Anyone seen a temperature controlled relay?

[johnnynine]

I found this but it is much more than I would want to spend, especially since I need two.

Ideally I'd link to use a quiet 12v 120mm fan that plugs into a simple relay that is controlled by the temperature in the cabinet.

Any ideas?

Thanks,
Johnny

 

[mdesmarais]

I used a regular old mercury bulb thermostat, and a 12v wall wart. Dirt cheap since they came out of my junk box. ;-)

 

[BraveSirRobbin]

Look for Winland thermostats on EBay. I found one for very cheap a while ago. Basically you set a low and high threshold and they offer contact closures when either is reached.

Maybe something like THIS. Just watch the contact ratings (voltage and current) for what you are trying to control.

 

[KenM]

I have used something like this before on a cooling fan. The bad part is that it is not adjustable. I never tried opening one up to see if it could be tweaked at all.

http://www.smarthome.com/7144.html

Ken

 

[rfdesq]

I'm not sure of your security or HA setup. I used an ELK temperature sensor combined with a cheap fan an ELKRB and some rules.

 

[drozwood90]

Go to http://www.digikey.com

Search for "thermal switch" (come on does anyone need to tell people to not put the quotes when they are "copying" something to an input box??)

Choose N/O or N/C, Style, Temperature limit.

They are bi-metal switches (like a "thermal relay").

--Dan

 

[Ranger Digital]

something like this would work. program to trigger an event in HA.

http://cgi.ebay.com/WINLAND-TA-1-MECHNICAL...VQQcmdZViewItem

 

[johnnynine]

Thanks guys.

The thermo cube on smarthome would be ideal but the temperature ranges they offer probably aren't optimal. I'd guess that I would want the fan to kick on around 100F .

The Winland thermostat might work if I could find a good deal.

Using an automation system is a little overkill for the project in my opinion, and I don't have sufficient wiring to the location anyways.

Although not the simplest solution, the bi-metal switches look like they are cheap and can carry the full 12v .5mA load so I could just wire the wallwart through it.

Thanks.

 

[brotsten]

ApogeeKits assembled $16 or Kit $9

Brian

 

[BraveSirRobbin]

ApogeeKits $16
Brian

Nice find Brian!

 

[johnnynine]

ApogeeKits assembled $16 or Kit $9

Brian

Interesting, could I use the same 12VDC transformer to power the thermostat AND the fan by running the power in parallel?

Edit: It looks like they actually have a wiring diagram showing this but with a siren, so it looks like the answer is yet.

 

[Steve]

It is a nifty little device, but it has 1 problem - a narrow temperature band (won't go to 100°F):

temperature range: 41°F to 86°F (5°C to 30°C)

Wow: I can typo even the simplest post!

 

[ginigma]

What about changing the thermister? I think that's the right terminology. You'd probably have to recalibrate it, but that shouldn't be an issue.

 

[johnnynine]

It is a nifty little device, but it has 1 problem - a narrow temperature band (won't go to 100°F):

temperature range: 41°F to 86°F (5°C to 30°C)

Right, at 86°F the fan would almost always be running considering TiVo and the set-top box are always running... In which case I would be better off just running a fan without a thermostat.

I think I'll do some temperature tests in the cabinet with the doors closed so I have a better idea of what to expect.

 

[brotsten]

It is a nifty little device, but it has 1 problem - a narrow temperature band (won't go to 100°F):

temperature range: 41°F to 86°F (5°C to 30°C)

Right, at 86°F the fan would almost always be running considering TiVo and the set-top box are always running... In which case I would be better off just running a fan without a thermostat.

I think I'll do some temperature tests in the cabinet with the doors closed so I have a better idea of what to expect.

Maybe you can get away mounting it low in the cabinet.

Brian