Jump to content
Electronics-Lab.com Community
Sign in to follow this  
mphotis

temp sensor cooling system

Recommended Posts

Hi there,

ive been assigned a very interesting project. I need to design a cooling system for a go-cart using CO2 cooling.

Im thinking of using an LM355 temp sensor to sense the temperature on the motor. when the temperature on the motor reaches a certain threshold level, i want a transistor (or something else) to switch on causing a solenoid on the CO2 bottle to open the valve releasing CO2 through nozzles into the engine.

Im quite useless as regards my circuit design. Does anyone have any ideas on how i could maybe connect the transistor to the output of the sensor and calibrate it to switch at a threshold temperature.

thanks alot
Mike ???

Share this post


Link to post
Share on other sites

The tests have been done in the lab. No harm comes to the motor, as long as the CO2 is sent down the right airgap. Besides, the CO2 is only supposed to be turned on once the motor gets too hot...so it doesnt freeze.....once the temp is back down to a safe temperature the CO2 switches off....so any ideas??

Share this post


Link to post
Share on other sites

Mphotis,

I suppose it must be a controlled burst and at a specific temperature? There are some factors to consider, temperature, pressure, time and volume. Do you have any documentation on the tests?

Ante ::)

Share this post


Link to post
Share on other sites

Have you considered using the LM34? It's already calibrated in degrees Fahrenheit. I'm from the states, so I prefer the English units. ;)

It seems you could just use a simple comparator circuit.

The following document has a lot of specs and some good application examples. See their example of the "Simple Fan Controller". I think it is similar to your needs.

http://www.national.com/appinfo/tempsensors/files/temphb.pdf

If you have to put the sensor in a hostile environment, you may want to put the IC inside a metal tube. I've noticed that the plastic package fits neatly into a piece of copper tubing (the kind you hook up to your refrigerator's ice maker). Copper is quite malleable, so you can just pinch the end with a pair of pliers to seal it. Copper is also an excellent thermal conductor, so you should get a nice response time.

Good luck.

Darrin

Share this post


Link to post
Share on other sites

I just remembered that these temperature IC's have an upper range of about 300 deg Fahrenheit (about 150 deg C). This is probably good enough for your project, but just another thing to keep in mind. I think a typical automobile will overheat at about 240 deg F, but that's a water cooled engine. Is it possible that go-cart temperatures (I'm presuming air-cooled) will be much hotter?

Good luck with your project. I'm a mechanical guy myself, so I'll be interested in your results.

Darrin

Share this post


Link to post
Share on other sites

Presuming you are monitoring the cylinder head temp, you will need a thermocouple or RTD for these temperatures.
Sparkplug mtg one here
http://www.performancetrends.com/DatamiteTemperaturePictures.htm

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...