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

["Hawes,Timothy Edward (GEG)" <haweste@xxxxxxx>]

Dave,

See below, many thanks,

Tim H.

> -----Original Message-----
> From: Ward, David
>=20
> Tim,
>=20
> Detent, is generally a term used to indicate that there is a=20
> mechanical
> 'notch' or 'bump' at each encoder position to give user=20
> tacktile feedback of
> each increment

Ahh good, an encoder *with* detent is what I'm after.

> The outpus are quadrature. That is to say that the encoder=20
> will output two
> pulse trains which together indicate both direction and=20
> speed.  Speed is
> simply the rate of pulses (In the example below 64 per rev.)=20=20
> Direction is
> determined by the phase relationhip between the two pulse=20
> trains e.g. If A
> leads B then CW and vice-versa
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> You can extract direction with a simple flip-flop (Better=20
> explanation than
> mine here http://www.doug-smith.net/kf6dx7.pdf)
>=20
> This link has a couple of nice pictures of a wiping contact encoder
> http://coel.ecgf.uakron.edu/grover/web/ee263/labs/Quadrature%2
0Encoder.pdf

Excellent - looks like I've got some interesting lunchtime reading :-)
=20
> As an example RS lists this bourns encoder :
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> 263-2873	Encoder,optical,rotary,22x16mm,	64 cycles per revolution
> =A334.42
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> To me that'd be expensve for a home project, but it's a personal thing

I agree - I was looking for something a bit cheaper ;-) The part Stuart
fou=
nd in CPC looks just the job.

>=20
> Dave
>=20
> -----Original Message-----
> From: Hawes,Timothy Edward (GEG)=20
>=20
> Dave,
>=20
> I was just browsing and found the same part  :-)  Looking at=20
> the datasheet
> I'm now unsure as to whether I'll get it to work with my=20
> limited electronics
> knowledge. I was hoping to add each direction "contact"
and=20
> the push-button
> directly to a VIOM module. Is this still possible as the=20
> datasheet starts
> talking about debounce circuits ?
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> I'm also unclear on is what's meant by the terms "detent"
and=20
> "quadrature" ?
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> I was after an "endless" rotary action. Now I know what
I'm=20
> looking for
> (i.e. encoders, thanks Patrick) CPC do sell plain encoders=20
> (part of Farnell
> I guess).
>=20
>=20
> Thanks,
>=20
> Tim H.
> (P.S. how expensive is "expensive" ?)
>=20
> > -----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=20
> pref. back=20
> > lit. CPC don't seem to sell them and googling only turned=20
> 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=20
> 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

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