I wish to build a 240 volt thermostat for an egg incubator

 

Here is a discussion of a project - http://davesgarden.com/community/forums/t/571377/

The thermostat will only switch low voltage and current, but that won't prevent it from powering a relay that can in turn switch a larger one that can handle the current.

If this is a bit vague, so are your requirements.

 

Thank you for your input.Being more specific,I wish to build or find a simple thermostat circuit which could handle a two dozen chicken egg incubator .the incubator will use an electric globe as a heat source and will have a 12 volt fan for air circulation.Preferably no relay in the circuit.

 

Thank you for your input.Being more specific,I wish to build or find a simple thermostat circuit which could handle a two dozen chicken egg incubator .the incubator will use an electric globe as a heat source and will have a 12 volt fan for air circulation.Preferably no relay in the circuit.

No relay? I assume you are concerned about the mechanical life? There is such a thing as a solid state relay, which I think could be useful here.

What power is available (240v AC?), and what do your loads need? You mention a 12v fan (AC or DC?) and the heat globe (voltage, wattage?).

 

Does the temperature need to be adjustable? If not, what temperature do you need?

 

Does the temperature need to be adjustable? If not, what temperature do you need?

The optimum temperature for forced air chicken egg incubators is 99.5° F.

 

Hi Thank you for your input.
I have in the past used a 240v dimming thermostat and this is what I would like to build if possible.A dimming thermostat keeps a stable temp,moreso than one with a relay which keeps cutting in and out,dropping a degree or two in the process.Required temp.is 38.5 degrees C ,adjustable.
MY incubator is capable of holding 24 chicken eggs,has a centre well for water(humidity) and is powered by a 240v 60w halogen light.It has a 12 v fan for air circulation and egg turning is done manually.

 

It has a 12 v fan for air circulation and egg turning is done manually.

So, it must have some sort of power adaptor on board, like a transformer maybe?

 

Hi Wayneh,
Thanks for your interest.Well ,it it needs be that a small transformer is used so be it . However, last year I was using a 240v ac incubator circuit which was very simple.It was a wesfan circuit and it worked on straight 240v ac current.All it had on board was six components.The chip (ca3059) seemed to be doing all the work.

 

Hi Wayneh,
Thanks for your interest.Well ,it it needs be that a small transformer is used so be it . However, last year I was using a 240v ac incubator circuit which was very simple.It was a wesfan circuit and it worked on straight 240v ac current.All it had on board was six components.The chip (ca3059) seemed to be doing all the work.

Interesting IC - it sounds like a good choice for this application. Do you just need an application circuit example, or is there a reason you're not just using that circuit that you've used before?

 

Hi Wayneh,
Thanks for your reply. I cannot get the CA3059 locally and to get it from Asia ,where it is readily available,the cost is something like 10 times the cost of the chip.

 

Hi Wayneh,
Thanks for your reply. I cannot get the CA3059 locally and to get it from Asia ,where it is readily available,the cost is something like 10 times the cost of the chip.

Where are you? I see many sources after a quick Google search. For example: http://store.americanmicrosemiconductor.com/ca3059.html?gclid=CI727vnEiqcCFQTrKgodXySGdw

 

Hi Wayneh,
I am in West australia.The ca3059 is not available here. I have tried a number of places in the states and in China but with the same result.. they all ask exorbitant prices for postage.

 

Hi Gozitano, since your in Aus, why not try a Tempmaster Mk2, designed by silicon chip & av as a kit from Jaycar. I have found it keeps about 1to2deg cutin/out. I use it as a Fridge thermostat, but it can be used for higher temps.

 

Hi Wayneh,
The reason I am not using the old 240v thermostat circuit is because It seems that the IC (CA3059) appears to be gone.I changed all the other components on the circuit with no result and all that remains is changing the IC. It is not available here in Australia and to get one from overseas the cost is rather exhorbitant.