Electrical Engineering

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Tony Kao

12:34 AM

@PlasmaHH With 60000 matches you can do a pretty accurate approximation of pi youtube.com/watch?v=sJVivjuMfWA

6 hours later…

jippie

6:05 AM

@PlasmaHH it's a synchronous motor. Where did you find it? They are commonly used in clocks because ... they're synchronous. Disadvantage is that they have low torque at startup.

There are two ways to make the motor run in a given direction, some sort of locking mechanism that mechanically forces the motor to not turn in the wrong way, or an extra winding (usually of different length and different diameter copper) to actually make a magnetic field that revolves in one direction. I think this motor is of the latter type.

W5VO

6:41 AM

@jippie I would have guessed a shaded pole motor since it's probably single phase

jippie

@W5VO Not familiar with the term shaded pole. Let me google that before I hit the shower.

@W5VO I think you are right.

The difference would be in the rotor (magnetized or squirrel cage), but I think it is indeed a shaded pole async then.

/me is out.

abhi

i am computer science student i am very much interested to build my own small robots whc is the good place to start

PlasmaHH

7:25 AM

@jippie it is the fan motor of a 1980s microwave.

@TonyKao cool, you come and help me count, wont you?

@abhi a robotics course at your university

@jippie I cant think of a reason they need to be synchronous there...

I will disassemble this thing when I get home so we can see what the rotor is... I can remember seeing such similar things in clocks indeed... bud what are the thicker copper wires for? they seem to just be holding the other parts together?

2 hours later…

abhi

9:10 AM

no robotic is't available , i am good with languages and web technology which i learn by my self i hope it willl be same for all

@PlasmaHH can u guide me on how to start

abhi

9:22 AM

@JavaRocky

@JavaRocky can you guide ?

3 hours later…

Scott Seidman

12:42 PM

raforanz

1:39 PM

Hi Guys.. its been a long time since I visit here lasttime

Hi @jippie

2 hours later…

PlasmaHH

3:10 PM

I am wondernig if maybe electronics.stackexchange.com/questions/166286/… is a very elaborate spam seed

PlasmaHH

3:56 PM

can you extend an oscilloscope probe cable by just adding some bnc and recompensate?

3 hours later…

jippie

7:18 PM

@PlasmaHH It is a shorted winding. A current is induced into it which results in a summed magnetic field that revolves. With two poles, the rotor wouldn't rotate very well as the field would just swap.

Shaded-pole motor

Shaded-pole motors are the original type of AC single-phase induction motor. A shaded-pole motor is basically a small squirrel-cage motor in which the auxiliary winding is composed of a copper ring or bar surrounding a portion of each pole. This auxiliary single-turn winding is called a shading coil. Currents induced in this coil by the magnetic field create a second electrical phase by delaying the phase of magnetic flux change for that pole (a shaded pole) enough to provide a 2-phase rotating magnetic field. The direction of rotation is from the unshaded side to the shaded (ring) side of the...

It is in line with @W5VO's suspicion.

PlasmaHH

7:46 PM

@jippie yep, that totally makes sense

W5VO

8:26 PM

@PlasmaHH Unlikely, but I removed the bitly links

@PlasmaHH The coax will push you out of compensation range fairly quickly, I suspect. Maybe 1-2 ft?

PlasmaHH

@W5VO 50cm and just barely being able to compensate it

W5VO

heh... good guess