kiln controller

damion

Hello all,

The digital controller for my kiln just died on me. I would like to find a way to bring the kiln up to about 1100 degrees F and·sustain that temp. Basically I need to make a thermostat. I have a few bs2p's and·the 40 amp relay for running the kiln.·Does anyone have any advice? Also is it possible to monitor temps that high using a ds1620 temp·sensor? Thanks...
Damion·

Franklin

You will probably need to use a thermocouple. Parallax sells one I believe. There is a thread in the completed projects on a solder pot controller that may be similar enough to modify for your use.

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- Stephen

LoopyByteloose

You can either measure directly with a traditional bi-metallic thermocouple and may already have the wire to make sensors, or you can use a solid-state sensor from afar to look into the kiln.

In the first case, you just have to use an ADC to convert voltages to digital for the BasicStamp to display. In the second case, some devices come with an ADC included and some do not. You would have to read the documentation to verify the appropriate range and use.

In general, the traditional sensor is what wears out due to the extreme heat. You digital unit might be just fine.The DS1620 is way too low.

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PLEASE CONSIDER the following:

Do you want a quickly operational black box solution or the knowledge included therein?······

···················· Tropically,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

Post Edited (Kramer) : 2/9/2008 9:50:53 AM GMT

damion

Thanks for the responses guys.

Kramer are saying that it is probably the thermocouple in the kiln that went out and that the digital controller is fine? Because now that I think about it that certainly appears the case. The controller still works but it reads 0000 for the temp and doesn't cycle.

D

LoopyByteloose

Yes.

Even though we have greatly advanced in digital technology in the past few decades, any temperature measurement in the extremes of a kiln or furnace is usually dependent on an older technology of a bi-metalic junction that creates a voltage that has a linear relationship with temperature.

The junction is actually created by welding two dis-simlar wires together. You can buy new ones if they break [noparse][[/noparse]and they do] or you can run a high enough voltage through the sensor to allow you to electro-weld your own repair. Then you can recalibrate.

Thermocouple Types are various metallic alloys for different temperature ranges. You just have to determine which is designed for your unit and replace it. Industrial thermocouple types: J, K, T, E, N, R, S, B are available.

Also Google around and study the basics. There are web sites that mention DIY welding and repair of damaged units as some vendors are adding huge mark ups to what is essentially a generic sensor.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
PLEASE CONSIDER the following:

Do you want a quickly operational black box solution or the knowledge included therein?······

···················· Tropically,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

Post Edited (Kramer) : 2/12/2008 4:50:02 AM GMT