Stoves without thermostats

[Chetlaham]

"You say that you would like to try the control in #13. It is not an oven control."

Of course!



Its offensive for you to think that I don't know its for surface unit.

"There is nothing special about it. Most GE and Hotpoint ranges had the 5 heat switches for the surface units and, while they did not look the same, early Westinghouse & Frigidaire ranges had them, too, but you jumped the track from talking about ovens without thermostats to surface unit switches that allow a certain fixed wattage input without the need for thermostats."

Its not a jump track- I want to apply the same concept to an oven- which is what I have been imagining all along. Have 3 or 4 heating elements inside the oven and using various series/parallel/on/off combinations to achieve multiple temperature options. If it works for a surface burner, why not an oven.

 

[lowefficiency]

>> If it works for a surface burner, why not an oven.

You absolutely could make what you're describing for an oven, and you absolutely could cook food in that oven.
But using it would be a miserable process.

Surface burners have controls which vary their heat output, but only as a percentage of their maximum output, not as a temperature setting. They can do this because the thermostat in the system is YOU, the cook!

Surface burner controls are like the accelerator pedal on your car. Let off the pedal and you get your idling engine's minimum output. Floor it and you get your engine's maximum output. But no position of pressing the pedal strictly correlates with vehicle speed - it is up to the driver to vary the pedal input to accelerate to, and maintain, their target speed. Want to go 40 mph on flat ground? It might take a medium amount of pedal. Want to go 40mph up a steep mountain incline? It might take most of the pedal's throw and significant laboring of the engine to do so. Want to go 40mph DOWN a steep incline? You may need to let off the pedal entirely.

The human driver adjusts the power input to what is necessary, just as you do for a pan cooking pancakes, or a huge pot boiling water. On a vehicle, the cruise control is a good equivalent for the thermostat - set the cruise control to 40mph, and it throttles the engine as necessary to maintain your speed regardless of the conditions.

For an oven, you could do the equivalent manual process, having multiple taps of fixed power level inputs. But to obtain your target temperature will take a lot of waiting, monitoring, and adjusting. It becomes very easy to overshoot and burn your pie, or undershoot and change the way your meal cooks. Recipe guidance is based on a measurable time+temperature quantity - take away the stability of the temperature, and the cook time also varies, meaning you have more guesswork and checking to see if things are actually done. And you toss repeatability out the window - a pizza baked tomorrow will take a different amount of time than your pizza did today, just because of the temperature swings, heat soak, etc. Recipe books would be a disaster, as there would be no consistency between oven brands or models, let alone adjustments for the local climate or other factors that influence the temperature inside the oven. And the system becomes extremely sensitive to interference, such as heat loss when opening the oven door.

Doesn't sound very fun, does it?

 

[Chetlaham]

I fully agree with everything you said. Preheating would take a long time too, which would be a downfall.

Though for me its fun enough to try.

 

[lowefficiency]

Theoretically, you could preheat in an identical amount of time. With or without a thermostat, the preheating would just be turning everything on full power and waiting until the desired temperature is reached, then turning it down to a reasonable power level to maintain that temp.

But you would have to be paying attention, as a failure to change the setting would be equivalent to starting a self-clean operation!

 

[mrboilwash]

Not sure if such a stove would meet today`s safety standards, maybe if a thermal fuse was part of the system and I wonder what the benefits might be as thermostats aren`t that expensive anymore.
On the other hand I don`t think a Schalterbackofen ever reached temperatures even close to self cleaning even if someone forgot to turn it down.
Suppose overall maximum Wattage was way too low. The suggested 10 min preheating time rather seems like a bit of a prewarming. Guess you just had too put the food in early because of economical reasons, in other words to save on current.
Just think of early electric clothes irons, they were more in the 300 W range if at all vs. about 1000 W when thermostats became the norm.

 

[kimball455]

When I got my house it had a Magic Chef stove. There was no thermostat on the over, you varied the flame just as like surface burner. I got quite good with temp control. Use that stove for years until the oven interior fell apart from rust and age.

 

[combo52]

Reply #15

If the oven was designed to be able to only reach about 450 F it would be near useless, you would never be able to do even simple things like baking cookies where you need nearly 400F and you are oping and closing the door at least every 5 minutes as you rotate two sheets of cookies.

 

And when you do a large roast or turkey it might even be dangerous because the food might not cook quickly enough to stay safe.

 

OK I'll bite, what is the point of building an oven without automatic heat control, it seems a little building a car without brakes or steering, it might be beautifully simple but about useless.

 

John L.

 

[Chetlaham]

@mrboilwash, that is the plan. The total oven wattage on high would be such that the oven could not overheat.

Combo52: You have a point, opening the door would cause a very big drop in temperature which would take a much longer time to recover from. Also large foods as Turkeys will probably pull the temp down substantially. Though as you know I am curious to see the severity in reality.

An oven without a thermostat would have the pros of being more reliable, no swinging temperatures once stabilized (Breville has built its business on this and yes I am aware they use an electronic thermostat) and possibly being cheaper. PRC (Peoples Republic of China) is already building warmers and compact ovens with fixed PTC resistors- a somewhat similar concept.

And to the person who liked reply #17- life is short to be filled with so much malcontent. Let people imagine, let others try something new even if it might fail in the end.

 

[mrboilwash]

Did a little research on Ebay and there are still some of these stoves to be found. Looks like they made it well into the 1950`s just because they were cheaper to buy than a "Reglerbackofen" (one with an infinite thermostat).

An AEG model has a picture of a somewhat corroded rating plate where the top element is rated 600 and the bottom element is 500 Watts if I`m not mistaken.
Those German pre and postwar stoves were not turkey size of course, but a roasted duck or goose could be made in a reasonable time.
The most powerful one I could find has 1500 Watts for both elements together, which is almost as much as one of the "weaker" thermostat controlled ones of that time.

It may also be worth to mention that an electric stove that can only be controlled over 11 possible combinations of top and bottom heats instead of a thermostat is still a godsend over a wood or coal fired stove.

https://www.ebay.de/itm/Antiker-AEG-Elektroherd-freistehend-3-Platten-Backofen/264385048168?hash=item3d8e93ae68:g:aJwAAOSwW3VaxkQs

 

[Chetlaham]

Mr. Boilwash, thank you! This is immensely inspirational. The more I think about it the more I smittened by it.

And yes, I am not surprised at all. The elements will have to be of lower power to prevent the oven from going over say 500-600*F.

 

[kenwashesmonday]

fan-of-fans<span style="display: inline !important; float: none; background-color: transparent; color: rgb(255, 0, 0); font-family: Arial; font-size: 13.33px; font-style: normal; font-variant: normal; font-weight: 700; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"> [COLOR=#000000; font-family: Times New Roman; font-size: medium]wrote:[/COLOR]</span>

<span style="display: inline !important; float: none; background-color: transparent; color: rgb(255, 0, 0); font-family: Arial; font-size: 13.33px; font-style: normal; font-variant: normal; font-weight: 700; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"><span style="text-align: left; color: rgb(0, 0, 0); text-transform: none; line-height: 20px; text-indent: 0px; letter-spacing: normal; font-family: Times New Roman; font-size: 16px; font-style: normal; font-variant: normal; text-decoration: none; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; float: none; -webkit-text-stroke-width: 0px; background-color: transparent;">"<span style="display: inline !important; float: none; background-color: transparent; color: rgb(0, 0, 0); font-family: Times New Roman; font-size: 16px; font-style: normal; font-variant: normal; font-weight: 700; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">This model has the three heat switches for the upper and lower elements, but I guess it is a thermostat on the side of the oven" </span></span></span>

 

 

<span style="display: inline !important; float: none; background-color: transparent; color: #ff0000; font-family: Arial; font-size: 13.33px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"><span style="text-align: left; color: #000000; text-transform: none; line-height: 20px; text-indent: 0px; letter-spacing: normal; font-family: Times New Roman; font-size: 16px; font-style: normal; font-variant: normal; text-decoration: none; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; float: none; -webkit-text-stroke-width: 0px; background-color: transparent;"><span style="display: inline !important; float: none; background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">I'm thinking that may be a simple thermometer.  The cook would watch the thermometer and manipulates the switches accordingly.</span></span></span>

 

<span style="display: inline !important; float: none; background-color: transparent; color: #ff0000; font-family: Arial; font-size: 13.33px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;"><span style="text-align: left; color: #000000; text-transform: none; line-height: 20px; text-indent: 0px; letter-spacing: normal; font-family: Times New Roman; font-size: 16px; font-style: normal; font-variant: normal; text-decoration: none; word-spacing: 0px; display: inline !important; white-space: normal; orphans: 2; float: none; -webkit-text-stroke-width: 0px; background-color: transparent;"><span style="display: inline !important; float: none; background-color: transparent; color: #000000; font-family: Times New Roman; font-size: 16px; font-style: normal; font-variant: normal; font-weight: bold; letter-spacing: normal; line-height: 20px; orphans: 2; text-align: left; text-decoration: none; text-indent: 0px; text-transform: none; -webkit-text-stroke-width: 0px; white-space: normal; word-spacing: 0px;">I believe that Hotpoint came out with the Calrod heating element in the late 1920s.  Is it possible that these ranges are older than that?</span></span></span>

 

 

 

[Chetlaham]

I want a wiring diagram to one of those ovens, either the Hotpoint or the German version.

And yes, I also suspect that may be a state... hoping that it is LOL.

 

[mrboilwash]

Have a look at the 4th picture

Bitte entschuldigen Sie die Störung...

 

[Chetlaham]

Oh man, I owe you big time!

Now that, is how you wire a stove. Very ingenious.

Do you know what the elements say left to right btw?

 

[mrboilwash]

The ones on the left are the top oven elements (Bratrohr oben), on the right are the bottom ones.

 

[Chetlaham]

Very elegant way of doing it.

So I would imagine one set of top and bottom elements for medium, both sets for high and in series for low?

 

[combo52]

Building an oven without a thermostat

Is just plain stupid, If it was designed so it could never go over 500-600F it would be nearly useless for baking or broiling.

 

It would not get hot enough to broil well.

 

It would take too long to preheat for baking.

 

It would end up using more energy because it would take so long to preheat and then eventually overheat.

 

It would bake very poorly because it could not recover when food was added and would result in too much temperature fluctuation, a decent souffle would be impossible.

 

It would be dangerous as many foods would eventually catch fire, and wasteful as much more food would be ruined.

 

 

Yes at one time both gas and electric ovens were built without thermostats because thermostats were expensive or not available at a reasonable cost, these ovens were more powerful and could easily reach temperatures over 700 F quickly.

Many of these early ovens were destroyed by forgetful users, or the fire department when they responded to a fire, LOL

 

John L.

 

[tomturbomatic]

Underwriters Laboratories would never allow such a thing to be built and sold with their approval and without the UL sticker, they cannot meet requirements for sale because sellers have to be responsible for selling safe appliances just as manufacturers have to be responsible for not building and marketing dangerous appliances. Fire insurance companies would not insure a building with one in it. The concept is a fever dream of one who knows little of reality.

Knapp Monarch, Toastmaster and other brands made their cheapest models of table toasters without thermostats, but they were minimally powered units used with supervision. If you are interested in studying about these devices, the magazines are available.

 

[Chetlaham]

Food catching fire

Not if you turn down the heat. Set to preheat- then turn it down a few notches. Even if left on preheat mode the elements would not be strong enough to push it past 550*F.

Preheating will take time though I can not deny this, and yes food will lower the temp taking time to recover.

But if played right I can see it working reasonably well.

Perhaps it might be time for me to look into PTC technology.

 

[Chetlaham]

UL listing

What UL listing requires ovens to have a thermostat or a high limit?

"One who knows little of reality."

You have no way of knowing what I know and don't know, so saying this is just both dumb and silly.