[TCML] How To Turn A Vacuum Cleaner Motor Into A Synchronous Motor

[Teslalabor]

I also think it doesn't work even if the motor runs @ 3000rpm. You have to 
check it with a scope, attach a disk with neodymium magnets to the modified 
motor, wind a small coil and check the phase on the scope.

Stefan

----- Original Message ----- 
From: "dave pierson" <dave_p at comcast.net>
To: "Tesla Coil Mailing List" <tesla at pupman.com>
Sent: Monday, December 06, 2010 8:30 PM
Subject: Re: [TCML] How To Turn A Vacuum Cleaner Motor Into A Synchronous 
Motor


>> A vacuum cleaner motor can be made to run at synchronous speed with
>> the addition of a diode; actually 2 in parallel for mechanical balance
>    There is a deal of difference between running at 3,000 rpm
>    and running synchronously.
>
>> Mains vacuum cleaner motors are usually series wound AC brush motors.
>> The one I removed from a 1100 watt Miele cleaner ran at 18,000 rpm and
>> drew 5 amps at 240 volts.
>
>> Having dismantled it, I soldered two 3 amp 1000 volt diodes across  2
>> opposite commutator segments (180 deg apart),  tucked down behind the
>> commutator.
>    A circuit drawing would help.  Slowing a motor form 18,000 to
>    3,000 is by half wave rectifying is a deal different than
>    synchronous operation.
>
>> One would have done but to maintain physical balance, I used a pair
>>  opposite each other and applied a liberal amount of epoxy resin to
>> stop  them flapping about.
>
>> The motor is still series connected as before and runs at 3000 rpm (at
>> 50 Hz) quite happily from 30 volts AC where it draws 0.8 amp to 80 volts
>> AC where it draws 5 amps at no load.
>
>> One  thing that I haven't looked at yet is the phase change of the
>> rotor as the load varies but it is probably no worse than an
>> induction motor with flats machined on it.
>   An induction motor is quasi synchronous in any case, with
>   a better lock with the flats.  A series commutator motor
>   is inherently controlled by voltage/current.
>
> best
> dwp
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