Analogue datapot

Hi,

haven't come across this before, but I have a unit with several datapots.
They aren't the usual square wave out things, they have 4 connections, and the outputs output a varying analogue output from the (eg 5v) input.

for clarity, 2 pins are 5v and ground. The 2 outputs output 0 - 5v sinewaves when turned, 90 degrees apart I think, so direction can be determined.

Don't even know what these are called, and haven't found anything similar so far.

They are the size of a typical 6mm shaft clicky datapot from Alps or Bourns, but obviously don't click, or have any discrete steps at all.


Unit in question is:
https://www.long-mcquade.com/134528/



Cheers,


Gareth.

 

[Fox's Mercantile]

On 10/22/19 11:17 AM, sound.service@btconnect.com wrote:

for clarity, 2 pins are 5v and ground. The 2 outputs output
0 - 5v sinewaves when turned, 90 degrees apart I think, so
direction can be determined.

Don't even know what these are called, and haven't found
anything similar so far.

Shaft encoders.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

 

On Tuesday, 22 October 2019 18:54:32 UTC+1, Fox's Mercantile wrote:

On 10/22/19 11:17 AM, sound.service@btconnect.com wrote:
for clarity, 2 pins are 5v and ground. The 2 outputs output
0 - 5v sinewaves when turned, 90 degrees apart I think, so
direction can be determined.

Don't even know what these are called, and haven't found
anything similar so far.

Shaft encoders.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

Datapot, AKA Rotary Encoder, AKA Shaft Encoder, usually have a digital output.

This one is analogue.


Cheers,


Gareth.

 

On Tuesday, 22 October 2019 18:54:32 UTC+1, Fox's Mercantile wrote:

On 10/22/19 11:17 AM, sound.service@btconnect.com wrote:
for clarity, 2 pins are 5v and ground. The 2 outputs output
0 - 5v sinewaves when turned, 90 degrees apart I think, so
direction can be determined.

Don't even know what these are called, and haven't found
anything similar so far.

Shaft encoders.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

If you rotate the shaft at a constant rate, I think you get 2 triangle or sine waves out, 90 degrees apart.
(Haven't studied it very closely)

Cheers,

Gareth.

 

On Tue, 22 Oct 2019 11:29:03 -0700 (PDT), sound.service@btconnect.com
wrote:

On Tuesday, 22 October 2019 18:54:32 UTC+1, Fox's Mercantile wrote:
On 10/22/19 11:17 AM, sound.service@btconnect.com wrote:
for clarity, 2 pins are 5v and ground. The 2 outputs output
0 - 5v sinewaves when turned, 90 degrees apart I think, so
direction can be determined.

Don't even know what these are called, and haven't found
anything similar so far.

Shaft encoders.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com


If you rotate the shaft at a constant rate, I think you get 2 triangle or sine waves out, 90 degrees apart.
(Haven't studied it very closely)

Cheers,

Gareth.

Since the device is being powered up and outputs a sine wave doesn't
that mean it must be powered with AC? If that's the case it sounds
like it may be a resolver.
Eric

 

[Mikko OH2HVJ]

sound.service@btconnect.com writes:

Hi,

haven't come across this before, but I have a unit with several datapots.
They aren't the usual square wave out things, they have 4 connections, and the outputs output a varying analogue output from the (eg 5v) input.

for clarity, 2 pins are 5v and ground. The 2 outputs output 0 - 5v sinewaves when turned, 90 degrees apart I think, so direction can be determined.

Don't even know what these are called, and haven't found anything similar so far.

Could it be sin/cos potentiometer ? They usually have contiuous 360°
resistive element and two wipers at 90° angles for sin/cos signals.

They are/were used as absolute encoders and 360° dial settings.

In modern equipment encoders are used more often, but with these you get
non-volatility, analog signalchain and usually quite nice 'know
feeling'.


--
mikko

 

On Wednesday, 23 October 2019 06:08:18 UTC+1, Mikko OH2HVJ wrote:

sound.service@btconnect.com writes:

Hi,

haven't come across this before, but I have a unit with several datapots.
They aren't the usual square wave out things, they have 4 connections, and the outputs output a varying analogue output from the (eg 5v) input.

for clarity, 2 pins are 5v and ground. The 2 outputs output 0 - 5v sinewaves when turned, 90 degrees apart I think, so direction can be determined.

Don't even know what these are called, and haven't found anything similar so far.

Could it be sin/cos potentiometer ? They usually have contiuous 360°
resistive element and two wipers at 90° angles for sin/cos signals.

They are/were used as absolute encoders and 360° dial settings.

In modern equipment encoders are used more often, but with these you get
non-volatility, analog signalchain and usually quite nice 'know
feeling'.


--
mikko

Thanks, Mikko, yes I believe these are indeed a sin/cos potentiometer.

It does have a nice feel in use, but it appears these wear out in exactly the same way the usual digital encoders do, and now I can't find anything remotely similar to replace them with.



Cheers,

Gareth.