controlling fans via ambient tempature

[reefkeeper78]

Has anyone found a way to introduce an ambient tempature sensor into their light fixtures that can be used to increase/decrease cooling fans dependant on tempature.

I ask becuase I work on cars. These type of senors are on every singe model car in existence in the last 20ish years. They work on resistance or voltage drop across the sensor. An applied nominal voltage is then lost through resitance depening on tempature, the computer/controller uses this information to turn circuits on or modify engine performance.

Can someone explain to me how to set up a program to run a varied fan via temp or show me previous posts others have done? I can't seem to find any posts on the topic. In my mind I would use some sort of thermoresistor that will have 5 volts applied to one side and the other side of the thermoresistor will be the input signal to the controller. Thanks

 

[Gorgok]

I found this when i googled the topic: http://www.radiolocman.com/shem/schematics.html?di=47949

Seems like that is pretty much what you need. The soldering pic is pretty horrible (imo), but the schematic is good.

I may actually do this as well, i had planned on either powering my fans all the time or pwm them with my white lights... but really this is simpler and cooler.

 

[rwb500]

have you looked at PC equipment? theres probably a fan controller available that comes with a temperature sensor.

 

[atreis]

Computer case fan controllers:
http://www.xoxide.com/lian-li-tr-03-thermal-monitor-fan-control-blk.html
http://www.amazon.com/Computer-Speed-Control-Temperature-Controller/dp/B005HNK9S8

Or just a single fan with temp controller:
http://www.amazon.com/gp/product/B000234W0Y/ref=pd_lpo_k2_dp_sr_3?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B005HNK9S8&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=0ZZWY9BQC4Q3X1ANB2AK

 

[Gorgok]

The first one i think measures only the motherboard for temperature, then bases fan speed off of it. Without a motherboard i don't think it has much use.

The second doesn't seem to measure temperature at all, just has an array of potentiometers for manually slowing them down.

The third is essentially what the DIY option i listed is, except its set at a certain temperature and cannot be adjusted.

 

[rysher]

i have it using my controller, i had a thermometer attached to the LED's heatsink, the fan speed adjusts based on the tmeperature of the heatsink.

my controller is ReefAngel. it's capable to handle 3 thermometers.

 

[reefkeeper78]

thanks for the link gorgok, thats pretty much what I was looking for in a nut shell

rysher, which one are you running, is it one of the three other links posted?

 

[rysher]

reefangel.com

 

[doctorgori]

reefangel.com

+1 ....I was about to say the same thing (insert Apex or RKL tho)

I got these

and mounted them like this

and hooked them up to this (Apex Jr.)

Here is my temps (given the changes in ambient I think its pretty impressive)

13:00 11/06/2011 79.0 8.14 0.0
13:20 11/06/2011 79.1 8.15 0.0
13:40 11/06/2011 79.1 8.16 0.0
14:00 11/06/2011 79.2 8.17 0.0
14:20 11/06/2011 79.3 8.18 0.0
14:40 11/06/2011 79.3 8.18 0.0
15:00 11/06/2011 79.4 8.19 0.0
15:20 11/06/2011 79.5 8.20 0.0
15:40 11/06/2011 79.5 8.20 0.0
16:00 11/06/2011 79.6 8.20 0.0
16:20 11/06/2011 79.7 8.21 0.0
16:40 11/06/2011 79.7 8.21 0.0
17:00 11/06/2011 79.8 8.21 0.0

 

[rysher]

+1 ....I was about to say the same thing (insert Apex or RKL tho)

I got these

will the RKL or APEX be able to control the fan speed base on temperature or it's only on/off?

 

[doctorgori]

will the RKL or APEX be able to control the fan speed base on temperature or it's only on/off?

The Apex "Sr" has a variable speed port that used for powerheads and/or light dimming, but I'm, not familiar with any functionality beyond that....I own a Apex Jr ...
Still, and trust me, the 125-150bucks will be well spent....I'm partial to the Jr for the xtra $24 ...but either unit is hands down a better value than a single function heat controller

 

[frank2926]

Gori, what lights are you running?

I get the same temp swings with Halides and NO fans. I have them installed, just dont use them in the fall winter. No need.

This time of year it is more about keeping the temp warmer not cooling.

I think you would see an improvement if you pointed the fans more at the water surface. With an open top like that you should see much better results.

 

[doctorgori]

Gori, what lights are you running?

I get the same temp swings with Halides and NO fans. I have them installed, just dont use them in the fall winter. No need.

This time of year it is more about keeping the temp warmer not cooling.

I think you would see an improvement if you pointed the fans more at the water surface. With an open top like that you should see much better results.

Thats a ATI Sunpower above a 90G...yeah, you're right, I am sorta "whiffing" the fans above the water, so the evap effect is marginal but "measureable" ...(I couldn't hold it under 84F this past summer)
....but thats about all the evap I can deal with, heck I use about 5gal of RO in 4-6 days

...and yeah, I'm pretty sure my heater will kick in soon as my basement temps dip below my set threshold of 76ish ...but I got a new well insulated crib, the falls been warm so ambient in my basements been about 75