Transistor identification?

Help with identifying a TO-92 transistor?(at least I think it’s a 
transistor…)

Pretty vanilla-looking with National Semi logo. Marked:

NS 444
ST
13903

(The “NS” is the logo.)

Not enough 4’s to make up a standard 2N number, and 13903 looks like a date 
code?

Ideas?

Thanks,

> Help with identifying a TO-92 transistor?

A photo:

http://i.imgur.com/z78xG5D.jpg

On Sat, 05 Sep 2015 14:18:56 -0700, DaveC <not@home.cow> Gave us:

>> Help with identifying a TO-92 transistor?
>
>A photo:
>
>http://i.imgur.com/z78xG5D.jpg

  Put one of these in its place...

http://www.edn.com/design/test-and-measurement/4437360/How-to-measure-the-world-s-fastest-power-switch

  Just kidding, but hey...  check out the report anyway...

How's it measure?

(Or if it's dead, is there another one probably working that you can test?)

Tim

-- 
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

"DaveC" <not@home.cow> wrote in message 
news:0001HW.1B9B87FD00098A2611E4F83CF@news.eternal-september.org...
> Help with identifying a TO-92 transistor?(at least I think it&rsquo;s a
> transistor&hellip;)
>
> Pretty vanilla-looking with National Semi logo. Marked:
>
> NS 444
> ST
> 13903
>
> (The &ldquo;NS&rdquo; is the logo.)
>
> Not enough 4&rsquo;s to make up a standard 2N number, and 13903 looks like a 
> date
> code?
>
> Ideas?
>
> Thanks,
> 

> How's it measure?
> 
> (Or if it's dead, is there another one probably working that you can test?)
> 
> Tim

Dead. Other with identical markings measure as NPN. What else to determine 
from measurements?

Thanks.

On 09/05/2015 2:18 PM, Dave C wrote:
>> Help with identifying a TO-92 transistor?
>
> A photo:
>
> http://i.imgur.com/z78xG5D.jpg
>

Looks like a house number - made by National of course. House numbers 
can sometimes cross reference to other parts if you can find a master list.

How made the item in question.

John :-#)#

-- 
(Please post followups or tech inquiries to the USENET newsgroup)
John's  Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
                      www.flippers.com
        "Old pinballers never die, they just flip out."

> [Who] made the item in question. [?]
> John :-#)#
An American offset printing equipment company. It’s a paper/envelope feeder 
for a small offset presses. Extinct company.

I can say that the bandwidth requirement of the circuit is very small—DC-10 
KHz—and low current. Don’t know about gain.

Thanks.

On 05/09/2015 21:28, DaveC wrote:
> Help with identifying a TO-92 transistor?(at least I think it’s a
> transistor…)
>
> Pretty vanilla-looking with National Semi logo. Marked:
>
> NS 444
> ST
> 13903
>
> (The “NS” is the logo.)
>
> Not enough 4’s to make up a standard 2N number, and 13903 looks like a date
> code?
>
> Ideas?
>
> Thanks,
>

Or maker ST and date code for 1994 or 2004 or whatever goes with NS as 
plant/batch code for a particular decade

On 09/05/2015 11:05 PM, DaveC wrote:
>> [Who] made the item in question. [?]
>> John :-#)#
> An American offset printing equipment company. It’s a paper/envelope feeder
> for a small offset presses. Extinct company.
>
> I can say that the bandwidth requirement of the circuit is very small—DC-10
> KHz—and low current. Don’t know about gain.
>
> Thanks.
>

There are pretty simple circuit diagrams out there to measure gain if 
you have more transistors with the same markings.

One example:

http://electriciantraining.tpub.com/14179/css/14179_111.htm

The only other criteria are breakdown voltage and current. If it only 
drives other transistors and resistors to Vcc are over around 2K then it 
is likely 100ma or less.

If you know the Vcc you know the minimum breakdown voltage unless it is 
being used to control solenoids that have their own B+ source, then that 
voltage is your absolute minimum (times at least 2).

John :-#)#

-- 
(Please post followups or tech inquiries to the USENET newsgroup)
John's  Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
                      www.flippers.com
        "Old pinballers never die, they just flip out."

On 06/09/2015 07:05, DaveC wrote:
> I can say that the bandwidth requirement of the circuit is very small—DC-10
> KHz—and low current. Don’t know about gain.
>
> Thanks.
>

You could try a 2N3904 or other jelly bean type and see if the thing 
then works?

piglet