5 ms·

Eh not really, it's just a resistive heating element + impeller + temperature sensor + microcontroller. And implementing PID and tuning the parameters is not th

by gh02t 10y ago

Eh not really, it's just a resistive heating element + impeller + temperature sensor + microcontroller. And implementing PID and tuning the parameters is not that hard as it's such a common and well-known algorithm. I built a sous vide cooker myself with a 500W heating element and tuned it well enough to hold +/- .05 degree in a matter of a couple afternoons for like $20 in parts. The difference with a commercial product is first and foremost safety. You've got high current electricity and moving parts in a high temperature environment, all underwater. The difference between what I made and something like the Anova is that the Anova isn't going to kill someone and also it will work reliably without the user needing to fix and tweak stuff (and that by itself is a feat, considering the environment an immersion cooker is designed to operate in). If I sold what I made as a product it would break and kill someone. All that kind of engineering and also the important work of optimizing user experience is not something manufacturers of most rice cookers care about. It's not worth the extra engineering effort. That said, there are some pretty fancy high-end rice cookers that have pretty precise control and maybe these sort of features may creep in on those, but that sort of rice cooker is a whole different beast than the little Panasonic cooker that lives on my counter.

tptacek 10y ago
At the time when PolyScience released the "Creative series" circulators for something like half the list price of the Pro, apparently the only major difference between the two devices were that the Pro was rated for constant use in food service businesses, and the CS was rated for home use. Both could circulate a bathtub.
- gh02t 10y ago
  Yeah, you have to pay for the extra liability the company incurs by rating things for extreme usage. I draw an analogy with multimeters. I've got a cheapo multimeter with a safety rating that (dubiously) claims it's perfectly fine to jam the leads in an outlet. Would I? Hell no, it'd probably explode. Meanwhile I have a much more trustworth Fluke meter that cost literally 100x more that doesn't really do anything more than the cheapo but I'm not putting my life at risk probing an outlet. You pay for that confidence, not only because there is a much larger engineering effort required to design and test a safe device, but also because you expect that they would be held accountable if their shit gets you killed. A legit safety rating is incurring a substantial liability.
  - StavrosK 10y ago
    Lucky for you, I already jammed my cheapo multimeter into the leads of an outlet, and I'm fine. The multimeter did explode, and it turned out that I was measuring voltage- and had the lead going to the amp section of the meter, so it kept showing 0 after its fuse blew. I figured the socket was dead, good thing I didn't stick my fingers in there.
    - TorKlingberg 10y ago
      I'm not sure you can connect a Fluke's amp meter to an outlet either without blowing it. Hopefully, just a fuse.
      - StavrosK 10y ago
        Yeah, I was being semi-facetious. Clearly it was my fault, and I don't know if the Fluke is that much different in terms of safety from cheapo multimeters. It certainly has other features and works better overall, but I don't see why you wouldn't try to measure high voltages with cheapo multimeters.
        gh02t 10y ago
        There's a huge difference in terms of input protection, actually. Fusing and a bunch of other protection circuits are the first line of protection... most cheap meters will have a glass fuse and little else (some not even that https://www.youtube.com/watch?v=glzLlPO6CjY https://www.youtube.com/watch?v=glzLlPO6CjY), while a better meter will have MOVs, PTCs and many more lines of defense. Nicer meters (especially those rated for working on really high voltages that can cause a literal explosion) will have metal blast shielding around the inputs. There's also isolation- on cheap meters it's pretty common to see poorly laid out circuit boards that have input traces too close together. High voltages will arc right across and boom. The nice meter I have would probably blow a fuse if you connected it to the wall on the current setting, but it's a fast fuse so the rest of the meter would be fine. The fuses in really crappy meters are often quite slow though, so they will blow and cut the circuit but not before the meter gets fried. There are different levels of "crappy" though. A lot of the cheap meters you can get nowadays are safe enough to jam in the wall, I'm not saying "oh you've gotta spend $1000 on a multimeter or you're gonna die." But if you're gonna probe high voltage you'd better get something nice. I have a $5 meter that claims it'd be good at 1000 V, but that is obviously a lie and would be suicide.

by gh02t 10y ago

tptacek 10y ago

At the time when PolyScience released the "Creative series" circulators for something like half the list price of the Pro, apparently the only major difference between the two devices were that the Pro was rated for constant use in food service businesses, and the CS was rated for home use. Both could circulate a bathtub.

gh02t 10y ago
Yeah, you have to pay for the extra liability the company incurs by rating things for extreme usage. I draw an analogy with multimeters. I've got a cheapo multimeter with a safety rating that (dubiously) claims it's perfectly fine to jam the leads in an outlet. Would I? Hell no, it'd probably explode. Meanwhile I have a much more trustworth Fluke meter that cost literally 100x more that doesn't really do anything more than the cheapo but I'm not putting my life at risk probing an outlet. You pay for that confidence, not only because there is a much larger engineering effort required to design and test a safe device, but also because you expect that they would be held accountable if their shit gets you killed. A legit safety rating is incurring a substantial liability.
- StavrosK 10y ago
  Lucky for you, I already jammed my cheapo multimeter into the leads of an outlet, and I'm fine. The multimeter did explode, and it turned out that I was measuring voltage- and had the lead going to the amp section of the meter, so it kept showing 0 after its fuse blew. I figured the socket was dead, good thing I didn't stick my fingers in there.
  - TorKlingberg 10y ago
    I'm not sure you can connect a Fluke's amp meter to an outlet either without blowing it. Hopefully, just a fuse.
    - StavrosK 10y ago
      Yeah, I was being semi-facetious. Clearly it was my fault, and I don't know if the Fluke is that much different in terms of safety from cheapo multimeters. It certainly has other features and works better overall, but I don't see why you wouldn't try to measure high voltages with cheapo multimeters.
      - gh02t 10y ago
        There's a huge difference in terms of input protection, actually. Fusing and a bunch of other protection circuits are the first line of protection... most cheap meters will have a glass fuse and little else (some not even that https://www.youtube.com/watch?v=glzLlPO6CjY https://www.youtube.com/watch?v=glzLlPO6CjY), while a better meter will have MOVs, PTCs and many more lines of defense. Nicer meters (especially those rated for working on really high voltages that can cause a literal explosion) will have metal blast shielding around the inputs. There's also isolation- on cheap meters it's pretty common to see poorly laid out circuit boards that have input traces too close together. High voltages will arc right across and boom. The nice meter I have would probably blow a fuse if you connected it to the wall on the current setting, but it's a fast fuse so the rest of the meter would be fine. The fuses in really crappy meters are often quite slow though, so they will blow and cut the circuit but not before the meter gets fried. There are different levels of "crappy" though. A lot of the cheap meters you can get nowadays are safe enough to jam in the wall, I'm not saying "oh you've gotta spend $1000 on a multimeter or you're gonna die." But if you're gonna probe high voltage you'd better get something nice. I have a $5 meter that claims it'd be good at 1000 V, but that is obviously a lie and would be suicide.