Stepper interface
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Another newbie here...
I need to interface a BS2 to a linear actuator (Thomson Airpax L92421-
P1). This actuator is driven by a 5 volt stepper. I plan to send
output from the BS2 pins to logic-level FETs to drive the stepper
coils. Reverse biased diodes would be placed across each of the motor
leads to handle spikes.
Can I safely use a single 5 volt power supply for both the stepper
and VDD on the BS2, or would this risk damaging the stamp? Would some
kind of filter be needed on the input to VDD?
My apologies if this has been covered before. Any links would be
appreciated.
I need to interface a BS2 to a linear actuator (Thomson Airpax L92421-
P1). This actuator is driven by a 5 volt stepper. I plan to send
output from the BS2 pins to logic-level FETs to drive the stepper
coils. Reverse biased diodes would be placed across each of the motor
leads to handle spikes.
Can I safely use a single 5 volt power supply for both the stepper
and VDD on the BS2, or would this risk damaging the stamp? Would some
kind of filter be needed on the input to VDD?
My apologies if this has been covered before. Any links would be
appreciated.
Comments
>Another newbie here...
>
>I need to interface a BS2 to a linear actuator (Thomson Airpax L92421-
>P1). This actuator is driven by a 5 volt stepper. I plan to send
>output from the BS2 pins to logic-level FETs to drive the stepper
>coils. Reverse biased diodes would be placed across each of the motor
>leads to handle spikes.
>
>Can I safely use a single 5 volt power supply for both the stepper
>and VDD on the BS2, or would this risk damaging the stamp? Would some
>kind of filter be needed on the input to VDD?
You probably won't hurt the stamp, but consider the following:
In actual practice I won't connect a logic power supply to "motors"
or inductive loads. Most FETS (not every one) have built in
suppression diodes so check this before adding more.
If you insist on doing this be sure to de-couple your power supply near
the stamp with a .1 uF capacitor and a 100uF or larger electrolytic
capacitor. I think a Nema 23 size 5 volt stepper phase will be about 1
amp. I would make sure you use at least a 5 volt 3 amp power supply
to be safe.
The one advantage of using 5 volts with a 5 volt stepper is there's no need for
power resistors to drop excess voltage and limit the current in the steppers
phases. But a five volt power supply for a five volt stepper will limit the
stepper
speed to about 400 steps per second. You'll need a power supply 4 or 5 times
the stepper voltage to run the stepper at higher speeds. Say 24vdc. Then you'll
have to use voltage dropping resistors (20 ohms 25 watts if 1 amp per phase)
on each center tap of the stepper motor windings.
I highly recommend you use a 24v power supply (BS2 E series only) connected
to Vin pin 24. This will put some isolation (the stamp 5 volt regulator )
between the
stamp and the motor supply voltage. Good Luck!
Greg Hensley
Lawrence Livermore National Laboratory
Defense Sciences Engineering Division
7000 East Avenue Mail Stop L-369
Livermore, CA 94550
Phone: (925) 423-4850
Fax: (925) 422-2118
Email: hensley1@l...
[noparse][[/noparse]Non-text portions of this message have been removed]
appreciated.
Regards,
Dan
--- In basicstamps@y..., Greg Hensley <hensley1@l...> wrote:
> At 09:11 AM 9/11/2001 , you wrote:
> >Another newbie here...
> >
> >I need to interface a BS2 to a linear actuator (Thomson Airpax
L92421-
> >P1). This actuator is driven by a 5 volt stepper. I plan to send
> >output from the BS2 pins to logic-level FETs to drive the stepper
> >coils. Reverse biased diodes would be placed across each of the
motor
> >leads to handle spikes.
> >
> >Can I safely use a single 5 volt power supply for both the stepper
> >and VDD on the BS2, or would this risk damaging the stamp? Would
some
> >kind of filter be needed on the input to VDD?
>
>
>
> You probably won't hurt the stamp, but consider the following:
> In actual practice I won't connect a logic power supply to "motors"
> or inductive loads. Most FETS (not every one) have built in
> suppression diodes so check this before adding more.
>
> If you insist on doing this be sure to de-couple your power supply
near
> the stamp with a .1 uF capacitor and a 100uF or larger electrolytic
> capacitor. I think a Nema 23 size 5 volt stepper phase will be
about 1
> amp. I would make sure you use at least a 5 volt 3 amp power supply
> to be safe.
>
> The one advantage of using 5 volts with a 5 volt stepper is there's
no need for
> power resistors to drop excess voltage and limit the current in the
steppers
> phases. But a five volt power supply for a five volt stepper will
limit the
> stepper
> speed to about 400 steps per second. You'll need a power supply 4
or 5 times
> the stepper voltage to run the stepper at higher speeds. Say 24vdc.
Then you'll
> have to use voltage dropping resistors (20 ohms 25 watts if 1 amp
per phase)
> on each center tap of the stepper motor windings.
>
> I highly recommend you use a 24v power supply (BS2 E series only)
connected
> to Vin pin 24. This will put some isolation (the stamp 5 volt
regulator )
> between the
> stamp and the motor supply voltage. Good Luck!
>
>
>
> Greg Hensley
> Lawrence Livermore National Laboratory
> Defense Sciences Engineering Division
> 7000 East Avenue Mail Stop L-369
> Livermore, CA 94550
> Phone: (925) 423-4850
> Fax: (925) 422-2118
> Email: hensley1@l...
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]