Temperature sensor + cooler

Hi.

I need to design one PCB that will be used for temperature monitoring on production machine.

Basically if should do just two simple tasks.

1.) if the temperature is to high --> start cooler ( vent 12V ) 2.) shutdown the main production machine

Is there some ready made stuff for this ? The most important is that i should be able to define temperature level.

GM

Reply to
gm
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On a sunny day (Thu, 12 Feb 2015 16:33:36 +0100) it happened gm wrote in :

No need for a peeseebee, use one or more 'klixons'.

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Reply to
Jan Panteltje

Ummm- not incredibly accurate and hysteresis is fairly huge. These are mainly for deenergizing circuits under faults and the seller describing the one as a thermostat is an idiot.

Reply to
bloggs.fredbloggs.fred

How do you need to set the temperature?

If you want to do 1 & 2 simultaneously, from a hand-set knob or whatever, a simple thermostat and a DPDT relay may do the job.

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www.wescottdesign.com
Reply to
Tim Wescott

------------------ I dont know temperature level but i guess that it should not go over 40 degrees Celsius. I was planning to set the temperature level directly on the place.

Reply to
gm

If you could pin it down to a specific temperature, you could use one of these to shut the machine off while it's too hot, and use a 120VAC (assuming the main machine runs off of 120V) input solid-state relay to switch 12V to your fan.

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Newark carries them.

Normally I'm the "oh you can get a 32-bit microcontroller for less than a buck, use that" guy on this group -- if _I_ think it should be done with a couple of simple bits that have been available for decades, then maybe that's the way to go?

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Tim Wescott 
Wescott Design Services 
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Reply to
Tim Wescott

You can buy temperature controllers which will do this "off the shelf". Omega is a well-known vendor of these.

I suspect that a standard Omega controller with an alarm output such as a CN743 could do this easily. You could set two different temperatures (a "setpoint" and an "alarm"). The controller would turn on the cooling (fan) as soon as the temperature rose to the specified setpoint. If the temperature rose to the upper alarm limit, the alarm output would go high and switch off the production machine.

Similar controllers are made by other companies. They all tend to fit one of various DIN-sized panel openings. They use various different (standard) types of thermocouple and can usually be set to 1-degree resolution, C o

Buy new, or buy eBay (I did the latter to make a solder reflow station out of an old toaster oven :-)

If this is for use in a business/production environment, buying a professionally-made, properly-tested design is probably prudent. If you build something yourself and it malfunctions and doesn't protect a worker from a fault in the production machine, Bad Things could result.

Reply to
Dave Platt

It sounds like you do not know much about this problem or the common ways to approach it. If you cannot define even the temperature you want how could we help.

It is such a simple and coomon problem that you must be way out of your depth. This NG is not a substiute for a grounding in the subject of elec design.

Sorry to be so harsh . But! :-?

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John G Sydney.
Reply to
John G

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