building a 240v thermostat for egg incubator

Discussion in 'The Projects Forum' started by gozitano, Feb 11, 2011.

  1. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    I wish to build a 240 volt thermostat for an egg incubator
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    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.
     
  3. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    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.
     
  4. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    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?).
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    Does the temperature need to be adjustable? If not, what temperature do you need?
     
  6. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,869
    1,393
    The optimum temperature for forced air chicken egg incubators is 99.5° F.
     
  7. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    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.
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    So, it must have some sort of power adaptor on board, like a transformer maybe?
     
  9. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    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.
     
  10. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
    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?
     
  11. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    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.
     
  12. wayneh

    Expert

    Sep 9, 2010
    12,100
    3,034
  13. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    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.
     
  14. debe

    Well-Known Member

    Sep 21, 2010
    946
    184
    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.
     
  15. gozitano

    Thread Starter New Member

    Feb 11, 2011
    8
    0
    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.
     
Loading...