RE: Re: Jog Dial - where can I buy ?

["Ward, David" <David.Ward@xxxxxxx>]

Tim,

Detent, is generally a term used to indicate that there is a mechanical
'notch' or 'bump' at each encoder position to give user tacktile feedback
o=
f
each increment

The outpus are quadrature. That is to say that the encoder will output two
pulse trains which together indicate both direction and speed.  Speed is
simply the rate of pulses (In the example below 64 per rev.)  Direction is
determined by the phase relationhip between the two pulse trains e.g. If A
leads B then CW and vice-versa

You can extract direction with a simple flip-flop (Better explanation than
mine here http://www.doug-smith.net/kf6dx7.pdf)

This link has a couple of nice pictures of a wiping contact encoder
http://coel.ecgf.uakron.edu/grover/web/ee263/labs/Quadrature%20Encoder.pdf


As an example RS lists this bourns encoder :

263-2873	Encoder,optical,rotary,22x16mm,	64 cycles per revolution
=A334.42

To me that'd be expensve for a home project, but it's a personal thing

Dave

-----Original Message-----
From: Hawes,Timothy Edward (GEG) [mailto:haweste@xxxxxxx]
Sent: Thursday, May 22, 2003 8:39 AM
To: ukha_d@xxxxxxx
Subject: RE: [ukha_d] Re: Jog Dial - where can I buy ?


Dave,

I was just browsing and found the same part  :-)  Looking at the datasheet
I'm now unsure as to whether I'll get it to work with my limited
electronic=
s
knowledge. I was hoping to add each direction "contact" and the
push-button
directly to a VIOM module. Is this still possible as the datasheet starts
talking about debounce circuits ?

I'm also unclear on is what's meant by the terms "detent" and
"quadrature" =
?

I was after an "endless" rotary action. Now I know what I'm
looking for
(i.e. encoders, thanks Patrick) CPC do sell plain encoders (part of Farnell
I guess).


Thanks,

Tim H.
(P.S. how expensive is "expensive" ?)

> -----Original Message-----
> From: Ward, David=20
>=20
> A search of bourns turned up http://www.bourns.com/2/pdfs/EPS.pdf=20
> a quadrature rotary encoder with a push switch option
>=20
> HTH=20
>=20
> Dave
>=20
> -----Original Message-----
> From: Patrick Lidstone
>=20
> --- In ukha_d@xxxxxxx, "Hawes,Timothy Edward (GEG)"=20
> <haweste@a...> wrote:
> > Hi all,
> >=20
> > I'm looking to buy a jog dial for a home-brew project I'm
working=20
> on - ideally around 1" diameter, momentary push button and pref.
back=20
> lit. CPC don't seem to sell them and googling only turned up
products=20
> *with* jog dials.
> >=20
>=20
> Jog dials rule! I've not been able to find one with the push-select=20
> action. The rotary bit is easy enough - look for rotary encoders or=20
> digital rotary encoders. Farnell do a simple rotary encoder which=20
> outputs a dual pulse train which is phased depending on direction
on=20
> speed of rotation for about three quid. I made do with a separate=20
> push button for the select action immediately below the jog dial.
>=20
> Patrick
>=20

+


** UKHA2004 BE THERE! ** - start planning now.

http://www.automatedhome.co.uk=20
Post message: ukha_d@xxxxxxx=20
Subscribe:  ukha_d-subscribe@xxxxxxx=20
Unsubscribe:  ukha_d-unsubscribe@xxxxxxx=20
List owner:  ukha_d-owner@xxxxxxx=20

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/=20