RE: [CAD_CAM_EDM_DRO] Re: pulse generator

Here is a source of inexpensive kits.

If you want to make the process of wiring

A bit simplified.



http://www.ramseyelectronics.com/cgi-bin/commerce.exe?preadd=action&key=UT5A



Regards,

Don B



_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of caudlet
Sent: Wednesday, March 24, 2010 11:28 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: pulse generator







--- In CAD_CAM_EDM_ <mailto:CAD_CAM_EDM_DRO%40yahoogroups.com>
DRO@yahoogroups.com, "toolmkr" <dkmach2@...> wrote:

>
> Hello,
> I am setting up a stepper motor to drive a mechanism at variable
> speeds, 0-60 rpm Spec sheets for the motor and driver can be found on

Anaheim Automation web site, the motor model is 34Y214S-LW8 and the driver
model is MBC10641. The tech support person at Anaheim Automation advised me
that I would need to purchase an external "pulse generator" in order to make
the setup work as I would like. I need to be able to change the speed of the
stepper motor on-the-fly without having it connected to a computer by simply
turning a knob such as on a potentiometer.

> He told me I would be able to pick up a pulse generator from Radio Shack,

however I was at the store and they were not too helpful.

> Any assistance would be appreciated.
>
> Sincerely,
> Denis

Depending on wheather you need direction as well as variable speed the 555
circut will work. At those speeds (really low RPM) there will be a degree of
vibration even with microstepping. We have a conveyor oven for surface mount
PCB's with a stepper turning a gear reduction and using a 555 circuit. It
vibrates.

You you want a wider range of frequencies with a 50% duty cycle then the
CD4046 (74HCT4046) is a VCO (voltage controlled oscillator) that uses a
single cap and resistor (pot) to sweep across a wide range. It also allows
you to put in an acceleration curve by putting a cap in the voltage input
pin. Getting 0 RPM (no pulses) is harder with either circuit because at
really low pulse rates the circuit get unstable.

Any direction needs to come from a switch unless you want to add a lot more
circuitry.

>

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