Question about the right transistors

Thread Starter

lubnaan90

Joined Jan 13, 2010
198
Can any one plzzzzzzz tell me, which transistors (Q1-Q10) are used in the "Oscillator, counter & decoder, and VU-LED" schematic , the picture is attached for reference . it seems the author forgot to mention the same in the Schematic .
 

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SgtWookie

Joined Jul 17, 2007
22,230
Can any one plzzzzzzz tell me, which transistors (Q1-Q10) are used in the "Oscillator, counter & decoder, and VU-LED" schematic , the picture is attached for reference . it seems the author forgot to mention the same in the Schematic .
You are "hijacking" someone else's topic. Please start a new topic instead of jumping in the middle of someone elses' topic, as it creates confusion.

To answer your question, you could use any general purpose PNP transistor. 2N2907, 2N3906, 2N4403, and a variety of others would work fine.
 
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Thread Starter

lubnaan90

Joined Jan 13, 2010
198
You are "hijacking" someone else's topic. Please start a new topic instead of jumping in the middle of someone elses' topic, as it creates confusion.

To answer your question, you could use any general purpose NPN transistor.
2N2222, 2N3904, 2N4401, and a variety of others would work fine.
thnx a lot 4 ur help , sorry abt the hijacking , will note ur point .
 

Audioguru

Joined Dec 20, 2007
11,248
The transistors on the schematic are PNP not NPN.
Their collector current is only about 12mA so any little PNP transistors will work.

Since the LEDs are multiplexed and are lighted for only 1/10th of the total time then they will be very dim.
 

Thread Starter

lubnaan90

Joined Jan 13, 2010
198
The transistors on the schematic are PNP not NPN.
Their collector current is only about 12mA so any little PNP transistors will work.

Since the LEDs are multiplexed and are lighted for only 1/10th of the total time then they will be very dim.
Thank you , can you plz recommend me any Specific PNP transistors i can use for the obove ,especially the ones which are easy to obtain .
 

Audioguru

Joined Dec 20, 2007
11,248
I would use 2N3906 or 2N4403 PNP transistors. If you are in Europe then you could use BC557 PNP transistors.
I do not know where you are so I don't know what you have available.
 

SgtWookie

Joined Jul 17, 2007
22,230
Sorry about that; AudioGuru is indeed correct; they are PNP not NPN. I edited my reply about that above to change part numbers.
 

Thread Starter

lubnaan90

Joined Jan 13, 2010
198
You are "hijacking" someone else's topic. Please start a new topic instead of jumping in the middle of someone elses' topic, as it creates confusion.

To answer your question, you could use any general purpose PNP transistor. 2N2907, 2N3906, 2N4403, and a variety of others would work fine.
It seems Sgtwookie corrected the Error , Noted the PNP transistors , Thnx .
 

Thread Starter

lubnaan90

Joined Jan 13, 2010
198
I would use 2N3906 or 2N4403 PNP transistors. If you are in Europe then you could use BC557 PNP transistors.
I do not know where you are so I don't know what you have available.
Thanks a Lot for also mentioning the European substitute of the above mentioned , as you see its really difficult to find "2N" & "PN" transistors here in Ukraine . Is there a European version for 2N3643 or PN3643 ?
 

bertus

Joined Apr 5, 2008
22,266
Hello,

In the old days some standard transistors where called TUN (transistor universal NPN) and TUP (transistor universal PNP) by elektor.
Here are the properties and some examples:







They used the following connections:



Greetings,
Bertus
 

SgtWookie

Joined Jul 17, 2007
22,230
Those would work. They are really meant for high voltage, but as long as you didn't need them to sink a lot of current, they could be used.
 

Thread Starter

lubnaan90

Joined Jan 13, 2010
198
2N3643
NPN
Vceo(min)=30
Hfe=100min/300max @ 150mA
Vce(sat)<=.22 @ 150mA
It=250MHz
Pd=350mW
TO-105
Obsolete

Replacement:
PN3643
Same as 2N3643, except:
Pd=625mW
TO-92
Datasheet: http://www.fairchildsemi.com/ds/PN/PN3643.pdf
Hi all, tried my best to find 2N3643 & the above mentioned Replacement PN3643, unfortunately couldn't find either of them .

can any of the below mentioned transistors be used as a replacement for the above ??

BC 327-40 , BC 328-25 , BC 337-40 , BC 338B , BC 517 , BC 547C ,
BC 557B , BC 557C , BC 639 , BC 807 , BC 817 , BC 847C , BC 848B,
BC 856B , BC 857C , BC 858B

2N 1893E , 2N 5401 , 2N 5551 , 2N 6073A , 2N 6400
 
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