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Thermal Switch

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tehjrow

New Member
So i'm pondering a project that's basically gonna be a small water heater. However it needs to measure the temp of the water and turn on/off based on it's temp. The water needs to stay between 100F and 110F. Is there a switch that will be able to be IN the water and measure the temp?
 

Boncuk

New Member
Basically you can use any kind of temperature sensor (NTSc, PTCs and ICs)for that purpose.

To make it waterproof you might encapsule it with a chemistry glass or a copper pipe sealed with solder at the bottom and silcone on top (not dunk in water).

In case the sensor malfunctions it is easier to remove the silicone and replace the sensor.

A temperature controlled circuit for US$ 98 seems highly overprized to me.

Boncuk
 

MikeMl

Well-Known Member
Most Helpful Member
Do you want to build your own temperature controller?
If so, do you want to start from a commercial sensorlike this?
How are you heating the vessel with the water?
How many Watts? Volts?
 

tehjrow

New Member
How are you heating the vessel with the water?
How many Watts? Volts?
Honestly haven't gotten that far yet. Just thought about this today. Figured the temp sensor/switch would be the most difficult part so I started there.
 

MikeMl

Well-Known Member
Most Helpful Member
I would start with the Thermodynamics;)

It takes a lot of watts to heat a little bit of water. For example, the wife's electric tea pot has a 1500W heater. My Mr Coffee is like 1200W, and that only makes 4 cups.

Electric house water heaters are typically 5 to 10KW. Knowing the quantity of water and how rapidly you need to heat it will go a long way to defining your project.
 

Boncuk

New Member
I would start with the Thermodynamics;)

It takes a lot of watts to heat a little bit of water. For example, the wife's electric tea pot has a 1500W heater. My Mr Coffee is like 1200W, and that only makes 4 cups.
As far as I can see he just wants to heat a small amount of water to temperatures between 100deg/F (37.7deg/C) and 110deg/F (43.3deg/C).

It won't require hight wattage for such a temperature.

Making tea almost boiling water is required. (about 60deg/C to go)

Boncuk
 

AlainB

Member
Hi,

You could consider an aquarium water heater. They are not very expensive and available from 7.5 to 300 watts and maybe more. All is there for what you need except that the maximum temp. do not exceed 93F on the ones I saw. Maybe with a little tweaking....!

Aquarium Heaters

( Around here, a typical domestic electric water heater would be 3 or 4.5kW )

Alain
 
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