Re: Stepperati Mysteriosi

Don,

What you have there is an MEA motor. Silver in color I'll bet.
The motor is 1.3A per phase (1.3 / fasi)

It probably is a standard PM hybrid 1.8 degree stepper. The 5V, 38V
stuff simply means the drive shown is a bi-level type. Most any drive
should do.

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Don <donkiwi@y...>"
<donkiwi@y...> wrote:

> Gentlemen,
> I have 3 stepper motors (non-permanent magnet) which I have had

for

> some time and I could use some help in evaluating them for CNC use.
> The Motor Plate reads:
> "Motori ed Apparecchiature
> Elettriche s.p.a.
> Ivrea - Italia
> M 41200 - 125D
> N = 4 fasi A = 1.3 / fase"
> Weight is 4lb (1.8 kg). Length is 2.5 inches. Body diameter is 3.4
> inches. Does this make it a "34 frame" ? (By the way; it seems that
> NEMA specs are derived from NATO specs. Are these the same here ?)
> The 6 wires, and the hand-copied Driver Circuit Diagram (No Driver
> electronics) that came with the motors point to it being a 4 phase
> monopolar configuration with 1.8 degrees/step. (I assume that the
> simple on/off series transistors on each phase winding allow only
> monopolar configuration).
> I have a scanned image of the Driver Circuit Diagram, and of a few
> accompanying roughly-sketched connection sheets, but do not know

the

> protocol of posting files here, and can't work out how to upload to

a

> clickable URL anywhere. I can email to anyone obliging enough to

help.

> The Voltage supply options are 5V ("holding"), 12V ("step") & 38V
> ("return")! I have no idea what equipment it is from.
> (Hmmm... 12V step; 38V return... military equipment ?) :)
> I also imagine that the lack of a quoted Supply Voltage on the

Motor

> Plate suggests that a chopper circuit to regulate current would be
> employed, especially since there are series "sense" resistors in

the

> common legs to each phase-pair (The Driver Circuit Diagram is
> confusing on this point: There are two 12 Ohm, 25W resistors

mounted

> on a serious heat sink on the motor body and 15 Ohm, 4W (2x 30R, 2W
> in parallel) in the 12V supply, however, the 38V is shown as being
> switched directly through a darlington to each phase-pair common,
> connecting without series resistors.) ???
> I have no Controller information, but the digital signal names on

the

> diagram and rough "connection sheet" may be a clue to the Wise.
> My dumb questions:
> Is the designation on the Motor plate of "M41200" a recogised
> specification ? (Sanyo have a similar system). (..and

the "s.p.a." ?)

> What suitable Driver might be used for these motors (V, I-reg) ?
> Would the Voltage of Driver Circuits be critical if a chopper type

or

> other regulation of current at 1.3 Amps per phase was used ?
> What torque & power rating would be expected from the specs given?
>
> The motors also have a Moire-Fringe type pulse-transmitter on

their

> shaft (180 slots), which I imagine was used in feedback for a

closed

> loop controller.
> What interesting use might this facility be put to ?
> Is typical servo feedback of similar signal type ?
>
> Some Members may be encouraged to see my attempts at a "real-world"
> project, but I must disappoint them by saying that my MAD_CAM

Torque

> Amplifier project to which these motors have no connection is

coming

> along nicely in parallel. :)
> Any attempts to keep me on the straight-and-narrow path would be
> appreciated.
>
> Cheers. Don.