Interesting that there's no mention of that goal in your original statement.
Based on what? Point your thermometer at the heating surface. What's the temperature when it first turns on? What's the temperature when it cycles off? That delta-t is the measurement of heat evenness. This can be a big number with a radiant heater. Can be almost zero with a well-designed radiator style heater. The whole idea of the radiator is to have some thermal mass and keep heat even.
They wont wear out in a hurry. I would also be wary of removing the existing thermostat from the circuit, as in most cases, it not only regulates the temperature to the point you set, but also has a second function of "over temperature" emergency cutoff, that will kill power if the temperature exceeds a certain limit. (usually can only be reset by pressing a button once this trips).
While you may think this isn't needed, if it is bypassed and the unit were to overheat, it could start a fire or even rupture from the pressure of the overheated internal oil (if an oil filled heater) , spraying very hot oil everywhere.
A light dimmer type setup, if it fails, will typically result in the internal TRIAC short circuiting, which will leave the heater on full power, constantly, resulting in a risk of overheating. AS a light dimmer also has no "thermostat" to measure the heat coming from the unit, you would have to constantly adjust it as the temperature changes, whereas a thermostat will try to maintain a temperature at a certain level, regardless of the existing room temperature. (ie: if the room is a couple of degrees colder than last night, a thermostat will simply leave the power on for longer time if needed until the desired temp is reached, then shutoff. A light dimmer will still only leave the power on at a % of full, and will not give it any extra to compensate for this. This means you will have to keep adjusting it on a "trial and error" basis to set the right temp as room temperatures change with weather.
there is no thermal mass in this heater.....it is mica-thermic
How about warming the whole floor.
Much less of a problem with efficient windows.
The upward current warms that ordinary cool downward draft. Drafts affect overall rooms comfortability. I installed, or rather insulated my front door, and the room is much better.
You probably shoulda been more accurate with your initial "radiator" description. Garbage in >>> garbage out...
e the
d the
well said, now include the thermal coefficient for the filament...
You forgot to multiply twice the resistance. It will be 1/2 the watts total. Each unit will be 1/4.
greg
2nd attempt to post this reply!
use a saturable core reactor, which is a variable inductor controlled by a DC current through a secondary winding. Used to be made by Northlake near Chicago.
The inductor, with 0 DC current has maximum inductance and 'starves' the resistive load down to 5 to 10%, then at maximum DC current the inductor is saturated and almost all the power makes it to the load. The transfer/control is monotonic, but very weird. L vs Idc
The DC control winding is wound in a 'fgirue eight' pattern so that one adds, one subtracts with no net to the other winding, but due to the high number of turns, saturates the core locally. Saturating locally interrupts the magnetic field lines and is like opening up a large air gap in the core, thus the inductance drops to nil.
I prefer radiant heaters, too. You can point them at yourself and sit very comfortably like in front of a fireplace. Used to have hot air blast heating but that made the room's air excessively hot in order to be comfortable when sitting. Then when you get up and move around you swelter. Whereas with radiant heat, the air can stay cool so when you move around, you're still comfortable. But those contact closures!!! very irritating if you went to sleep, they get very loud.
The variable inductor is great for controlling resistive loads especially in the 1kW to 10kW ranges. ...you can actually make your own if you want.
Is this called a "Variac"?
Not really, a variac is just a variable auto-transformer. giving you a 0-100% range of output vs input voltage, and has a defined curent limit based on physical size.
The variable inductor, is more of a magnetic amplifier type of device and relies on the core of the inductor saturating to vary the series imedpance with the load.
Jeff
No, a variac is a tapped inductor with a wiper to make contacts along the inductor's turns to provide a variable output voltage.. The input voltage is applied to fixed points across the variac's fixed core inductance. Then, by varying the tap for the output, the output voltage can be adjusted.
The ones I've seen usually are rated for 100VA to 500VA, sometimes
1kVA, look like a torroid with bare turns exposed on the top edge. They have a mechanically operated wiper [much like a rheostat, or potentiometer] that by rotating taps into the inductor's windings. By turning the knob the wiper goes from slightly above input voltage down to zero volts. But, most of the ones I've seen have their last turns near zero darkened, or worse, burnt, because the higher currents the lower voltage often supplies, and for some reason the concept of maximum current for a wire size just never comes to mind. People seem to think that 500VA should be able to supply at least 100Watts at 5 volts, NOT!I've seen several types of saturable core reactors. From memory, the multi kW controllers from Northlake [again, from memory costs $150- $250] looked like 3 phase transformers. The center core had the main inductor winding on it and the two legs had the cross wound DC control windings on them. Essentially, the two windings were wired to subtract two large signals to get zero volts, but that never happens very well and there are a lot of energetic signals appearing across the DC control windings. The idea is that the DC windings were a huge number of turns, so 100mAdc would saturate the legs, and, voila! no inductance anymore.
The smaller types, varied a bit. some were cheerio sized with a hole drilled through the side. I've made some in the lab using metglas ribbon cores that I simply punched a hole through from outside to inside to make a place to wind the figure eight.
You can make one from a high quality high voltage isolation transformer, low loss type. Do you have any lying around and feel like drilling it?
|2nd attempt to post this reply! | |use a saturable core reactor, which is a variable inductor controlled |by a DC current through a secondary winding. Used to be made by |Northlake near Chicago. | |The inductor, with 0 DC current has maximum inductance and 'starves' |the resistive load down to 5 to 10%, then at maximum DC current the |inductor is saturated and almost all the power makes it to the load. |The transfer/control is monotonic, but very weird. L vs Idc | |The DC control winding is wound in a 'fgirue eight' pattern so that |one adds, one subtracts with no net to the other winding, but due to |the high number of turns, saturates the core locally. Saturating |locally interrupts the magnetic field lines and is like opening up a |large air gap in the core, thus the inductance drops to nil. | |I prefer radiant heaters, too. You can point them at yourself and sit |very comfortably like in front of a fireplace. Used to have hot air |blast heating but that made the room's air excessively hot in order to |be comfortable when sitting. Then when you get up and move around you |swelter. Whereas with radiant heat, the air can stay cool so when you |move around, you're still comfortable. But those contact closures!!! |very irritating if you went to sleep, they get very loud. | |The variable inductor is great for controlling resistive loads |especially in the 1kW to 10kW ranges. ...you can actually make your |own if you want. | |
Interesting solution though to me it looks like an overkill in space, weight and cost. Modern electronics might not be that interesting but are very effective.
petrus bitbyter
No, any response he doesn't agree with. He can be quite courteous, if you don't say something he finds insufferably stupid.
Thanks a lot!
"Robert Macy"
Not a troll, and there is value to what I say.
** ROTFL !!!Satan is telling us how fine the weather is in hades.....
..... Phil
More important is that he takes his medication on time.
So you speak to Satan? That's no surprise.
And in the very first post too.
"I have one of those 1500 watt radiator style portable electric heaters. Love it"
I know what a radiator style portable electric heater is, but now I have no idea what kind of heater he has.
Still, I wouldnt' worry about contact points wearing out or burning out.
I have six Markel, plus four 'oil radiator' types
I like the Markel's until safety went nuts on them and ruined their effectiveness by making them safe.
Be that as it may, I've lost the contacts on two oil types, out of France? and lost contacts on one Markel. yet all still work if bypassed.
so, I would worry about ruining the contacts.
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