pucho812

What transistor is this?
« on: November 30, 2019, 06:26:36 PM »
Looking at the photo looks like a national but looking up the numbers 417 shows up as bd417 pn3568 shows up as a transistor as well.

I am thinking pn3568, but a second opinion is good.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.


pucho812

Re: What transistor is this?
« Reply #1 on: November 30, 2019, 06:59:51 PM »
sorry for  fuzzy photo....

top numbers are 417
then a PN
then 3568
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Brian Roth

Re: What transistor is this?
« Reply #2 on: November 30, 2019, 07:02:23 PM »
I definitely vote for pn3568.....I seem to recall "PN" numbers being same/similar as "2N".  471 would be a date code.

Bri

EDIT...my memory may be faulty, but I think a "PN" transistor may have a different pinout compared to a "2N".
« Last Edit: November 30, 2019, 07:43:16 PM by Brian Roth »
Brian Roth Technical Services
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http://www.BrianRoth.com
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pucho812

Re: What transistor is this?
« Reply #3 on: November 30, 2019, 08:50:57 PM »
I definitely vote for pn3568.....I seem to recall "PN" numbers being same/similar as "2N".  471 would be a date code.

Bri

EDIT...my memory may be faulty, but I think a "PN" transistor may have a different pinout compared to a "2N".

yes, I was thinking pn3568  as well but got confused because of the 417 being first...
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Brian Roth

Brian Roth Technical Services
Salina Kansas, home of the best vinyl on the planet!

http://www.BrianRoth.com
recordingservicesandsupply.com/
www.qualityrecordpressings.com/
store.acousticsounds.com

pucho812

Re: What transistor is this?
« Reply #5 on: November 30, 2019, 09:35:23 PM »
https://www.mouser.com/ProductDetail/Central-Semiconductor/PN3568?qs=sGAEpiMZZMshyDBzk1%2FWiw99kSkYzPxmOHeqHB5vyQ0%3D

Seems that it may be  "end of life".

Bri

thanks Brian. I am sure it is, but there is always the occasional stash or NTE part...
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

JohnRoberts

Re: What transistor is this?
« Reply #6 on: November 30, 2019, 09:51:11 PM »
I vote for national semi PN3568... there are data sheets around the internets...

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

RuudNL

There is a solution for every problem!

http://www.vansteenisaudio.nl

PRR

Re: What transistor is this?
« Reply #8 on: December 01, 2019, 11:17:50 AM »
> I seem to recall "PN" numbers being same/similar as "2N".  .... I think a "PN" transistor may have a different pinout compared to a "2N".

"PN" was a standard 2N metal-can part reissued in a plastic blob. The die inside should be the same. The pinout depends on the package; the two types wire the die to the legs different. But of course you always look-up the pinout for the part in hand, and verify it with ohmmeter, or now one of those $13 testers.

CJ

Re: What transistor is this?
« Reply #9 on: December 01, 2019, 10:32:00 PM »
that's right the old motorola cans like the 2N3440

i was wondering why I-c was so hi
If I can't fix it, I can fix it so nobody else can!
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clintrubber

Re: What transistor is this?
« Reply #10 on: December 04, 2019, 09:58:43 AM »
You was just curious to the transistor-type, or does it need replacing... or just for circuit-tracing?

JohnRoberts

Re: What transistor is this?
« Reply #11 on: December 04, 2019, 10:22:09 AM »
that's right the old motorola cans like the 2N3440

i was wondering why I-c was so hi

The  3568 is what is called medium power. While rated for 1A of collector current the PN (plastic) package has a thermal resistance of 200'/W junction to ambient. A maximum 150' junction temps suggest that 1A collector current is not available with much (any?) voltage drop.

Further, the beta is only specified at 150mA. Another hint this is not a 1A pass element device. Perhaps used as a saturated switch for a major fraction of one amp (like relay/lamp driver).

I have seen medium power transistors used for low noise applications way back when (due to their low Rbb to handle peak current), even though they make no such low noise claims. As I recall such users had to sort through numbers of these to select out devices with significant process noise. 

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

pucho812

Re: What transistor is this?
« Reply #12 on: December 04, 2019, 01:49:46 PM »
You was just curious to the transistor-type, or does it need replacing... or just for circuit-tracing?

these transistors are all over relay cards in a desk owned by a studio in town.  The cards themselves are usually duel channel with 2 x relays and about 6 of these transistors on them, 3 per channel. While I do have a card that stopped working we were able to replace it with a spare card for now.  I don't have a schematic but will get to tracing one in the future...  At the immediate, I was just confirming what transistor this could be as both sets of numbers came up as a possible transistor and the desk is over 30 years of age and still holding up quite well.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

clintrubber

Re: What transistor is this?
« Reply #13 on: December 04, 2019, 02:28:58 PM »
these transistors are all over relay cards in a desk owned by a studio in town.
Ok, so they're not in any signal path providing eventual ehh, mojo...  :)

... at least I haven't seen any company promoting their gear by claiming sonic benefits of the utility components around the signal path (as long as they're transparant and not introducing any disturbances when doing their utility-thing)

pucho812

Re: What transistor is this?
« Reply #14 on: December 04, 2019, 02:34:15 PM »
Ok, so they're not in any signal path providing eventual ehh, mojo...  :)

... at least I haven't seen any company promoting their gear by claiming sonic benefits of the utility components around the signal path (as long as they're transparant and not introducing any disturbances when doing their utility-thing)

No, no mojo in these just working the relay cards that switch things...😂
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

JohnRoberts

Re: What transistor is this?
« Reply #15 on: December 04, 2019, 02:40:31 PM »
No, no mojo in these just working the relay cards that switch things...😂
sounds like a good application for a GP medium power transistor. 

As I mentioned relay/lamp drivers are typical applications.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

clintrubber

Re: What transistor is this?
« Reply #16 on: December 04, 2019, 02:46:24 PM »
No, no mojo in these just working the relay cards that switch things...😂
I heard that for a very limited time, a special run could be ordered of these relay cards, using metal can types for these switching transistors... not hard to imagine that these are the ones you want  :o ;D 8)

moamps

Re: What transistor is this?
« Reply #17 on: December 04, 2019, 03:33:50 PM »
.... the PN (plastic) package has a thermal resistance of 200'/W junction to ambient...

I've always wondered why  fully metal TO39 package (2N3440 mentioned for example) is rated to so poor/high RθJA (175°C/W to 220°C/W).

pucho812

Re: What transistor is this?
« Reply #18 on: December 04, 2019, 06:58:22 PM »
good question...
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.


 

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