To power the incubator we need a reliable inexpensive power supply to energise the thermostat and heat source.
For the thermostat/incubator to work an adaptor is needed to change the 240 volt AC mains supply to a 12 volt DC (Direct Current) output.
In my view the easiest and simplest way is to power the heat source (bulb) and thermostat with the same 12 volt power supply is make two circuits.
That means running two simple circuits, one to power the incubator and one to power the bulb or heat source.
If your powering both the bulb and thermostat by the one transformer (the cheapest way) it is essential the adaptor provides enough amps to power both components.
If you run a larger incubator, you will need a larger heat source so an increased rated adaptor would be required. Perhaps a 3000ma (3 amp) rates supply.
Usually 1000ma (1 amp) or more will be required to power a small 10 watt bulb and the thermostat like the incubator I designed.
There are other means to supply 12 volts DC, but I found this to be the easiest!!