4 ms·

Mechanical Induction Cooker (2015)

25 points by 112233 4y ago

QuadmasterXLII 4y ago
"Many Moving Magnets Melting Metal" https://www.youtube.com/watch?v=l8PxXZoHTVU https://www.youtube.com/watch?v=l8PxXZoHTVU If you want to see this concept tried in real life, Codyslab has a video. From the description: "I stick a bunch of magnets to the flywheel of a diesel engine to show off some cool science."
- noneeeed 4y ago
  What a great channel! I need to show this to my kids, they love this sort of thing.
aaron695 4y ago
Answered first line - > A hot plate [sic] (includes induction) typically draws 1000 to 1400 watts. > A Tour de France cyclist typically generates 300 to 350 watts. Joe Average on a bicycle will go over 150 watts only in short bursts. Halfbakery does better math than HN, can't seem to pin down the conclusion either though. Which is it's a dumb idea, or rework the numbers and show where a non-dumb idea might lead.
deleted 4y ago
[deleted]
jeffalyanak 4y ago
This might be feasible in a setting with multiple people providing power, but I'm not sure how usable it would be with just one person. As a rough rule of thumb, an average person riding a a bike at about 15 km/h would be using 30-40 watts of power. Let's assume that this cooking device would be twice as hard to pedal. If it converted your pedaling with 100% efficiency—which it certainly wouldn't—it would give you a peak output of 80 watts of power. In that case, you'd still only get about 80 Watt-hours of energy after 1 hour of pedaling. For context, it takes about 90 watt-hours of energy to boil 1 litre of water, so you'd be pedaling over an hour to boil it. In fact, that's ignoring the rate at which the water is dissipating heat out into the air. You might not even get it to boil at all. For this to work at all, you'd need many sets of pedals to allow multiple people to put energy in. With 10 people pedaling in the above scenario you'd be getting 800 watts, which would be usable for a lot of different types of cooking.
- amelius 4y ago
  One of the comments addresses this too: > A hot plate typically draws 1000 to 1400 watts. > A Tour de France cyclist typically generates 300 to 350 watts. Joe Average on a bicycle will go over 150 watts only in short bursts. > (And remember: muscles generate heat, too - and they're only 18-25% efficient. So the power peddler will be heating up, but won't have the cyclist's breeze cooling their body down... ) > -- lurch, Jun 07 2015
  - jeffalyanak 4y ago
    Something to keep in mind is that a hotplate or inductive cooktop may not need to run at full duty cycle depending on the heat dissipation of the materials involved and the setpoint of the themrostat or temperature probe. It may be pulling its maximum rated power while it comes up to temperature, but it'll be regulated by some sort of thermostat. Once it's at temperature the rate of heat dissipation of the hob, pan, and even the ingredients themselves will affect how soon it'll drop below the threshold and power draw will resume. A system with a lower maximum power would still work, but it would be running at a higher duty cycle to maintain the same temperature. It would take longer to get to the set temperature in the first place and slower to bring it back to temperature whenever the temperature drops. That said, I'm pretty confident that 700-800 watts would be useful for many types of cooking and I think it's achievable with a dozen or so people pedaling.
  - toss1 4y ago
    Olympic cyclist working to toast a slice of bread. Insanely impressive effort by a maximally trained professional, and he's definitely toasted. This is like a cartoon technology — the general concept is right, but the scale is just waay off... Anyway, worth the look https://www.youtube.com/watch?v=S4O5voOCqAQ https://www.youtube.com/watch?v=S4O5voOCqAQ https://www.popularmechanics.com/science/energy/a15889/bike-racer-toaster-challenge/ https://www.popularmechanics.com/science/energy/a15889/bike-...
- agumonkey 4y ago
  I want to assemble a gym club with a few rows of bike and suck up the mechanical energy production to power some stuff. People pay clubs and then pay to power machines to then waste energy. Seems cosmically absurd to me.
eig 4y ago
In addition to the problem of measly human power (mentioned in other comments), generators are only efficient when the magnets are quite close to the conductor so the metal pots/heating element would have to be held ~2mm from the rotating magnets. Generators succeed in this because they have a small metal housing that holds everything rigid. I don’t see how this could be practical for a large cooktop. Also the material of the pot/heating element (Al vs Nichrome) only changes the optimal gearing ratio for the bike wheel.
bob1029 4y ago
I would be more interested in an induction cooker that has a traditional mechanism of action, but with a far more user-friendly, analog control scheme. The primary challenge with induction is that you cannot really control the heat transfer with cookware placement. There are some that try to emulate this but it is "laggy" and inconsistent at best. For whatever reason, my brain keeps coming back to something approximating a foot pedal you can use to directly control the amount of current that flows through the element. Remove all of the digital control circuitry and let the user be 100% in the loop. Safety issues be damned. Many are cooking with open flame, so I really don't see the relative concern here. Today, I prefer induction simply because of the speed. I can bring several liters of oil up to 400F in < 4 minutes. Boiling water for tea takes less than 45 seconds. The tradeoff is the heat control. I've got 5kW of power, but its wrapped in these horrible kid gloves right now.
- jeffalyanak 4y ago
  I'd be happy with knobs! The biggest issue I've seen with consumer induction cooktops is that all the affordable ones use stop touch/tap interfaces that make it really difficult to adjust heat while cooking. If the primary input was just a potentiometer (or rotary encoder, if they wanted to be fancy) it would be trivially easy to set or adjust any hob at any time.
  - 2Gkashmiri 4y ago
    https://www.amazon.in/Lifelong-Inferno-LLIC30-Induction-Cooktop/dp/B088K321BQ/ref=sr_1_5?crid=1BH2Q9889SW2W https://www.amazon.in/Lifelong-Inferno-LLIC30-Induction-Cook... this one costs around US$15. me and many millions of consumers in india use devices costing around this $12-$20 priced induction cookers because that's the only thing being available... everyone has a soft button interface which sucks but because of the relatively cheap capital cost, you are able to buy a new one if the old one breaks. with good care i've used a machine not different from above for 4-5 years nonstop
    - jeffalyanak 4y ago
      Yeah, aside from the actual interfaces I think induction units are great. They are safer than most (all?) other types of cooker, they're super fast to reach set temperature, and they have the potential to last a really long time. I just really want at least one inexpensive unit like the one you linked to come out with a knob for temperature control. Surely that wouldn't affect the cost that much?
isoprophlex 4y ago
> Problem: I do not have a good feel for the amount of energy needed to heat a pan vs the amount easily generated by a pedal. If you would need to pedal for hours to get the pan hot that would not be good. Boy do I have some bad news for you
postultimate 4y ago
This one is stupid even by halfbakery standards. So you're going to burn food in a 20% efficient process to heat food ? Rather than just burning the food directly at 90+% efficiency ?
klyrs 4y ago
Worse idea occured due to misunderstanding the title: mechanical friction cooker. Clamp a pot to the "stove" which is a spinning metal wheel. Great for people who distrust magnets and/or don't want to buy a new pot before the bottom wears through.
- alexvoda 4y ago
  That is brilliantly absurd.
fantasticfears 4y ago
I read nothing out of this webpage

25 points by 112233 4y ago

"Many Moving Magnets Melting Metal" https://www.youtube.com/watch?v=l8PxXZoHTVU https://www.youtube.com/watch?v=l8PxXZoHTVU If you want to see this concept tried in real life, Codyslab has a video. From the description: "I stick a bunch of magnets to the flywheel of a diesel engine to show off some cool science."

noneeeed 4y ago
What a great channel! I need to show this to my kids, they love this sort of thing.

aaron695 4y ago

Answered first line - > A hot plate [sic] (includes induction) typically draws 1000 to 1400 watts. > A Tour de France cyclist typically generates 300 to 350 watts. Joe Average on a bicycle will go over 150 watts only in short bursts. Halfbakery does better math than HN, can't seem to pin down the conclusion either though. Which is it's a dumb idea, or rework the numbers and show where a non-dumb idea might lead.

deleted 4y ago

[deleted]

jeffalyanak 4y ago

This might be feasible in a setting with multiple people providing power, but I'm not sure how usable it would be with just one person. As a rough rule of thumb, an average person riding a a bike at about 15 km/h would be using 30-40 watts of power. Let's assume that this cooking device would be twice as hard to pedal. If it converted your pedaling with 100% efficiency—which it certainly wouldn't—it would give you a peak output of 80 watts of power. In that case, you'd still only get about 80 Watt-hours of energy after 1 hour of pedaling. For context, it takes about 90 watt-hours of energy to boil 1 litre of water, so you'd be pedaling over an hour to boil it. In fact, that's ignoring the rate at which the water is dissipating heat out into the air. You might not even get it to boil at all. For this to work at all, you'd need many sets of pedals to allow multiple people to put energy in. With 10 people pedaling in the above scenario you'd be getting 800 watts, which would be usable for a lot of different types of cooking.

amelius 4y ago
One of the comments addresses this too: > A hot plate typically draws 1000 to 1400 watts. > A Tour de France cyclist typically generates 300 to 350 watts. Joe Average on a bicycle will go over 150 watts only in short bursts. > (And remember: muscles generate heat, too - and they're only 18-25% efficient. So the power peddler will be heating up, but won't have the cyclist's breeze cooling their body down... ) > -- lurch, Jun 07 2015
- jeffalyanak 4y ago
  Something to keep in mind is that a hotplate or inductive cooktop may not need to run at full duty cycle depending on the heat dissipation of the materials involved and the setpoint of the themrostat or temperature probe. It may be pulling its maximum rated power while it comes up to temperature, but it'll be regulated by some sort of thermostat. Once it's at temperature the rate of heat dissipation of the hob, pan, and even the ingredients themselves will affect how soon it'll drop below the threshold and power draw will resume. A system with a lower maximum power would still work, but it would be running at a higher duty cycle to maintain the same temperature. It would take longer to get to the set temperature in the first place and slower to bring it back to temperature whenever the temperature drops. That said, I'm pretty confident that 700-800 watts would be useful for many types of cooking and I think it's achievable with a dozen or so people pedaling.
- toss1 4y ago
  Olympic cyclist working to toast a slice of bread. Insanely impressive effort by a maximally trained professional, and he's definitely toasted. This is like a cartoon technology — the general concept is right, but the scale is just waay off... Anyway, worth the look https://www.youtube.com/watch?v=S4O5voOCqAQ https://www.youtube.com/watch?v=S4O5voOCqAQ https://www.popularmechanics.com/science/energy/a15889/bike-racer-toaster-challenge/ https://www.popularmechanics.com/science/energy/a15889/bike-...
agumonkey 4y ago
I want to assemble a gym club with a few rows of bike and suck up the mechanical energy production to power some stuff. People pay clubs and then pay to power machines to then waste energy. Seems cosmically absurd to me.

eig 4y ago

In addition to the problem of measly human power (mentioned in other comments), generators are only efficient when the magnets are quite close to the conductor so the metal pots/heating element would have to be held ~2mm from the rotating magnets. Generators succeed in this because they have a small metal housing that holds everything rigid. I don’t see how this could be practical for a large cooktop. Also the material of the pot/heating element (Al vs Nichrome) only changes the optimal gearing ratio for the bike wheel.

bob1029 4y ago

I would be more interested in an induction cooker that has a traditional mechanism of action, but with a far more user-friendly, analog control scheme. The primary challenge with induction is that you cannot really control the heat transfer with cookware placement. There are some that try to emulate this but it is "laggy" and inconsistent at best. For whatever reason, my brain keeps coming back to something approximating a foot pedal you can use to directly control the amount of current that flows through the element. Remove all of the digital control circuitry and let the user be 100% in the loop. Safety issues be damned. Many are cooking with open flame, so I really don't see the relative concern here. Today, I prefer induction simply because of the speed. I can bring several liters of oil up to 400F in < 4 minutes. Boiling water for tea takes less than 45 seconds. The tradeoff is the heat control. I've got 5kW of power, but its wrapped in these horrible kid gloves right now.

jeffalyanak 4y ago
I'd be happy with knobs! The biggest issue I've seen with consumer induction cooktops is that all the affordable ones use stop touch/tap interfaces that make it really difficult to adjust heat while cooking. If the primary input was just a potentiometer (or rotary encoder, if they wanted to be fancy) it would be trivially easy to set or adjust any hob at any time.
- 2Gkashmiri 4y ago
  https://www.amazon.in/Lifelong-Inferno-LLIC30-Induction-Cooktop/dp/B088K321BQ/ref=sr_1_5?crid=1BH2Q9889SW2W https://www.amazon.in/Lifelong-Inferno-LLIC30-Induction-Cook... this one costs around US$15. me and many millions of consumers in india use devices costing around this $12-$20 priced induction cookers because that's the only thing being available... everyone has a soft button interface which sucks but because of the relatively cheap capital cost, you are able to buy a new one if the old one breaks. with good care i've used a machine not different from above for 4-5 years nonstop
  - jeffalyanak 4y ago
    Yeah, aside from the actual interfaces I think induction units are great. They are safer than most (all?) other types of cooker, they're super fast to reach set temperature, and they have the potential to last a really long time. I just really want at least one inexpensive unit like the one you linked to come out with a knob for temperature control. Surely that wouldn't affect the cost that much?

isoprophlex 4y ago

> Problem: I do not have a good feel for the amount of energy needed to heat a pan vs the amount easily generated by a pedal. If you would need to pedal for hours to get the pan hot that would not be good. Boy do I have some bad news for you

postultimate 4y ago

This one is stupid even by halfbakery standards. So you're going to burn food in a 20% efficient process to heat food ? Rather than just burning the food directly at 90+% efficiency ?

klyrs 4y ago

Worse idea occured due to misunderstanding the title: mechanical friction cooker. Clamp a pot to the "stove" which is a spinning metal wheel. Great for people who distrust magnets and/or don't want to buy a new pot before the bottom wears through.

alexvoda 4y ago
That is brilliantly absurd.

fantasticfears 4y ago

I read nothing out of this webpage