Maker Pro
Maker Pro

12 volt incubator circuit

clem

Sep 24, 2010
7
Joined
Sep 24, 2010
Messages
7
I need to build a 12 volt incubator circuit comprising a light globe as a heat source,a thermostat and a computer fan
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Great. Than sounds like something that would work.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Depending on the current ratings for the lamp and the thermostat, the fan and the lamp go in parallel and the thermostat is in series with them.
 

clem

Sep 24, 2010
7
Joined
Sep 24, 2010
Messages
7
clem

Hi Steve,
Many thanks for your prompt reply. I know very little about electronics.I can identify necessary components.I can follow a small circuit and do soldering
I was hoping to start with a 12 v plug in transformer rated at 1.5 amps.As for the thermostat I have no idea. I was hoping that someone could come up with a simple circuit that I could follow.???
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
What are you trying to make? 18W may be insufficient. What temperature are you looking at? with what tolerance?

I would be looking for a mechanical thermostat that covers the required temperature range.
 

clem

Sep 24, 2010
7
Joined
Sep 24, 2010
Messages
7
I am trying to make an incubator work on a 12v.supply.The heat source in the circuit (a 12v incandescent light) needs to be 25 watt plus to generate the required heat.The heat required is 100 degrees farenheit plus 1. I can buy the required mech. thermostat from the parts shop if same is available. All this being equal,can you possibly help me with a scetch for the circuit?
Many thanks Steve.
 

Militoy

Aug 24, 2010
180
Joined
Aug 24, 2010
Messages
180
I’ll assume you’re trying to hatch some kind of poultry or game birds in your incubator. Your fan setup needs to be tailored to the kind of eggs you are hatching. Some incubators use the fan for venting – to prevent overheating or condensation of moisture. Most though, just use the fan to circulate air to keep the temperature even throughout the box. Most eggs will need a source of moisture in the incubator – and the high humidity can cause problems with some open-frame thermostats. Ducks and other waterfowl need an especially humid environment, so a sealed thermostat is a good idea, if that’s in your plans.
For starters – you might consider using a 24 volt fan, or a very small 12 volt one – to keep airflow as gentle as possible. For a 25W 12V lamp – I would use a low-voltage RV (caravan) incandescent bulb. Ebay has them for sale right now from $1.35 to around $3.00 each.

Wiring is as Steve described it – Starting from the positive (red [+]) side of the input, wire through a fuse; to one side of the thermostat; out the other side of the thermostat; to the positive (+) side the fan, which should also be connected to one side of the lamp socket. The negative (-) side of the fan should be connected with the other side of the lamp socket, along with a wire connected to your negative (black [-]) input.

Make sure your incubator is ventilated; keep the eggs out of the water pan; mark one side of each egg with a pencil “x”, to help keep track when you periodically turn the eggs (critical). Keep a spare bulb handy, and an eye on the bulb in the incubator to make sure it hasn’t burned out. Good luck!
 

clem

Sep 24, 2010
7
Joined
Sep 24, 2010
Messages
7
Hi,
Thanks for your input.
I have tried to obtain a sealed thermostat that would do the job in question from two suppliers with no result.If only Can anyone help with a circuit to build a thermostat??
 

clem

Sep 24, 2010
7
Joined
Sep 24, 2010
Messages
7
Hi Steve,
I seem to be on the way to solving my incubator problems. I have salvaged a wafer switch from a portable oil heater.I have set it up and it does work.The only problem it drops 5 degrees before it switches back on.It has a sensor (thermistor?)in line.Can I possibly solve the problem by changing the latter ?
Many thanks.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
How accurately do you need the temperature maintained?

If the thermostat has no hysteresis the lamp will be turned on and off very frequently leading to early failure and loss of your eggs.

Varies by 5C or 5F? if the latter, then that's not too bad.
 

Militoy

Aug 24, 2010
180
Joined
Aug 24, 2010
Messages
180
5 degrees (F) is pretty good for hystersis. You should be able to keep the eggs in a narrower temp range by insulating the incubator well - and locating the t-stat near the vents. The small commercial units (Mother Hen brand, etc) have a body constructed entirely of polystyrene foam. I used a regular house heater t-stat when I built one for quail eggs, and was able to keep the eggs within about a 2-3 degrees F range - even in variable weather. That's as good as the brooding bird will do in a natural environment. BTW - Forgot to mention that you should place an accurate thermometer right among the eggs - and build your incubator with a small sight window, so you can monitor temp.
 

clem

Sep 24, 2010
7
Joined
Sep 24, 2010
Messages
7
Hi Steve,
I just read your last email.Yes,the thermostat was switching was switching back on after the loss of 5 degrees celsius.I was hoping that it would be possible to wire on some component in line to bring it closer to the one degree mark.
Many thanks.
Clem.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
Top