Tamura Lumitime clock mechanism - Page 1
Forum section: electronics / repair

author: james_s
author_rank: Super Contributor
timestamp: August 25, 2018, 04:05:03 pm
content: I recently picked up a Lumitime clock, this is an early digital clock from the 1970s which uses a motorized mechanism of gears and contacts to switch power to NE-2 lamps forming 7-segment digits. There were numerous different models, most of which used the same internal mechanism. Mine was in need of some significant TLC so I took apart the motor and first set of reduction gears to clean out all the dried up old grease and get things moving again. Unfortunately there turned out to be two tiny washers, one felt and one plastic that ended up on the table and now I'm not sure where these go. Has anyone worked on one of these and perhaps made some notes on where the washers go?The other issue is that the pawl behind the rotor that prevents the synchronous motor from starting in reverse had essentially crumbled into dust. It would be great if I could find a picture of what that is supposed to look like, it may be possible to fabricate something to replace it.These clocks are quite collectible, good working ones often fetch >$100 and the motor is a known trouble point however there seems to be surprisingly little detailed information out there.

author: amyk
author_rank: Super Contributor
timestamp: August 25, 2018, 05:48:41 pm
content: Post pictures please...This is the only relevant service information I could find but it's unfortunately $$$:https://www.samswebsite.com/en/photofact/search/index/samsid/1660_3

author: james_s
author_rank: Super Contributor
timestamp: August 25, 2018, 06:15:16 pm
content: Unfortunately I didn't take many pictures when I had it apart, had I had the sense to do that, I'd have avoided this situation in the first place.I'd be ok paying for a manual if I knew it was for the right thing and had the information I need, however the "Lumitime" name was used on a lot of products including later LED digital clocks and clock radios. I suppose I could keep an eye out for another similar clock and more carefully disassemble that one, hopefully getting both going.I replaced all the neon bulbs in it as I had to desolder them all to get the frame off the PCB to replace a bad resistor and reinstalling the old bulbs with very short leads was almost impossible. About a dozen of them were in bad shape and heavily darkened, mostly those that are on the most. Curiously though the two that are lit continuously to illuminate the starburst were in great shape, I don't know why they held up so well. These are run with 39k resistors on 120V which strikes me as driving them pretty hard, makes me wonder if they should be NE-2H lamps but I had a whole bag of regular NE-2 so I used those for now.

author: Rob190
author_rank: Newbie
timestamp: January 05, 2021, 09:18:09 pm
content: There's a tiny felt washer behind the rotor. I actually lost mine when I cleaned up the motor but it seems to run fine without it.I don't know about the pawl. There's a strange translucent orange ring that goes behind the rotor (and around the washer I mentioned above). It's pivoted on the edge and has small slot opposite. I'm guessing that's the pawl you're talking about but it has never prevented my clock starting in reverse. I can't think why else it would be there though.Rob.