How Do Aqaurium Heater Elements Control Amps?

[MitchJi]

Hi,

I am curious.

How do the heating elements control the wattage?

All the controllers for our True Temp Heaters are the same. It is the heating elements that will range in size. We offer them in the following wattages:
150w
300w
500w
800w
1000w

This is the kit:
JBJ True Temp Titanium Heating System Kit for Aquariums
The Controller

The heating element:

Thank You!

 

[bobc]

The heater is a resistor. max power is V^2/R. That will be the quoted wattage. different elements have different resistances.
The controller just allows the mains on to it from time to time (most likely using a zero crossing detector to make the switching electrically quiet)


probably.......

 

[dogman dan]

Yep, length and thickness of the nichrome wire inside. Then it's just turned on and off with an adjustable thermostat.

Much like the oil filled electric radiators I use to heat a room. They have switches for various wattages. They just turn on elements one at a time, or both of them.

 

[MitchJi]

Thanks!