Re: D/A converter info

ok thanks for the reply. I see you are in north tx. I am in Euless.
tach circuit right on. I have a 60 tooth sprocket and 2500rpm so that
would be 2500pps. I have an iotech data acquisition system I would
like to be able to get rpm to but it only has voltage or current
inputs. then set up a pid for the drive. trying to po boy a plc,
since its already installed.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "caudlet" <thom@t...> wrote:
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "gary_vincent_2001"
> <gary_vincent_2001@y...> wrote:
> >
> >
> > Hi guys, I am looking for a D/A converter to take mag pickup
pulses
> > and get back a proportional dc voltage. Anything like that out
> there?
> > tks gary
>
> What you are describing is basically a tachometer circuit. How
> linear and how accurate and how many pulse per second will
determine
> how/what you spend. A true D/A takes a digital "word" and gives
you
> a voltage level that corresponds but is not designed to take serial
> pulses in and give you a voltage level. The process of doing that
is
> to use an 'integrator' circuit (simple op amp) but the trick starts
> to become things like linearity and response time. One chip we use
a
> lot to take PWM in and output a porportional DC voltage is the
LM2907
> chip.
>
> Tell us what you are trying to measure and we can give you a
> suggested approach. If you are trying to measure position or speed
> there are different solutions. If you are trying to control the
> speed RPM of a cutter motor there are known solutions the group
have
> developed as well as some vendors.