Re: Pulse Multiplier

Mariss,

That sounds like a lot of work! PLL's (Phase Locked Loop) are used in
RF work quite a lot, I wonder if a VCO, PLL and programmable divider
could work in this application? Perhaps the PLL would not have enough
range?

Just a thought

Alan

Mariss Freimanis wrote:

>
> Ernst,
>
> I am not using pulse doubling. The way the pulse multiplier works is
> as follows:
>
> 1) The STEP pulses you send clock a 4-bit DOWN counter.
>
> 2) A wide dynamic range (20Hz to 200kHz), non-linear (logrithmic V in
> vs. F out) VCO sends its pulses to variable modulus counter (divide
> by 1, 2, 4, 5, and 10).
>
> 3) The output of the modulus counter clocks a 4-bit UP counter.
>
> 4) The outputs of the UP and DOWN counters go to the inputs of a 4-
> bit ADDER.
>
> 5) The 4-bit output from the ADDER (SUM) goes to a non-linear D to A
> converter.
>
> 6) The output of the D to A goes to a PID compensated ERROR
> amplifier, whose output then goes to the VCO, closing the loop.
>
> 7) The SUM is also compared against a reference value. If it equals
> or exceeds this value, the VCO is synchronously shut-off until the
> next STEP input. This prevents the VCO from ever generating more
> pulses than the called-for multiple of the STEP input.
>
> 8) The VCO output is buffered and sent on to the motor drive.
>
> Unlike a one-shot, the resultant VCO pulses are evenly distributed
> with time. That is to say, if the modulus is 10, there are 10 evenly
> spaced VCO pulses over the STEP pulse period. They maintain this
> distribution regardless of the STEP pulse frequency. Below a STEP
> frequency of 2Hz the VCO pulses come in bursts of 10, .5 sec per
> burst.
>
> All this requires 8 ICs, 24 resistors, 9 capacitors, 3 transistors, 2
> diodes, a dual opto-isolator and 9 dual header pins for option
> jumpers. It all fits on a 1.25" by 1.375" by .125" (32mm by 35mm by
> 3mm) module that fits snugly inside either the G201 or G320 drive.
> All surface mount components of course.
>
> Mariss
>
> --- In CAD_CAM_EDM_DRO@egroups.com, Ernst Aardal <eaardal@o...> wrote:
> > I just wonder, when you use frequency (pulse) doubling you must use
> a one shot monostable.
> > How long is each puls in the 1x and 10x mode.
> > Is this a box that you can supply for other stepper-amplifiers?
> > Ernst
>
>
>
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