Think outside the box. It seems that a lot of people feel unsafe with a heating element that is more than 325 Watts, 40 Ohms at 115 Volts and would like to replace it. They seem to have a problem getting a replacement element that is in this spec. Instead of replacing the element (which is expensive) why not lower the voltage the required amount to use their heating element at the 325 Watts they want?
This is easy to do by using a circuit element called a buck transformer. The idea is to subtract a voltage from the 115 VAC to lower it the amount necessary so the heating element is producing 325 Watts. First calculate the voltage needed. (Use your measured heating element resistance)
For a 40 Ohm ideal element:
Eneeded = square root of Power x Resistance
Eneeded = square root of 325 Watts x 40.7 Ohms
Eneeded = 115V
Find the voltage needed to subtract using a transformer:
Etransformer = Esource – Eneeded
Etransformer = 115V - 115V
Etransformer = 0V, nothing needed!
For a 36 Ohm element:
Eneeded = square root of 325 Watts x 36 Ohms
Eneeded = 108 Volts
Find the voltage needed to subtract using a transformer:
Etransformer = Esource – Eneeded
Etransformer = 115V = 108V
Etransformer = 7V
If you want to use 120 Volts in your calcultations:
For a 36 Ohm element:
Eneeded = square root of 325 Watts x 36 Ohms
Eneeded = 108 Volts
Find the voltage needed to subtract using a transformer:
Etransformer = Esource – Eneeded
Etransformer = 120V = 108V
Etransformer = 12V
Next find the current rating needed for the transformer:
I = E/R
I = 108Eneeded / 36 Ohms
I = 3 Amps
So in this case you need a transformer rated at 12 Volts at 3 Amps.
Radio Shack has one catalog number 273-1511 rated at 12.6 Volts at 3 Amps for $10.49. This transformer also has a 6.3 V output if you need just 6 Volts.
Maybe someone can draw a picture of how to hook it up. The idea is to hook up the 115 volt winding to the 115 Volts and hook the secondary side (6.3 V or 12.6 V) in series with the 115 Volts so that it reduces the voltage. If it increases the voltage reverse the secondary winding wires. This will allow your 36 Ohms element to operate at 325 Watts instead of 365 Watts. This may be easier and cheaper to do that trying to get a new element.
