Induction cooktop with proper powe levels vs pulsating high power levels.

animatt

I am wondering if any of the common induction cooktops have actual graduated power levels.

Like on low say a 200w setting.  Actually having a consistent 200w load. Rather than most that seem to be full power, just not on all the time.

May run full power for 5 seconds then off for 20 or something like that. To get average power usage down.
  While actual cooking is probably pretty close either way, running off an inverter would be nice to have consistent power levels vs pulsating.

Hope that made sense.
I am particularly interested in consumer grade stuff. But any info would be useful.
Thanks

Lumisol

Manufacturers offer both pulsed and non pulsed types in all ranges and prices. Ours is non pulsed, but either will work just as well for cooking.
Both will use the same energy amounts to produce the same temperature outputs.
Either will work as well as the other on an inverter.

animatt

Kind of. If you run a 1500w inverter battery system a pulsed induction cooktop would be less benificial. Say you. Have base loads of say 200-300 watts.  Pulsating to may be 1500 watts [or higher] on the cooktop could fault the system when maybe a fixed power level of say 500 even 1000 watts would work just fine. Consistent power levels allow you more consistently max out a smaller system without faulting.  I also prefer more steady state power usage. A single power spike is kind of ok/ tolerable. Having a peak every 20 seconds  or less is less desirable.
Kind of like having a pressure pump short cycle every 30 seconds.  Steady state is much more friendly.

I imagine most are pulsated as I imagine a programmed timer is all that is needed to simulate a certain output. Would imagine slight cheaper.  And the cookware is a buffer anyway that smooths out power levels.

Obviously in the above I am talking about plug in/ above counter units.

Lumisol

An inverter getting a cooling period between short bursts of usage will keep it running cooler overall vs having it run steady at 50% draw.

westbranch

The fan in my 1500w inverter kicks in at about a 1000w draw ... and if it is currly CFL's 500w below that... 

Lumisol

Get rid of your CFL's immediately, I got rid of ours over 2 years ago. LED's are cheaper now than when I upgraded.
https://www.youtube.com/watch?v=bubJX-m_HSs
there are a lot of these videos. I had one shoot out flames in my hallway light, luckily, it didn't catch anything else on fire.

westbranch

good video...!

animatt

I would  disagree with your analysis. 

First I demonstrated on a small system a constant draw at 50% vs 

100% power for 50 percent of the time

Constant draw would be vastly more benificial.
As in the pulsating situation could usher the whole thing useless. 

And your analysis of running cooler is a bunch of nonsense.

We can examine the situation above.

10 amp at 50% duty cycle.
And
5amp at 100 duty cycle.


I^2R  losses would be 50R for the 10 amp load. 50 percent duty cycle
I^2R losses would be 25Rfor the 5 amp load 100 percent duty cycle.

At 50 percent average load pulsating power has DOUBLE I^2R losses.

At 
10 amp 20% duty cycle.  20R.  I^2R LOSSES
Vs
2 amp 100 duty cycle.  4R I^2R LOSSES.

5X THE DIFFERNECE in I2R loses .  

You should be able to see a pattern.
The difference in I2R losses ends up being 1/duty cycle.

10 percent duty cycle 1/.1= 10x I2R losses for pulsating

The heat has to go somewhere.  That is into the inverter to deal with. The inverter running cooler is a bunch of baloney. 

My breakdown to very simplistic as it does not include many things, like where inverter is most efficient etc.  I am open to more detailed analysis if you care to provide it.


And there could be a myriad of other usages.  Only thing I  can see in favor of pulsating power is cheaper implementation.

My understanding constant loads are winners in most situations. Much less stressful on things.



Curious which cooktop you have that has accurate power levels rather than average power levels?


Matthew

Raj174

I have both, a rather pricey Maytag induction range and an 1800 watt portable counter top version and they both are the pulse type. In fact I have never seen nor heard of a graduated power induction type before. But, I agree, I also would rather have a constant current draw.  I use the portable for cooking as an opportunity load but I don't use it while the my LFP battery bank is near the top of absorb because the pulsing causes the voltage to jump up and down too much. Not good for LFP.

Rick 

Lumisol

animatt said:

I would  disagree with your analysis. 

First I demonstrated on a small system a constant draw at 50% vs 

100% power for 50 percent of the time

Constant draw would be vastly more benificial.
As in the pulsating situation could usher the whole thing useless. 

And your analysis of running cooler is a bunch of nonsense.

We can examine the situation above.

10 amp at 50% duty cycle.
And
5amp at 100 duty cycle.


I^2R  losses would be 50R for the 10 amp load. 50 percent duty cycle
I^2R losses would be 25Rfor the 5 amp load 100 percent duty cycle.

At 50 percent average load pulsating power has DOUBLE I^2R losses.

At 
10 amp 20% duty cycle.  20R.  I^2R LOSSES
Vs
2 amp 100 duty cycle.  4R I^2R LOSSES.

5X THE DIFFERNECE in I2R loses .  

You should be able to see a pattern.
The difference in I2R losses ends up being 1/duty cycle.

10 percent duty cycle 1/.1= 10x I2R losses for pulsating

The heat has to go somewhere.  That is into the inverter to deal with. The inverter running cooler is a bunch of baloney. 

My breakdown to very simplistic as it does not include many things, like where inverter is most efficient etc.  I am open to more detailed analysis if you care to provide it.


And there could be a myriad of other usages.  Only thing I  can see in favor of pulsating power is cheaper implementation.

My understanding constant loads are winners in most situations. Much less stressful on things.



Curious which cooktop you have that has accurate power levels rather than average power levels?


Matthew

It wasn't an analysis, silly, it was a hypothesis. I have no data to analyze, just an induction stove that does not pulse. I guess I have a good one then if what you claim is true. I don't know why they would make both types then unless it's a lot cheaper to make pulsing ones. But why anyone would own one is another story, the costs are just about the same at the point of sale from what I have read on the Maytag site.

animatt

Here is a bump to see if there is economical option to non pulsating induction cooktop especifically at lower power levels.

mvas

What if you contacted these vendors ?
Best 2017 Induction Cooktops
http://inductioncooktopreviews.net/
The mfr can verify whether their cook top pulses ON-OFF or has continuously variable power.

animatt

Well I am back after 2 years. Was going to look up this issue again. To my disappointment my own thread is at the top of the search.   So I guess this is a bump to see if there are any portable induction cooktops with proper power levels, not full power at reduced duty cycle.  

Mike_in_PA

We have a Duxtop 9100MC 15 speed countertop induction unit.   The unit is easy to cook with, good temp control, but the fan is annoying.

On setting 3.0 out of 10 (settings are 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 ), power cycles evenly from 0 up to 625 watts every 15 seconds.  So, watts are 7, 7, 100, 150, 200, 260, 320, 380, 440, 500, 580, 640, 200, 7, 7 in ~ 1 sec steps (edited 7/22)) as reported by the killa watt.  3.0 is good for cooking onions, grilled cheese, and similar--turn down to 2.5 about halfway through.  Not trying to provide a cooking lesson, just some comparative info. Today, a grilled cheese took 7 minutes and used 40 watt hours.  Call it 300 watts continuous.  Rarely go over 5.0 and that is briefly to get a sauce going before turning right back.  Yes, a better power meter would be nice, some graphs, yes, yes. 

We also have a Max Burton 6000.   As I recall, the Max just cycles on and off full power.  Both these units were bought to try out induction prior to purchasing a real top.  

EDIT 7/23.  The above is for an 10" fry pan.  With a 12" pan the power use was higher.  The 9100 MC is on "heat" and again set to 3.0.  I am guessing that more magnetic stainless in the induction field accepts more power with the larger pan.  12" pan used 300 watt hours over 40 minutes, and the peak watts was ~ 740 watts.  Interesting.   

Dave Angelini

I was going to try the one at Costco but I heard caused RF weirdness and killed the AM radio band. Anyone have the costco unit?
It was around $100 with a pan.