« previous next »
Pages: [1]   Go Down

Author Topic: Unknown part  (Read 3098 times)

0 Members and 1 Guest are viewing this topic.

Offline shock__Topic starter

  • Newbie
  • Posts: 2
  • Country: de
Unknown part
« on: September 15, 2018, 12:39:24 pm »
Hey there,
I'm currently in the process of partially reverse engineering a stamped card reader and stumbled upon a part I can't exactly verify.
The PCB the part is on can be dated to early/mid 70s and was at least designed in Germany.

Any ideas?
« Last Edit: September 15, 2018, 12:41:17 pm by shock__ »
Logged
 

Offline madires

  • Super Contributor
  • ***
  • Posts: 7765
  • Country: de
  • A qualified hobbyist ;)
Re: Unknown part
« Reply #1 on: September 15, 2018, 01:54:07 pm »
An image with a higher resolution would be helpful. At first glance it looks like a broken resistor. Have you checked it with a DMM?
Logged
 
The following users thanked this post: Beamin

Offline Quarlo Klobrigney

  • Frequent Contributor
  • **
  • Posts: 967
  • Country: pt
  • This Space For Rent
Re: Unknown part
« Reply #2 on: September 15, 2018, 02:17:35 pm »
Looks to be a diode, which says 141, 242, 343, 747. Poor resolution an poor colours. Please resend.
Logged
Voltage does not flow, nor does voltage go.
 

Offline shock__Topic starter

  • Newbie
  • Posts: 2
  • Country: de
Re: Unknown part
« Reply #3 on: September 17, 2018, 04:34:34 pm »
Here's a better picture, a friend of mine who often works with vintage (analog) electronics told me it's a "flyback/recovery diode" (Freilaufdiode in German) which would make sense as it's connected to a relais.
Picture was taken with flash activated on my smartphone (which is the best I can offer). Size is slightly smaller than a common leaded resistor for signals (0207?).

Also attached is the (partial, temporary) schematic I got so far, U1 and U2 are the parts in question, the green line underneath corresponds with what I interpret as the "white marker" for the cathode.

« Last Edit: September 17, 2018, 04:46:25 pm by shock__ »
Logged
 

Offline PA0PBZ

  • Super Contributor
  • ***
  • Posts: 5127
  • Country: nl
Re: Unknown part
« Reply #4 on: September 17, 2018, 05:49:09 pm »
Oyes that's a diode  ;)

An 1N400X will do fine here.
« Last Edit: September 17, 2018, 05:53:04 pm by PA0PBZ »
Logged
Keyboard error: Press F1 to continue.
 

Offline Quarlo Klobrigney

  • Frequent Contributor
  • **
  • Posts: 967
  • Country: pt
  • This Space For Rent
Re: Unknown part
« Reply #5 on: September 17, 2018, 06:38:41 pm »
Maybe a 1N141. The 1984 Fairchild Databook says that a direct sub is the 1N4148.
See another version in the datasheet here:
« Last Edit: September 17, 2018, 06:42:13 pm by Quarlo Klobrigney »
Logged
Voltage does not flow, nor does voltage go.
 

Offline gbaddeley

  • Regular Contributor
  • *
  • Posts: 205
  • Country: au
Re: Unknown part
« Reply #6 on: September 21, 2018, 06:58:37 am »
Quote
Maybe a 1N141.
Brown Yellow Brown = 141 ?? :-\
« Last Edit: September 21, 2018, 07:02:02 am by gbaddeley »
Logged
Glenn
 

Offline Beamin

  • Super Contributor
  • ***
  • Posts: 1567
  • Country: us
  • If you think my Boobs are big you should see my ba
Re: Unknown part
« Reply #7 on: September 21, 2018, 03:26:02 pm »
Why do they have U2(diode?) across  74LS00N a nand gate? Wouldn't that feed back on it self? If the | on the schematic indicates the neg side of the diode wouldn't that mean when the first (top) pin is high it and the bottom pin is high it sends out zero. But if you put a diode on the output as a wire/bridgeto input 2 it can't turn on because it would then see that pin 1 and 2 are different? I'm confused it seems like that set up would make it never turn on.

What does that circuit do?

Datasheet of that part:
http://ecelabs.njit.edu/student_resources/datas/74ls00.pdf
Logged
Max characters: 300; characters remaining: 191
Images in your signature must be no greater than 500x25 pixels
 

Offline Quarlo Klobrigney

  • Frequent Contributor
  • **
  • Posts: 967
  • Country: pt
  • This Space For Rent
Re: Unknown part
« Reply #8 on: September 21, 2018, 08:25:08 pm »
Because it's not a multiplier band.

Quote from: gbaddeley on Today at 01:58:37
Brown Yellow Brown = 141 ?? :-\
« Last Edit: September 21, 2018, 08:30:47 pm by Quarlo Klobrigney »
Logged
Voltage does not flow, nor does voltage go.
 

Offline Quarlo Klobrigney

  • Frequent Contributor
  • **
  • Posts: 967
  • Country: pt
  • This Space For Rent
Re: Unknown part
« Reply #9 on: September 21, 2018, 08:34:18 pm »
Why is if followed by the?

It's all about the reference. I don't see a schematic.

Quote from: Beamin on Today at 10:26:02
Why do they have U2(diode?) across  74LS00N a nand gate?
« Last Edit: September 22, 2018, 12:34:09 am by Quarlo Klobrigney »
Logged
Voltage does not flow, nor does voltage go.
 

Offline gbaddeley

  • Regular Contributor
  • *
  • Posts: 205
  • Country: au
Re: Unknown part
« Reply #10 on: September 24, 2018, 07:32:19 am »
Quote from: gbaddeley on September 21, 2018, 06:58:37 am
Quote
Maybe a 1N141.
Brown Yellow Brown = 141 ?? :-\
Quoting my own post, the '??' mean I am questioning: Was it identified as IN141 by reading the colour bands?
Logged
Glenn
 
Pages: [1]   Go Up
« previous next »

Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf

 


EEVblog Main Site EEVblog on Youtube EEVblog on Twitter EEVblog on Facebook EEVblog on Odysee