Speed - Parallel vs serial ( was Re: Motor

--- In CAD_CAM_EDM_DRO@y..., "JJ" <jj5412@e...> wrote:

> the volt meter. Now while holding the A- and A+ wires on the

battery,

> connect B+ to the + end of the battery. If you don't see a twitch,
> you've gotten lucky and that's a pair of coils. If you do see a

twitch,

Hi J.J.

Should the above read?

> the volt meter. Now while holding the A- and A+ wires on the

battery,

> connect B+ to the + end of the battery AND B- TO THE - END OF THE

BATTERY. If you don't see a twitch,

> you've gotten lucky and that's a pair of coils. If you do see a

twitch,

Rest of original message follows

> Okay, I did a lot of driving today, so I had time to think about

this.

> This may or may not work.
>
> Use a DVM to find the coil wires by checking resistance between

wires.

> Label them something like A, B, C and D.
>
> Now, switch the meter over to DC volts. Connect coil A to the meter.
> Give the motor a spin, and note the polarity of the voltage. If it's
> positive, label the motor wire connected to the red meter lead +, if
> negative, label the wire connected to the black lead +. Label the

other

> wire - if you want. Repeat for B, C and D, turning the motor the

same

> direction each time.
>
> Go get a flashlight battery. If your motor is less than 1.5 volts,

use a

> 10ohm resistor in series with it. Put a little mark on the motor

shaft

> so you can see it move. Connect A-, B-, C- and D- to the - end of

the

> battery. While watching the motor shaft, connect A+ to the plus

end. You

> should see a twitch in one direction or another. If you don't see a
> twitch check A- and A+ with the ohm meter, then check the battery

with

> the volt meter. Now while holding the A- and A+ wires on the

battery,

> connect B+ to the + end of the battery. If you don't see a twitch,
> you've gotten lucky and that's a pair of coils. If you do see a

twitch,

> take B+ off and try C+, then D+, all the while keeping A+ connected.
>
> Now, if you see a twitch with all the coils, try connecting B+, C+

and

> D+ to the - end of the battery, and connecting B-, C- and D- to the

+

> end of the battery, one at a time. If you still see a twitch, then I
> don't have a clue :-)
>
> I don't have any 8 lead motors lying around, but I believe this will
> work for you.
>
> BTW, I have unipolar motors and used the battery twitch method to

find

> out the coil sequence. By connecting both center taps to the - end

of a

> D cell, I touched the other wires to the + end until I found the

right

> sequence so all the twitches were in the same direction.
>
> Hope that helps.
>
> Regards,
> JJ
>
> Be Kind, Be Careful, Be Yourself