Agh! What's that thing called? Two pins - measured time by cummulative current.

[BitHead]

Like a diode with a barrier junction that 'moves' with current flow - exhibits low impedance while the 'wall' is in the middle and moving but when it gets to the end the impedance goes up.
I'm thinking 'mercury' might be in the name - but not sure - been searching my old text books - scanning indexes and, of course, Googling, but to no avail.
My brain has let it slip - probably last thought of it back in the '80's.
You use it to keep tabs on how long equipment has been on.
What I do recall is that it was often removed in 'the service center' and put into a 'time reader'.
You trickle in 100 nanoAmps in operation and then discharge it with 10 milliAmps - see how long that takes.
So - takes 36 sec. to see that total 'on-time' was 1000 hrs.
What was that little two-pin thing called????
I kind of want one to play with - but need to know what to ask for.

 

[73's de Edd]

Sir ( Four) BitHead . . . . . . ( duly note . . . that I slightly upgraded your worth )

CURTIS was being the magical name, of which I was initially trying to recall.
Now, with the utilization of a past 1970 vintage Allied Radio Catalog, of times long past, I now believe all is explained therein.
I remembered the inert black dye agent mixed within the electrolyte for enhanced visual perception of the gap, but probably never used the info at the right bottom corner, as I was always just referring to the indicator gap for elapsed time.

Now . . . . is this providing . . . . the rest of the story ?

A 10,000 equivalent words of REFERENCING . . . . .



73's de Edd
.....

 

[BitHead]

That is a nifty ol' thing! I vaguely recall looking at that - considering it - deciding it cost too much - doubled total cost of parts on PCB. Maybe this is the thing that made me think 'mercury'. The thing I'm still thinking of (didn't come to me in my sleep - yet) looked pretty much like an axial diode. Now, what would I have called it if I were giving it a name? ... Thanks, 'de Edd, I now have another google-key - 'elapsed time' .

 

[KJ6EAD]

Mercury coulometer.

https://en.m.wikipedia.org/wiki/Mercury_coulometer

https://ntrs.nasa.gov/search.jsp?N=0&Ntk=All&Ntt=mercury column coulometer&Ntx=mode matchallpartial

http://datasheet.octopart.com/120PC12625-Curtis-Industries-datasheet-27869806.pdf

 

[BitHead]

Getting closer! 'Coulombs'! Hmm - I wonder if the thing I'm 'not quite remembering' is a 'not-for-human-reading' version - like maybe it was a little bigger than a DO-214 diode - more like a fuse.
I'm still looking for words like 'increase in impedance'.
That is what indicated that reverse current had 'emptied the bucket' -> stop your stopwatch and convert to 'hours-of-use'.
I recall it was soldered into PCBs in 'stealth mode' - not labeled/documented - so a technically savvy customer would not easily pop the lid and see the thing that, if desoldered, will keep the 'hours of operation warranty limit' from expiring.
Still scratching my head...

 

[(*steve*)]

I remember something many years ago that apparently transferred silver (?) From one electrode to the other. When it was all transferred across there was some significant change in electrical characteristics.

I think I was a young lad at the time, so don't blame me if I have almost everything wrong :-D

 

[BitHead]

!SOLVED! Thanks to *Steve* - google search words -> coulometer silver electronic timer - got me to... coulometric-recorder-for-timing-and-counting-events-in-the-field-kolz-johnson-1976.pdf
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=16&ved=2ahUKEwjb28uBuKbdAhVIhaYKHaSXASgQFjAPegQIABAC&url=http://www.batresearchproject.org/media/1140/coulometric-recorder-for-timing-and-counting-events-in-the-field-kolz-johnson-1976.pdf&usg=AOvVaw17kQtJwW-8xYooQQMCCmZ3
'E-CELL' What a non-descriptive, generic name! If I had thought of it I would have dismissed it as a 'battery thing' - not the name I'm looking for. Now... how to find one today?

PS. Found a part number... Type No. 560-0002, and a book reference...
https://books.google.com/books?id=x...onepage&q=E-cell timer "Figure 13-42"&f=false

 

[73's de Edd]

Sir BitHead. . . . . .

This must relate to your units intended use and still has a little variant in its construction.
Some accounts relate to a silver and gold plated electrode at each end of a capillary tube.
Others relate to a traveling of mercury from one electrode to the other, within the intermediate electrolyte gap.
(Akin to a " mercury plating " action with the mercury gradually tranferring between the cathode end to the anode electrodes end. )

Now I could also see an end switching action, if the electrode that the gap is moving towards has a SILVER needle point.
At the final end of travel, the center of the electrolyte gap is pierced by the needle point and a fierce amalgamation between the silver and touching mercury is made for a quite low resistance connection.
(Anyone that has ever rubbed mercury upon a silver coin, will attest to that effect . . . . .but alas . . .it oxidizes within a day or so . . . . and leaves the once ULTRA SHINY coin . . .looking ultra crappy.)

NEVER found any mention of your diode type / configuration of casing.
ADDENDA . . . .
Just now saw your reference to that configuration.
THOUGHT . . . . .want to REALLY stymie some people . . . just randomly throw in a resistor and this from power supply to ground on one of your schematics . . . .






The NAKED Curtis units that I was familiar with, looked like the very smallest magnetic reed switch that you have ever seen.

Probably the earliest mention of one company's intent for commercial use of their E-cell is here.



73's de Edd
.....

 

[(*steve*)]

And now we know why appliances fail 1 day out of warranty!