Why do microwave turntables switch directions each time they’re turned on?
They don’t. You’re just forgetting which way it turned the last time.
Actually, this is microwave specific, yours just does it because for whatever reason the designers made it that way. I’ve actually never seen one that does this. Most I’ve seen only turn one way, or do not have a turntable at all. This latter type seems to be getting more popular. (Less moving parts to fix, I guess)
My GE Spacemaker XL switches rotation direction, too.
Just a WAG that some engineer figured out that this would somehow extend the service life of some part or parts involved in the rotation.
The hampsters are much more motivated if they don’t have to run on the wheel the same direction all the time. Thus microwaves with bi-rotational turntables, automobiles with forward and reverse gears, and the space shuttle which goes way out there and then returns.
c’mon guys…
Is that the best you can do? I thought this was the famous straight dope message board. I gotta confess, I’m a little disapointed.
It’s the AC man! It’s allways the AC.
The AC will get you… eventualy
Welcome to the board Samui. Looking for why a microwave turntable changes direction is not a great subject of interest for many dopers. Now, asking why grapes sparkle in the microwave? That is more like it! :
http://www.geocities.com/Tokyo/Temple/3717/Geeks/eegrape.htm
Seriously, I think the switch of direction is done to ensure that the food will be evenly cooked:
From a new Sharp microwave manual:
“The turntable in the oven reverses direction. Is this normal?
Yes. The turntable reverses direction at random intervals.”
Come on guys! This is a serious question, and as such requires a serious answer.
It’s becouse the cheapest single phase electromotor that can be had is the synchronous two-pole motor. The initial direction of rotation depends on the position of the rotor within the electric field, which for all practical purposes is rando,. Thus the perceived randomeness of the rotation.
For a brief description of how an electric motor works, look at HowStuffWorks
But I guess that’s what puk meant as well.
actually, I found the same link you did, but wasn’t sure this guy was serious or not.
Guess I didn’t want to get baited