as many fans as you want to run).
I also has an A/C input that can be connected to a trinary switch (to control the fan(s) based on A/C system pressure) or connected to the A/C compressor. This input could also be used as a manual override so the user can turn the fan(s) on whenever he/she likes regardless of if the vehicle is running or not. (this feature is nice for people who have an electric water pump. It alows the fan(s) and water pump to be turned on when the vehicle is not running, circulating the coolant and lowering water temperature.)
We also placed the unit in an extruded aluminum case that dissipates heat and is waterproof so it can be mounted in the engine compartment.
If you have any questions, concerns, etc. Please feel free to drop me an e-mail.
-Britt-

When you say vary the speed do you mean that it will either run the fan at low or high speed, or that it actually varies the speed infinitely from full off to full on? If it’s the prior, than the two units aren’t quite the same.

With regard to reading off of the temperature sending unit, the sending units degrade. So, when it does degrade, the fan will begin to turn on at 20, 30, 40 degrees higher in temperature. The car owner then looks at the gauge and sees that everything is “correct”. It may very well save costs, but what is given up in that savings is the real purpose of the gauge, and that’s to evaluate the cooling system independent of its components.

The low and high speed setting buttons are clever, but if you end up with a dead battery, will the temperatures programmed into the unit keep? Most people like to deal with one problem at a time, a dead battery is frustrating enough without having to look for directions in order to reconfigure a fan controller. It’s not that it would be difficult to do, but it would arguably be the least convenient time to deal with it.

I see applications for everything from door locks to ventilation fans but don’t see any patents regarding pwms granted or pending at the uspto. Is this a unique Spal design?.

[baskin]

5,910,743 7,006,762

www.uspto.gov

[gmachinz]

I see you got mY email about this, Brian-good. If you can, give me a call about it-I tried calling you today twice but my calls got dropped. -Jabin

[mikesz]

Anybody have one of these things hooked up with a decent car stereo? Do you get any interference?

Mike

[myclone]

Anybody have one of these things hooked up with a decent car stereo? Do you get any interference?

Mike

FWIW the reason I started this thread was that when I installed my own soft start pwm circuit the "ringing" of the power FET played havoc with the audio system from the RFI when the fan was ramping up/down. Being an electronics tech by trade I could have prolly fixed it with more design work but I was already at the point of having more time in it than it was worth by building my own rather than just buying an off the shelf unit.

Anyways maybe the SPAL unit isnt an issue but my home built circuit was noisey as hell electrically speaking.