Hi all,

I'm studying to design a linear measuring tool like a digital calliper.
I've been considering optical encoder from Avago technology but current consumption is up to tens of mA which is not suited to my design using a battery cell.

My expectation for sensor is as follow:
-Average current consumption is 3 mA or less.
-Price: less than $10 USD.
-Resolution: 0.25 mm or less.
-Measuring range: 20 cm or more.

Hope someone give me some suggestions. Thanks.

 

most mfgrs of digital calipers and micrometers use optical encoders, so there must be some out there somewhere.

 

Digital calipers generally use the capacitive or electromagnetic induction (inductosyn) method of reading a scale. The same way the CUI type of encoders do, which are programmable.
Mitutoyo also used to sell a linear scale kit for DRO's etc.
http://www.mitutoyo.ca/images/catalog/flipviewer_en/flipviewerxpress.html?PN=357
Max.