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Topic: encoder + 24v dc motor + mega = posable proect (Read 768 times) previous topic - next topic

ez8mm

i came across some cool stuff this week i have a bosh 200mm ball screw in a box slide drveing the ball screw was a 60v dc motor at 3.50 amps on the back was a brake and an optical encoder model Q1/b it has the pin outs on a sticker but i cant find a data  sheet for it ....
the motor seems to be way to high of a voltage for my likeing   :smiley-eek:"what am i gonna do with 60 volts !")  im thinking about finding a simple set of nema stepper motors and driveing it that way. but in the mean time i would like to try and get the encoder to work with the dc motor i can get it to run on 24v stalls out around 12volts so a simple experiment  with the encoder to get to know it would be try to run a constant speed with the encoder reeding to the arduino mega...now i think i could mange getting a rpm reading out of it with some of the examples in the play ground.. but how could i control such a hight amp and volt motor with out spending a fortune on a driver is there semiconductor or a h bridge that could handle it with a pwm signal ?
EZ8MMPRO

ez8mm

well i just got done trying the pin outs for the encoder at 3.3v first then 5v using analog read to check each pin for a Fluctuating value no response had readings from 377 to 1009 and 754 steady  and using digital read i got no further got some that stated high and others that stayed low ? hmm must be doing some thing wrong

ill try to duplicate the sticker pin outs

pin 1 +V        pin3 = A     pin5 = B    pin7 =Z             and 1 blak and white wire it calse drain shiled gos to case as it says
pin 2 com      pin4 = A     pin6 = B    pin8 =Z
does this make sense ?
EZ8MMPRO

MarkT

It does sound rather a high voltage, but remember the higher the voltage the lower the current and thus the thinner the
wires need to be back to the controller (which allows for longer and more flexible cable runs - remember in an industrial
production line you might have hundreds of motors and kilometres of wire!

Motor controllers for that voltage will tend to be industrial units (robotics tends to stick to 12/24V) which will be more
expensive (again they are designed to be reliable for decades in a factory environment and bomb-proof costs money).

Perhaps this is a case where the open-source motor controller project is appropriate: http://www.robotpower.com/products/osmc_info.html  (Only good to 50V that version, but join the yahoo group if you want more info http://tech.groups.yahoo.com/group/osmc/

The encoder might run at a higher voltage of course (common for industrial units).  What current is it taking at 5V on the V+ pin?
[ I won't respond to messages, use the forum please ]

MarkT

A bit of research suggests that the AA, BB, ZZ signals are likely differential pairs (they should be labelled A+ A- B+ B- Z+ Z-) and
they may be 5V logic (RS422 basically) or possibly 24V logic - just to complicate things!  The A and B are quadrature signals (perhaps 1000 cycles per revolution?) and Z is the zero signal (once per revolution) I think.

Using a scope or logic analyzer and 5V would be a good start to see what its doing.
[ I won't respond to messages, use the forum please ]

ez8mm

sweet  i did use the 5 v of the arduino board .. i have 3 matching encoders 2 i would like to use on motrors when ever i get there and the third sthe wires were cut back to the pins  so im useing that one as a test dummy at the moment ..  sadly i cant aford a scope im just a simple at home spare time maker with no funding mostly work of what people give to me as there junk ..  but thats what i tryed to acomplish with the arduino . useing to get an idea of what was doing what ...  it did cross my mind that AA BB ZZ would be -and+ any idea how to use it those leads as -+ would it be - is reverse or is it i have to apply a ground to those - A B AND Z ?  I did open it up to expose every thing and got in there and used a jewrls magnfier to lool around  there was a lot of lines on the disk with a simple legend stateing this  A---   B--  C-  for the lines in the disk i belive it means that the long traces for the wave form are A and mid being B and im guessing Z=C for the short ones .. and what about the shield drin to the case what is that for noise ? that wire is segrageted it the line up of pin outs i left it disconected not know wheather to ground it to the arduino or not .
EZ8MMPRO

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