PLL/PWM solution? Re: [sdiy] CV to rotary encoder?

[Cynthia Webster]

Hi!

What about actually rotating an encoder via the same Pulse Width Modulation
type of circuit that drives Futaba type radio controlled airplane servos?

Midi can even bus used with these to make midi controlled robotics

some ideas here perhaps...

http://www.midivid.com/robopro.html


Cynthia


on 4/29/03 11:08 AM, Grant Richter at grichter at asapnet.net wrote:

> OK, I am not absolutely certain about how current this information is, this
> is off the top of my head. I had to build an encoder simulator to test
> theatrical rigging controllers which used incremental encoders.
> 
> There are two types of encoders, absolute and incremental. An absolute
> encoder outputs direct binary relating to it's position.
> 
> An incremental encoder uses two square wave signals with a 90 degree phase
> separation (quadrature). The direction of travel is indicated by which phase
> leads the other. I seem to recall one is a reference phase and the other can
> reverse direction just by inverting the signal.
> 
> This requires a 4 state machine which can be built from a 555, 4024 and
> 4052. You just tie input pins to high or low to form the correct signals.
> For reference X out phase 1 (X0, X1 +)(X2, X3 gnd) Yout phase 2 (Y1, Y2
> +)(Y0, Y3 gnd) invert phase 2 to switch direction.
> 
> Hope this helps.
> 
>> From: Paul Perry <pfperry at melbpc.org.au>
>> Date: Tue, 29 Apr 2003 14:26:16 +1000
>> To: synth-diy at dropmix.xs4all.nl
>> Subject: [sdiy] CV to rotary encoder?
>> 
>> A lot of gear now has a rotary encoder..
>> there is probably an easy way to make a CV to rotary encoder
>> converter, so when the CV increases by yea much, the encoder
>> goes foward one unit and so on.
>> Or just keeps going up while CV is above a threshold, back
>> when below it.
>> 
>> paul perry melbourne australia
>> 
>> 
>