EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: shimonko on December 17, 2015, 04:50:19 am
-
I recently purchased a (supposedly reputable) $600 blender with a motor rated at 2238 W - one of the most powerful on the consumer market.
Upon receiving it, I was surprised how light it was compared to my similarly priced Magimix food processor which is rated at 650 W. It's 3.75 kg compared to the Magimix's 5.5kg (not weighting bowls etc).
Have motors become lighter in the last 10 years since I bought the food processor? AC motor in the processor versus DC with PWM speed control in the blender? I can't see it stated anywhere if the rated powers are peak or rms, but still this is a huge difference.
-
I think you are experiencing the stupidity that has made regulators look at a number of product areas and start to impose regulations. "Very effective" doesn't sell nearly as well as "look how many watts we burn". The result is appliances with less and less efficient crude motors, burning lots of watts, instead of smart, quiet efficient motors. When we bought our last vacuum cleaner my wife was really eager to get the model below the one we finally bought. It was rated at twice the power, so it must have been better, right? She didn't seem to consider why the top models from the same range took half the power of the cheaper ones. She is typical of the average buyer.
-
They usually don't last long if you run them at full power continuously for long.
That said, you can get small light motors rated at that power for RC planes.
Fist sized.
They use electronically controlled multiphase DC brushless motors running at high frequency to pack lots of power in a small package.
-
I gave our flush mounted Blendtec away to a mate who needed it more than us for his teenagers, haven't seen them since and we hardly ever used it anyway, we replaced it with a crap Aldi magic mix thing just for chocolate milk shakes, some smart cookies are conducting tests on these appliances without the bullshit.
https://www.youtube.com/watch?v=RPWxRXJbEyI&feature=youtu.be&t=913 (https://www.youtube.com/watch?v=RPWxRXJbEyI&feature=youtu.be&t=913)
-
At first I thought you said you were blending chocolate shakes and smart cookies lol.
Not that I bought the thing for the power rating, I was also disappointed that the pulse button isn't operational unless the motor is already running (WTF?). The manual says "This is due to the very high RPM the Pulse button is able to achieve, this is to improve stability of the machine and the attached jug and increase the safety of the machine to comply to safety standards." Sort of defeats the purpose of pulsing. So like the Blentec, I'm beginning to think I've been duped as well.
But good to know about the RC motors. I might put one of those power cost meter things on it to see what sort of power it's at least using.
-
No but you could be onto something, a chocolate milkshake only crunchy might be popular, the joke was that we hadn't seen the kids since.... :scared:
We pulled it out of the kitchen bench and I intended to turn it into a power tool for the workshop, perhaps a small polisher or sander but had a couple of issues, the splined hollow spindle rotates the other way and also you cant program them to stay permanently on although they do have a very nice variable speed with presets, anyway a mate turned up and saw it on the bench and had a better use for it than I did.
This one below.
(https://www.eevblog.com/forum/beginners/blender-power-ratings-trsutworthy/?action=dlattach;attach=187804;image)
-
Not that I bought the thing for the power rating, I was also disappointed that the pulse button isn't operational unless the motor is already running (WTF?). The manual says "This is due to the very high RPM the Pulse button is able to achieve, this is to improve stability of the machine ...
Think of it as a soft start motor setup. As well as lowering the peak current, it will lower the peak torque. It would seem that the torque from a zero start to pulse would be enough to break traction with the benchtop. If so, that could be one wild ride.
-
$600 blender
:o
-
$600 blender
:o
Also, a blender that is built in to the worktop??? What a time to be alive!
Re power rating though, this is that same issue as the endlessly long thread on here a while ago about new EU legislation about efficiency of vacuum cleaners. Manufacturers (especially less than reputable ones) have realised that people see the number of watts on the box and use that as a proxy for cleaning/blending/whatever performance. This creates a clear incentive for manufacturers to make their appliances an inefficient as possible. As long as the rated input power is bigger than the next company's and written in big writing on the box they will sell.
None of the '3000W' vacuums on the market now actually work any better than the 30 year old 800W Henry I've got at home.
-
2238W sounds like a peak or highly intermittent power rating.
A continuous 2.2kW motor looks more like this...
https://www.inverterdrive.com/group/AC-Inverter-Drives-400V/ac-Motor-2kw-3HP-6Pole-6-pole-marelli-MAA112M6-B3/ (https://www.inverterdrive.com/group/AC-Inverter-Drives-400V/ac-Motor-2kw-3HP-6Pole-6-pole-marelli-MAA112M6-B3/)
and that one weighs 25kg.
-
It could be a 200W motor with a 2KW jug element shunt.
That would fit. ;D
-
For what it's worth, the only blender I've managed to not kill (making frozen drinks, which is very hard on the motors) is a KitchenAid, with its whopping 500W motor. It's not the most expensive blender I've killed, nor the one with the highest wattage. What it has is a good jar design, and enough smarts in the electronics to soft-start and supposedly do motor control when it encounters excessive resistance. End result? Smooth daiquiris without lumps, and the thing works like new.
I did have to replace the coupler (the rubber toothed gear that connects to the jar) at year 6. I'm OK with $10 every 6 years.
-
$600 blender
:o
Also, a blender that is built in to the worktop??? What a time to be alive!
Re power rating though, this is that same issue as the endlessly long thread on here a while ago about new EU legislation about efficiency of vacuum cleaners. Manufacturers (especially less than reputable ones) have realised that people see the number of watts on the box and use that as a proxy for cleaning/blending/whatever performance. This creates a clear incentive for manufacturers to make their appliances an inefficient as possible. As long as the rated input power is bigger than the next company's and written in big writing on the box they will sell.
None of the '3000W' vacuums on the market now actually work any better than the 30 year old 800W Henry I've got at home.
Yep, vacuum cleaner turbines are 80 % heater, 20 % motor. The air blowing out of a vacuum cleaner isn't 60+ °C hot for no reason :D
For the same reason they do MORE WATTS they also make them loud on purpose. Over the last few years every vacuum cleaner we bought was louder than the one preceding it ... up to the point that I wear ear protection when vacuum cleaning. vacuum cleaning. ear protection. It's just sick...
-
$600 blender
:o
Indeed! I've bought cars for less than that!
-
I recently purchased a (supposedly reputable) $600 blender with a motor rated at 2238 W - one of the most powerful on the consumer market.
IIRC the standard Australian mains outlet is only rated to 10amps? If the power rating was real, your blender would be very close to the maximum current rating of your outlet :D
As others have suggested, it's probably a peak power with the motor stalled or something similar to generate a big number for marketing.
-
I think you are experiencing the stupidity that has made regulators look at a number of product areas and start to impose regulations. "Very effective" doesn't sell nearly as well as "look how many watts we burn". The result is appliances with less and less efficient crude motors, burning lots of watts, instead of smart, quiet efficient motors. When we bought our last vacuum cleaner my wife was really eager to get the model below the one we finally bought. It was rated at twice the power, so it must have been better, right? She didn't seem to consider why the top models from the same range took half the power of the cheaper ones. She is typical of the average buyer.
This! There have already been law suits in the US about the absurd horse power ratings that some manufacturers are claiming. Also Electric Power in does NOT equal Horse Power out! One of the stunts that manufacturers are using is something called "Peak Horse Power". They take the maximum torque that motor can generate (usually at stall) and then multiply that by the maximum speed that it can run (with no load) and multiple those to get insanely exaggerated horse power rating.
-
$600 blender
:o
I would guess that the name begins with the letter 'V'?
For what it's worth, the only blender I've managed to not kill (making frozen drinks, which is very hard on the motors) is a KitchenAid, with its whopping 500W motor. It's not the most expensive blender I've killed, nor the one with the highest wattage. What it has is a good jar design, and enough smarts in the electronics to soft-start and supposedly do motor control when it encounters excessive resistance. End result? Smooth daiquiris without lumps, and the thing works like new.
I did have to replace the coupler (the rubber toothed gear that connects to the jar) at year 6. I'm OK with $10 every 6 years.
We don't have a KitchenAid blender but we do have a food processor. I have made a pound of home made peanut butter in it without it working hard. I tried it with almonds to make almond butter but I had to break the 1 pound batch into smaller batches as I was seriously heating up the unit ;D Almonds take much longer to break down than Spanish peanuts.
-
$600 blender
:o
Also, a blender that is built in to the worktop??? What a time to be alive!
Yeah, and not only that, but if $600 for a blender is ok, $600 for a microscope to facilitate soldering and PCB inspection just got a philosophical boost :)
-
Power rating of blenders, meat grinders and similar equipment usually are rated with a stalled motor. If you dig into specs/manual deeper, probably you could find a nominal power.
-
For reference
Here is a 2.7kw RC motor
60mm diameter and 85mm long
http://www.hobbyking.com/hobbyking/store/__18129__Turnigy_Aerodrive_SK3_6374_192kv_Brushless_Outrunner_Motor.html (http://www.hobbyking.com/hobbyking/store/__18129__Turnigy_Aerodrive_SK3_6374_192kv_Brushless_Outrunner_Motor.html)
(https://www.eevblog.com/forum/beginners/blender-power-ratings-trsutworthy/?action=dlattach;attach=187969;image)
(https://www.eevblog.com/forum/beginners/blender-power-ratings-trsutworthy/?action=dlattach;attach=187971;image)
-
3.6HP? From that? I don't doubt that it can dissipate 2.7kW of heat, but find it hard to believe it can produce 2.7kW at the shaft for any reasonable amount of time, even with intense forced cooling.
-
PMPO = Peak Meal Power Output
RMS = Real Mushy Soup
-
PMPO .....
That gives me the irrits!!
1200W PMPO - and then you look at the input power requirements . . . AAAAARRGGGHHHHH!!!!
-
3.6HP? From that? I don't doubt that it can dissipate 2.7kW of heat, but find it hard to believe it can produce 2.7kW at the shaft for any reasonable amount of time, even with intense forced cooling.
Of course nothing is 100% efficient so you wont get 2.7kW shaft power, but it should be somewhere close. These motors are never continuously rated, and you simply wouldn't have the battery capacity in most models to get more than the occasional burst of full power.
I certainly doubt that it can dissipate 2.7kW of heat for more than a few seconds!
-
3.6HP? From that? I don't doubt that it can dissipate 2.7kW of heat, but find it hard to believe it can produce 2.7kW at the shaft for any reasonable amount of time, even with intense forced cooling.
Of course nothing is 100% efficient so you wont get 2.7kW shaft power, but it should be somewhere close. These motors are never continuously rated, and you simply wouldn't have the battery capacity in most models to get more than the occasional burst of full power.
I certainly doubt that it can dissipate 2.7kW of heat for more than a few seconds!
They are not far off. I run a smaller 700w rated rc motor on my plane and fly around with the motor getting 500w most of the time.
That 2.7kw motor should handle 1.8kW for a few minutes at least.
In the RC world ratings are for 10sec bursts
As far as battery's go. We have plenty of continuous power for a 2.7kw motor.
Check out this
http://www.hobbyking.com/hobbyking/store/__19159__Turnigy_nano_tech_5000mah_10S_65_130C_Lipo_Pack.html (http://www.hobbyking.com/hobbyking/store/__19159__Turnigy_nano_tech_5000mah_10S_65_130C_Lipo_Pack.html)
10cell 5Ah
65c rated discharge 130c max discharge
So. 65*5 =325amps. * 38V = rated 12.3kW
And 24kW max discharge for 10s bursts
-
$600 blender
:o
I would guess that the name begins with the letter 'V'?
No, a competitor to Vitamix - a Froothie 9400. Nearly 700 reviews on productreview.com.au averaging 4.9/5 was my impulse to buy, but do admit I didn't check out to see if the market was flooded with affiliates.
Speed controller has failed after about 30 uses too, so I've got to return it under warranty.
Wish I could find that power meter so I could see what it's normally drawing.