#2086

[@KeritechElectronics]

Looking at all those gold-plated parts... Pure joy! (and Usagi Electric got his tape reader working correctly, BTW)

[@gamerpaddy]

in a pile of e-scrap i once found a PSD (2 dimensional photo diode for position and focus sensing) with a huge 400mm² area, i think it was called DL400 from First Sensor.

[@pmcouto]

Not T1 - It's TI (Texas Instruments).

[@henrikstenlund5385]

This is interesting. Btw, not many know that ordinary point Ge diodes were painted black in the earlier decades as they were in glass envelopes. They were very light sensitive.

[@IMSAIGuy]

kzbin.info/www/bejne/kGTEiHSprMRnbsksi=rwyqKfaBP9nS_7Vh

[@outofturn]

I recognize some opt101 in that box; they are also friends of mine

[@analog_guy]

The mystery part is acting like I would expect a symmetrical photoFET or symmetrical photo-bipolar transistor to act.

[@johnlehman2157]

It would have been nice to seen an application for the device.

[@lmamakos]

Given the age of the part and the form-factor, this seems purpose made for paper tape readers. It predates mini-computers, but perhaps a high-speed tape reader for mainframes would be a fit for, e.g., loading bootstraps. It was the age teletypes that had mechanical readers and punches for storage and moving to optical reading would have been a natural thing to do at the time.

[@timflynn3218]

@@lmamakos Also used in auto-flushing toilets though those are larger; it senses the light being cut off, when you step away, it activated the valve.

[@rogergreenwood1536]

These things have clearly been around a along time, saw the data sheet was dated 1959!

[@smunaut]

Theses look like the ones @UsagiElectric is using in his paper tape reader for home made tube computer.

[@BrendaEM]

Have you a laser diode can opener? You know, for removing the output coupler? BTW, Usagi Electric recently made a tape-reader as well as repaired a Bendix computer, which used devices that looked a bit like those Photo Duo-diodes. Perhaps that is why they are so small in diameter.

[@IMSAIGuy]

i did open one: kzbin.info/www/bejne/bIKmdqKJr96jpaMsi=j0Bxch6k125eI24o

[@milantrcka121]

Looking up the datashet, the unit may be working up to some 8 kHz. Old enough, small enough and fast enough to serve as a sensor for (punch tape, punch card, ?????) Suspiciously similar to Usagi Electric tape reader sensors.

[@Manf-ft6zk]

Nice overview, I will have to set up a curve tracer myself, as an adapter to the scope in xy mode, or is a prepared set available? One might also present such a foot candle once for chip of the day. Some illumination from below, when walking not to fast so that the candles will not get blown out.

[@JaenEngineering]

So it's basically a phototransistor without the base connection.

[@stamasd8500]

not really because it's symmetrical, and the "base" is likely thick enough to not act as a base. It's probably no more a phototransistor than 2 regular diodes connected back to back make a transistor.

[@JaenEngineering]

maybe, although the datasheet does refer to it as an N-P-N device indicating a construction closer to that of a BJT than of a common anode dual diode... 🤔

[@ch2o2]

still don't know, what's the point of this video - what do you want to "teach" us? You don't really know, what the "strange parts" are for, okay ..more helpful would have been to show the people the setting of your measurements, the setting of the KOsz and how to make it operating in x-y-mode, whatever ...well, no hard feelings, just sayin'

[@JaenEngineering]

Completely pointless comment.

[@glasslinger]

@@JaenEngineering Not really. These were PHOTO devices! They respond to light! I would expect the photo sensitivity, photo linearity, photo speed, and wavelength sensitivity plot. These are parameters of photo devices. The reverse current plot is sort of "why" to me. None of the really pertinent parameters were demonstrated.

[@JaenEngineering]

@@glasslinger if you want that information about this specific component, go look up the datasheet.

[@bendunselman]

Give the experimentor some slack and freedom to experiment.

[@glasslinger]

@@JaenEngineering List the type numbers of the devices he demonstrated. DUH A lot of the time you don't have the part number or the datasheet is not found. You come across as a troll.