Treadmill motor setup and AC vs DC motor operation

[sonnytiger]

I tried using the formula you used to calculate the effective resistance of the inductance, using an inductor I found in a microwave. the inductor I found says 2.7 micro henries. but when I calculated it it came out as being like 0.001 ohms equivalent. which is not even useful. am I doing something wrong? The inductor was stuck on to the end of the magnetron btw.

[tesla500]

@sonnytiger If you're talking about the small RF choke found inside the magnetron's case, then 2.7uH and 0.001Ohm sounds correct. Such a small inductor will have a very low resistance.

[sonnytiger]

@tesla500 ok so its not being used to limit current then?

[Arabhacks]

OK, next time connect the field and armature in Parallel and not series.

Get a DPDT switch and start in series like you normally do.

Now, while the motor is still spinning, briefly disconnect power and switch connections.

And watch the excitement build.

[rompowertube]

Damn I was expecting the cat to come by at 7:10 O_o

That would have hurt!!

nice video

[nestorweld]

RDC??? R for resistance and DC for direct current... all i know is, you can measure resistance w/o DC or AC...resistance in DC measuring??? is that NEW?? resistance - Ω ohms and DC - volts....that is different measuring

[blitzkrueg07]

why did i back away from the monitor when you started the fan LOL

[htomerif]

I sort of guess Im correct in assuming that if it were a permanent magnet DC motor, it wouldn't run at all on AC?

[TalksWithDirt]

That was a great motor for a CNC lathe conversion.

[mrgalleria]

I have found when I convert AC to DC, volts increase about 15% on average. Also, AC volts and amps do not align on the waves scale, so useful energy is decreased using AC, unless a corrective capacitor is used.

[entombed67]

Thanks for the info tesla. By the way ,,great vids.

[entombed67]

My freind at work has the EXACT SAME motor in your video. He asked me if it would make a good windmill generator. Do you have any insight on this ? Thank you.

[tesla500]

@entombed67 This motor is not preferable for a wind generator, because it needs to spin too fast, and it needs power to run the field coils to generate a magnetic field before it will generate anything. A permanent magnet motor would be much more suitable for a wind turbine.

[EETechs]

@tesla500 It is not really a "discovery" per se as you state in the description, but is a well know fact that field wound DC motors can run on AC. About every blender, vacuum cleaner and corded power tool uses a series-wound DC motor which is called a universal motor. Permanent magnet DC motors will not work on AC though. Also another reason DC motors are weaker on AC is because of the zero crossing of AC when it switches polarity. Hence, the armature is coasting during that time period.

[taintedlovergirl]

that cat looks alot like my cat. lol

[omellbin]

make ur own boat

[Hunterc1525]

I love the start up sound

[CVRealMan]

i consider myself to be a fairly smart person but... well you make me feel like an idiot! ^_^

[coondogtheman1234]

Shotgun there you are lol j/k. I had a cat just like yours. longhair barn cat.

Very interesting experiments I thought that motor would just buzz and not spin b/c I've tried this but on a smaller scale 20VAC with a DC motor and it just hums.

[K64250]

Interesting

[Metalcastr]

Please do not cut a slot, it could fly off and kill you or fly through your wall and kill someone else.

[tesla500]

@Metalcastr My plan for containment was to have about one foot solid paper catalogs, then another foot of solid wood all the way around, plus a huge scrap potted transformer on the sides that aren't against the concrete wall. I've tested paper, and the compressed air gun's 500km/h bullet weighing about 100g will only penetrate 3".

Alternatively, I have an indoor storage room I could do it in with 8" thick solid concrete walls on all sides.

[67tr876]

Why did you not run the fan on DC ?

[tesla500]

@67tr876 The fan was run on DC, the motor can barely draw 15A at stall on AC, the fan was pulling about 30A.

[67tr876]

@tesla500 O i see sorry, But dam 30 amp ! did you have this on a 60 amp breaker ?

[tesla500]

@67tr876 Nope, just a standard 15A breaker. They do take some time to trip unless the current is really high.

[heavydiesel]

Be carefull with the max rpm of the fan blade, it may be under what that motor is capable of. :-)

[tesla500]

@heavydiesel Yep, I'm pretty sure it's exceeding the RPM rating. This is the strongest looking blade I've got.

[douro20]

Have you ever worked with the United Technologies motors they use on some DC treadmills?

[tesla500]

@douro20 I do have a couple of other permanent magnet DC treadmill motors, not sure what brand they are, I'll have to check.

[cheetawolf]

maybe you should just burn it up with the fan blade!

[umajunkcollector]

two schools of thought on YT:

1 fix and reapir, restoration to service

2 destroy and junk

I have a bunch of stuff, what shall I do with it?

recycle or land fill

or give it to a junk store for someone else to deal with?

[HDXFH]

That is a good motor too, after the previous damage it took

[Jaytheozzi]

got to love the maths. people dont see how much maths does come into these soer of things. with the proper knowledge of algebra its possible to calculate almost anything.

very good vid!

[HDXFH]

@Jaytheozzi Are you very good at maths?

[Jaytheozzi]

@HDXFH pritty much top of my year level at school but thats not saying allot seeing as i go to a public school. ide be able to figure out those calculations but i wouldnt say im too great.

[HDXFH]

@Jaytheozzi I Was @ the very basic Level , during my school years

[HDXFH]

@Jaytheozzi I can work out these types of calculations, but i wouldn't be great on my own' I'd need a person to guide me through it