current limiter for 230v

[ravni]

Hi. I have a 2300watt water heater element. Is there a relatively easy methode to control the amount of power I'm putting into it? So that I can use it as a etc. 1000watt element..

 

[KerimF]

The simplest one is a dimmer using diac & triac. But it is not a recommended solution since it generates high interference on the power line. So using it depends on your location and if there are or not sensitive sets connected also to the power line.

 

[crutschow]

You could also a large Variac but they tend to be big and somewhat expensive.

 

[jiripolivka]

If you have two 1-kW heaters, you can connect both series and get 500 W heat output. With one alone, you get 1 kW. With both in parallel, you get 2 kW. So with a simple switch you can get three levels, simply and without electronics and interference.

 

[KerimF]

A more complex solution is by using a continuous on-off timer with a period of a few minutes for example.
The idea is to turn on (and off) the heater's current for an interger number of mains cycles (at voltage zero crossings).

 

[crutschow]

To implement KerimF's suggestion, you can use a solid-state, zero-crossing relay to control the heater.

A few minutes ON may be too long, depending upon the thermal time-constant. You may want the ON/OFF period to be in seconds or even fractions of a second. You could use a 555 configured as a variable (PWM) astable multivibrator to control the ON/OFF duty-cycle.