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Running a 220v heater element on 110v

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Dakogid

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So I am a total "small yellow bus" passenger when it comes to electronics so forgive the simplicity of my questions

I want to make an incubator for chicken eggs.

The heat souce should reach its peak heat fast but also cool fast so as to not create drastic swings in the air temperature. The ideal unit should be between 120 and 150 W on a 110v power.

Available to me is a PTC heating element heater that is rated at 250 wats and 220V. If I run it on 110V power, will it generate 125 watts?

cheers
 
Going from 220 to 110 has a double effect.
V=1/2
Also the current is 1/2.
A=1/2
Power is Voltage * Current.
Power in watts = 1/4.
Your power is 62 watts.
Is that enough heat?

At least you are not in a "yellow submarine".
 
Available to me is a PTC heating element heater that is rated at 250 wats and 220V. If I run it on 110V power, will it generate 125 watts?
PTC means "positive temperature coefficient", which means the resistance of the element increases as the temperature increases. This means that the above calculations will yield a lower than actual power value at your decreased voltage and hence power & temperature. The amount of error depends on the coefficient magnitude and the temperature of the element.
 
Is there any particular reason for using the ptc element? It might take some of the guesswork out of the calculation if you used a non-ptc type heating element (in conjunction with a thermostat).
 
Hello,

Measure the current when you first plug it in and then after several minutes of operation.

Many heating elements used for AC are inductive too, where the current may not be in phase with the voltage so the power calculation is a little more complicated:
P=I*E*cos(Theta)

where Theta is the angle of lead or lag between current and voltage.

If the inductance is constant then we may be able to apply a linear rule, and that is the most likely. The PTC adds a little extra complexity because if it does not get that hot then the power may be much higher than we calculate. So it could be as high as 125 watts, but it is so hard to say without some more testing.

The best bet is to try it in the application to see if it is able to maintain the proper temperature with the given external variables present such as ambient temperature swings.

This is almost like a fish tank water heater. The heater turns on when the water gets under a certain temperature, so the total wattage is less than the full rating of the heater unit because it operates at a duty cycle in most cases. A PTC will also operate in a similar fashion except it will stay on all the time but instead lower it's own power output as the temperature rises.
The max power will never be exceeded unless the unit can put out more power at first until the temperature rises. We dont know this information yet either. IF that's true, then the unit may put out more power than expected using the linear rule. This is doubtful though so the estimates of around 60 watts are probably accurate enough.
 
PTC means "positive temperature coefficient", which means the resistance of the element increases as the temperature increases. This means that the above calculations will yield a lower than actual power value at your decreased voltage and hence power & temperature. The amount of error depends on the coefficient magnitude and the temperature of the element.
A lower resistance at a lower temperature will give more power, not lower power, at the lower voltage then as calculated from a constant resistance.
 
If you want the temp to be stable as in not change rapidly with time, add some mass to your heat source, maybe put the heat source in a breez block.
 
A lower resistance at a lower temperature will give more power, not lower power, at the lower voltage then as calculated from a constant resistance.
I know. That's what I thought I said. I stated that the calculation will give a lower power than actual (therefore actual is higher than the calculated value); in the second part of the sentence I stated that the power and temperature are less when powered from a lower voltage [than when powered from a higher voltage]. At half voltage, the power is lower than at the rated full voltage, which means lower temperature and lower resistance [than full voltage]; this means the power at the lower voltage will be higher than calculated [with assumed constant resistance]. I concede that my sentence wasn't explicit or necessarily unambiguous.
 
I know. That's what I thought I said. I stated that the calculation will give a lower power than actual (therefore actual is higher than the calculated value); in the second part of the sentence I stated that the power and temperature are less when powered from a lower voltage [than when powered from a higher voltage]. At half voltage, the power is lower than at the rated full voltage, which means lower temperature and lower resistance [than full voltage]; this means the power at the lower voltage will be higher than calculated [with assumed constant resistance]. I concede that my sentence wasn't explicit or necessarily unambiguous.
Yes, I didn't read your post correctly. My error. :oops:
 
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