An interesting rotary digit display - Infos anyone? - Page 1
Forum section: electronics / projects

author: compet17
author_rank: Regular Contributor
timestamp: October 12, 2018, 11:51:20 am
content: I have these rotary mechanical digit displays from an old aircraft instrument (1997 Sperry-Honeywell). My intention is it to build a clock with them. I already figured out how they work, it's not a big secret. But I'd like to know who made them. Are there other manufacturers of those? Are they still available somewhere? And most importantly: What is the correct name for these things? That would make it easier to google.I have two different types: DS11001 with 11 wires to address all digits separately and DS10006 with 6 connections that works bipolar.Manufacturer logo says "MTI CEDAR ENG. DIV."Any information would be welcome....BTW: Video of the instrument teardown can be watched here:

author: LaserSteve
author_rank: Super Contributor
timestamp: October 12, 2018, 12:26:36 pm
content: Try526 Aviation Way, Cedar City, UT 84721Steve

author: LaserSteve
author_rank: Super Contributor
timestamp: October 12, 2018, 12:29:30 pm
content: They are / were a subcontractor to Honeywell in all probability.Steve

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 12, 2018, 02:53:37 pm
content: this is like a dog to find. it seems after exhaustive hours of search, Hypernetics is the only company in the universe that still supply the Electromagnetic Indicators, or at least keep the picture in the internet... most of the time spent i tried to search how the 10 positions stepper/electromagnetic coils is constructed to no avail...http://www.hyperneticsltd.com/indicators.htmlps: i should deserve a cup or two coffee shipped directly from Switzerland to Malaysia. i should get back my life now

author: compet17
author_rank: Regular Contributor
timestamp: October 15, 2018, 01:21:57 pm
content: Thanks everyone....I have found the MTI company in Cedar City but I thought that they do more like entire aircraft fuselage panels.... maybe I should write them.Hypernetics seems interesting. I have to ask them how much such an indicator costs. I'm sure they are pretty expensive...The construction of the magnets is relatively simple. I have two different types with 12 wires or 6. The 12 wire model is the simplest. There is a magnet on the indicator wheel and 11 coils mounted to the support frame. When you energize one coil, the magnet will attract and the corresponding number will be displayed. So you need one common (ground) wire and 11 wires for the 11 possible positions (0-9 and "-" or empty space).The 6-wire model works in the same way but uses a polarity change. For example all even digits are displayed when common is minus and all odd digits are displayed with plus on common wire. So you only need 5 inputs for 10 positions.Since the digit wheel runs freely, I assume the coils do not have an iron core or the magnet would stick to each coil when trying to move.

author: PointyOintment
author_rank: Frequent Contributor
timestamp: October 15, 2018, 08:16:57 pm
content: I would think they do, actually. The device is claimed to retain its display after losing power, but also to have a nearly frictionless bearing. Something needs to hold it in place when the power is off.