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Author Topic: What are these?  (Read 1496 times)

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Offline mstachoTopic starter

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What are these?
« on: July 22, 2011, 02:50:58 PM »
Hi everyone,

I just bought a "ginormous electronics surprise box" from electronics goldmine, and I have a few things that I've never seen before (and...about twenty 25MHz crystal oscillators...score!).  So if anyone knows what any of these things are, that'd be great:

- NEC-929 and NEC-920 (they look remarkably like power transistors, and since I only have the 929 and 920's, I'm guessing one is PNP and the other NPN.  Any other thoughts?  They are apparently obsolete, and Google has no clue!)

- a lot...seriously, a LOT...of SIP resistors.  This isn't so much a "what is it", since I know, but a "how do I read these".  For instance, I have one that says 8x-2-203.  I get that this means there are 8 resistors...each at 203 ohm?  And what about something like 10x-1-331?  What does the middle number mean? 

- Now these are a mystery, and yes I know that a picture would be best but I don't have a camera...sorry...here's my best description:

They are black devices, about 4mmx15mmx15mm, tapered at the top so they look like a trapezoid.  They have 4 leads, and an oval hole in the middle. The numbers K-2362 and 8817 are written on them, along with a symbol that LOOKS like a diode across two of the leads and another one that I've never seen before, sort of like a checkmark with an arrow coming out of it...

On the upside, I have about 20 of these, so once I find a use for them I'll never want them again :-P  I'm guessing they are rectifiers.

So, does anyone have any thoughts?

Oh, and anyone have any idea what I can do with a horizontal TV control IC? :-P

MIKE

Current project: tactile sensing systems for multifingered robot hands

Offline Soeren

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Re: What are these?
« Reply #1 on: July 22, 2011, 04:52:44 PM »
Hi,

- NEC-929 and NEC-920 (they look remarkably like power transistors, and since I only have the 929 and 920's, I'm guessing one is PNP and the other NPN.  Any other thoughts?  They are apparently obsolete, and Google has no clue!)
Use the diode check on your DMM to get the pin-out (like eg. b-c-e, if they're BjT's).
"Power transistor" doesn't say much about the housing? (TO-220, TO-3, or...?)


- a lot...seriously, a LOT...of SIP resistors.  This isn't so much a "what is it", since I know, but a "how do I read these".  For instance, I have one that says 8x-2-203.  I get that this means there are 8 resistors...each at 203 ohm?  And what about something like 10x-1-331?  What does the middle number mean? 
You'll not see a value of 203 Ohms.
203: 20 followed by 3 zeroes, a.k.a. 20kOhm
331: 33 followed by a single zero = 330 Ohm
The 8x and 10x should be obvious and I'd assume the 1 or 2 refers to whether they all have a common pin or that both ends of each resistor is brought out - but count the pins and/or dig out your DMM (which would have revealed the resistance values.
The 20k types may be handy, but the 330 Ohm will have less useability - I don't think I'll ever get to the bottom of my box of SIP arrays (around 4 or 5 kg of assorted values), but waste none, want none  ;D


- Now these are a mystery, and yes I know that a picture would be best but I don't have a camera...sorry...here's my best description:
What? A home without cell phones, webcams or any other piece of photographic repro possibilities - that's a rarity ;D


Oh, and anyone have any idea what I can do with a horizontal TV control IC? :-P
If it's a DIP, you could use it for a comb, a paper tack or as land fill... There's a reason for the low price on most of the "goodie bags".
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline mstachoTopic starter

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Re: What are these?
« Reply #2 on: July 22, 2011, 06:54:53 PM »
Howdy,

yup, sorry, it's TO-220.  Does that more or less imply that it's a power something or other?  Could be a regulator for all I know...

Oh I see, so those resistors are labelled something like capacitors... (actually, today I just learned that not all caps come with their rating printed nicely on them, and instead of have arcane things like 102k, which apparently means 10nF?  a 10, followed by 2 zeros, in picofarads, right?  then what's the K for? :-P)

Haha yes, my telephone is from the year 2005, so it came before cameras were commonplace :P I'm probably just going to take those weird looking things into the surplus store and ask tomorrow, although something tells me they are an arcane version of a Shottky transistor...only the four pins rather than three seem to not agree with me.

Thanks for the info!

MIKE
Current project: tactile sensing systems for multifingered robot hands

Offline Soeren

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Re: What are these?
« Reply #3 on: July 23, 2011, 08:24:29 AM »
Hi,

yup, sorry, it's TO-220.  Does that more or less imply that it's a power something or other?  Could be a regulator for all I know...
Yes, they're definitely not small signal transistors - industry never use  something that could be made cheaper (like a TO-92).
I don't think they're regulators. The numbers could point towards a complementary pair (i.e. one NPN and one PNP), but 10 seconds with the diode check will answer that and when you have the pinout, you can test their response (switching times) with a square wave signal and a 'scope.

It probably wouldn't be worth your while though, unless you have a fair amount of them - from time to time we all have to bin something for the lack of data and while it's annoying to get rid of what seems like functional components, it saves you time and worries. You don't have to toss them altogether though - perhaps in some years you stumble over the info.


(actually, today I just learned that not all caps come with their rating printed nicely on them, and instead of have arcane things like 102k, which apparently means 10nF?  a 10, followed by 2 zeros, in picofarads, right?  then what's the K for? :-P)
Eh? 10 followed by two zeros = 1000pF and that comes to 1nF in my book  :P
The "K" means 10% tolerance (on the value)


Haha yes, my telephone is from the year 2005, so it came before cameras were commonplace :P I'm probably just going to take those weird looking things into the surplus store and ask tomorrow, although something tells me they are an arcane version of a Shottky transistor...only the four pins rather than three seem to not agree with me.
Are the pins two at each side? (If they are, they may be some strange opto couplers, but that's a very uneducated guess - you really need even the cheapest cam or webcam - if someone in your circles discards a phone with a cam you could use that with a dummy SIM card, just for the cam.

I cannot imagine living without a cam - especially as my grandson just got a baby sister while on our vacation (she wasn't due for another two months) ;D ;D ;D
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline mstachoTopic starter

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Re: What are these?
« Reply #4 on: July 24, 2011, 07:33:53 AM »
If you were wondering, they are apparently an IR LED and an IR detector, that can be used as an encoder if you have reflective tape...or something like that.  The guy at the surplus store knew right away.  I'll look into getting that cam, and these things seem to be really useful for projects.  It's a good thing I have...like 20 of them :-P

MIKE
Current project: tactile sensing systems for multifingered robot hands

Offline Soeren

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Re: What are these?
« Reply #5 on: July 24, 2011, 09:51:49 AM »
Hi,

If you were wondering, they are apparently an IR LED and an IR detector, that can be used as an encoder if you have reflective tape...or something like that.  The guy at the surplus store knew right away.  I'll look into getting that cam, and these things seem to be really useful for projects.  It's a good thing I have...like 20 of them :-P

They're called Reflex Opto Couplers.
That was my initial guess due to the tapered shape you described, but I concluded, at that time, that you would have told us about any LED/photo transistor openings.

I have a similar type on my desk right now (for a servo/motor tool project), just awaiting me finding the 2mm nuts for the screws holding on to the PCB, but they're quite elusive little buggers ;(


In itself, it cannot be used as an encoder, as it need a patterned encoder disk, but I guess you knew that already ;D

If you need some encoder discs, I've made PDF's with, from 1 to 360 segments (with and without quadrature tracks) that prints extremely sharp, with no hint of ragged stair case edges (best on a LASER printer for longevity of course, or can be etched into PCB material). I have a couple I made for servos as well, for both 60° and 90° speed testing.
Just PM me with how many segments (and optionally what diameter) you need if you want any.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline Soeren

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Re: What are these?
« Reply #6 on: July 27, 2011, 09:22:35 PM »
This is an infrared detector? I think not!  ::) ::)
Well, I think I can live with your misconception  :P
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline TrickyNekro

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Re: What are these?
« Reply #7 on: July 28, 2011, 05:49:47 AM »
This is an infrared detector? I think not!  ::) ::)
Well, I think I can live with your misconception  :P

Basically it's a photoreflector.... Not clearly detector....

Hmmm... his misconception has a point though.... :P
For whom the interrupts toll...


P.S. I've been inactive for almost a year... Don't give promises but I'll try to complete my tutorials. I'll let you know when..

Cheers!

Offline Soeren

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Re: What are these?
« Reply #8 on: July 28, 2011, 07:08:16 AM »
Hi,

This is an infrared detector? I think not!  ::) ::)
Well, I think I can live with your misconception  :P

Basically it's a photoreflector.... Not clearly detector....

Hmmm... his misconception has a point though.... :P
Oh well... It should be clear to anyone that reads the entire thread before getting an itchy finger, that prior to Yuk's post, the term detector was only used by mstacho in the following context:
If you were wondering, they are apparently an IR LED and an IR detector, [...]
Just show me a single Reflex Opto Coupler/photoreflector that hasn't got a detector   ;)

If you want to nitpick about it... The entire unit detects material in front of it by infrared, so really... The entire coupler could be termed an infrared detector and it would still be a correct term - not that I'd call it that though, as that term is fairly wide and thus less precise.
Regards,
Søren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Please remember...
Engineering is based on numbers - not adjectives

Offline mstachoTopic starter

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Re: What are these?
« Reply #9 on: July 28, 2011, 07:21:45 AM »
Haha I guess it's important to be precise, especially when I'm trying to describe something without a picture.  A simple solution: next time I get something I don't know what it is, I'll find a camera and let the picture speak for itself  ;)
Current project: tactile sensing systems for multifingered robot hands

 


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