Re: Gecho 210 step multiplier, was Re: [CAD_CAM_EDM_DRO] Stepper Math

I'm impressed! That's one heck (or should I say, Geck) of a lot of stuff
going on in that little package. So is this how the mid-band stabilization
is performed?

Thanks for the detailed description.

Paul R. Hvidston, N6MGN
ACKSYS Engineering
Upland, CA

----- Original Message -----
From: "mariss92705" <mariss92705@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, February 25, 2002 3:14 PM
Subject: Gecho 210 step multiplier, was Re: [CAD_CAM_EDM_DRO] Stepper Math


> Hi,
>
> The pulse multiplier (G901) is a phase-locked loop circuit. Its
> output goes to a G201 10 microstep drive. Its purpose is to appear
> like a full-step or half-step drive to the user while it moves the
> motor with microstep smoothness.
>
> In full-step mode, all motor movements are in 10 microstep
> increments. If you send it 200 step pulses, it will output 10 times
> 200 or 2,000 pulses to the 10 microstep drive it sits in. The motor
> will take 1 revolution, just like a full-step drive, except the motor
> will turn without vibration or resonance.
>
> Here's how it works in full-step mode:
>
> The steps you send it increment a 4-bit up/down counter. The
> counter's outputs go to a 4-bit D to A converter. The D to A output
> goes thru a PID compensation amplifier. Its output goes to a VCO
> (voltage controlled oscillator). The oscillator output goes to the
> G201 step input and to a divide by 10 counter. The counter's output
> decrements the 4-bit up/down counter, which closes the loop.
>
> In operation, the VCO frequency divided by 10 exactly tracks the
> input step pulse rate. This means the VCO frequency is exactly 10
> times higher than the input step frequency. It tracks the input
> whether it is accelerating, decellerating or running at a constant
> speed. The microstep smoothness is set by the PID loop co-efficients.
> These values are based on optimum loop transient (lag-lead) response.
>
> Mariss