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A comment on “Space age electronics”: Inside a GE thin-film paperweight from the 1960s.

Re:“Space age electronics”: Inside a GE thin-film paperweigh... by jacquesm on Friday July 02, 2021 @06:52PM (#27717861)
Impressive how little that battery leaked over all those years. And funny how the transistors have an extra wire coming out of them, but those are all paired and run to the same terminal, I wonder what's up with that.

The beeper is one of those crystal (piezo) earphones with part of the bit that you would stick in your ear cut off.

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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by simonblack on Friday July 02, 2021 @07:16PM (#27718013)
Impressive how little that battery leaked over all those years

It was very likely one of batteries where each 'cell' looked like a block of compressed charcoal, about an inch or two square, with a strip of plastic around the edge. When I was a kid back in the 1960s, we used to pull these apart and throw the cells around like stones.

The most common size radio battery then was a 45 v battery, about 7" x 5" x 2" (IIRC) with a small socket in the top of it. https://www.flickr.com/photos/unclegal/31122957375

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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by tyingq on Friday July 02, 2021 @07:13PM (#27717994)
It would have been a zinc-carbon battery[1].

I'm also very surprised that it's not corroded.

[1] https://en.wikipedia.org/wiki/Zinc%E2%80%93carbon_battery

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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by kens on Friday July 02, 2021 @06:58PM (#27717900)
The two wires are probably for reliability and/or current capacity.
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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by jacquesm on Friday July 02, 2021 @07:02PM (#27717921)
Right, so they're either emitter or collector. Base would then be the single wire left over and the counterpart the big terminal bonded directly to the thin film circuit.

Beautiful bit of history, thank you very much for taking the time to do this one.

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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by morcheeba on Friday July 02, 2021 @11:53PM (#27719229)
But matching the schematic to the picture, the double wires are on the base. It makes me think it's a double-base transistor, but both bases tied together because they don't need two for this circuit.

If it was for reliability, I'd expect the emitter to also be doubled, but it has a single wire.

GE made the 3N36/37, but here's a datasheet for a similar part: http://bitsavers.org/components/ti/discrete/transistors/3N34...

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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by jacquesm on Saturday July 03, 2021 @02:49AM (#27719855)
That means it is definitely not for current. The current to the base would be negligible compared to the EC current.
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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by jandrese on Friday July 02, 2021 @09:44PM (#27718681)
I’m frankly shocked that a battery that looks like it is from the 60s still has charge enough to run a beeper.
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Re:“Space age electronics”: Inside a GE thin-film paperweigh... by kens on Saturday July 03, 2021 @12:02AM (#27719265)
The battery was dead and bulging open. I powered the paperweight from a power supply.
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