Idea for a heating element controller

[beelah]

I have an electrician friend that I have asked to build me a controller unit based on the plans that are posted here on this site, but in discussions with him he asked me why not just use the temperature control unit on an electric baseboard heater?

He says that they are usually 220 volts and are ready to go, no need to build a controller.

Has anyone tried this idea before? I tried a search here but could not find any thread that talks about this as an option.

My sense is that basicly they are a thermostat, so I am not certian if it would do the same cycling on and off like most other heating elements.

Anybody have any experience with this good or bad? I have a source of old electric baseboard heaters that are cheap, as in free so if this would work I would like to give it a try.

[MuleKicker]

not positive, but i believe it will cycle. I had a similar heater that i was going to canibalize. It cycled. plus,you might want to check the amps its rated for. may not be as high as you think.

[flip]

I use thermostat of 1200 w and no controller, or 2 thermostats of 600 ,join them in parallel at start,and series to half the wattage works fine for me.

[mrhooch]

It's simple. Once you stop applying heat, guess what? There is no energy being applied to convert the liquid ethanol to gaseous ethanol, so within seconds (the amount of time it takes the for the hot spots to transfer their heat to the wash), it stops boiling.

Any heating controller must use some form of cycle control where they either 1) apply only part of each AC cycle to the element, or 2) rectify it to DC and use some form of PWM (Pulse Width Modulation) which turns the power on and off at the base frequency of the circuit, which is somewhere between 20 - 100 khz. Because of the mass of the system, small pulses average out.

Hooch.

[rad14701]

No, a 240V baseboard thermostat will not provide consistent enough energy for powering a boiler... You need a phase angle or burst fire controller, both of which allow only a portion of the current to flow by switching on and off, via solid state circuitry, many times per second which yields very stable power...

[Centar]

Also an "on/off" type of heat controller (thermostat) creates a small spark every time it's switch opens (turns off), this has been known to be an ignition source in the presents of a flammable atmosphere.....ie. alcohol vapor.....things you might not think of...
If you want a safe and simple controller design check out some of my posts...