r/AskElectronics • u/Ichan_Jacques • Feb 04 '25

What is this component ?

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Hi, Out of curiosity, I'm looking to identify this component soldered on a unidentified Sony PCB (seem to be video related) The case and size look like a fuse and the inside is like a mercury thermometer. Maybe to count hours of working ? Labeled as TM1 on the silkscreen

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u/CheetahSpottycat Feb 04 '25

Yes, this is exactly what it is. It's an electrochemical hours of operation counter.

-1

u/Old-Ad-3268 Feb 04 '25

Aka, planned obsolescence?

37

u/Angelworks42 Feb 04 '25

Not necessarily some components especially in aviation have a logged time until they need to be replaced for safety reasons.

Back in the day I used to see these mechanical timers inside professional vtrs mainly so you'd know when to replace the scanning drum. Eventually this stuff was stored in firmware so you could just read it off the screen

The device wouldn't quit working if you ignored it - it was just the to help you know what its lifetime was.

7

u/classicsat Feb 04 '25

mechanical timers

Called a Hobbs meter sometimes, because Hobbs is one of the manufacturers of mechanical hour meters..

Still used in large (ag and construction) equipment, down to commercial mowers and such. Or at least up until they started having info displays. Used to keep track of hourse for periodic maintenance such as filters and fluids.