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Eagle Issue w/Transistor

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Maybe i am confused or something but something does not make sense here with Q1 and Q2. For example if one looks at Q1, on the schematic the emitter is connected to R11 and the emitter of Q2.
On the other hand if one looks at the board drawing, which is attached below it seems quite the opposite with the collector. Even if i was to assume that orientation is correct , transistors T1-T4 are even different.
I would appreciate it if someone could explain this to me a bit, or at the least explain to me Eagles orientation of these transistors.

**broken link removed**[/URL][/IMG]

Thanks
Pete
 
Hi,
Is R11 next to R9? That's correct if it is. I've seen the datasheet of 2N5771. It is EBC when the flat surface is facing you and the leads are pointing down. I don't know about T1-T4.
 
look at the part in the library editor. It's pretty common for eagle libs to have flat out wrong parts.
 
Without looking at the schematic, it is hard to tell, but it looks like you have a routing problem with T1 as I see no connection to the base (pin 2?). There appear to be several parts that are not routed yet unless we can't see the upper layer. What types of transistors are T2 & T2? Are they both the same or different types?
 
Oh, I forgot, also there are different packages for a given transistor with different pinouts (2n2222 has several, for example). As I recall, there are transistors in the eagle libs that don't specify the actual package.
 
kchriste said:
Without looking at the schematic, it is hard to tell, but it looks like you have a routing problem with T1 as I see no connection to the base (pin 2?). There appear to be several parts that are not routed yet unless we can't see the upper layer. What types of transistors are T2 & T2? Are they both the same or different types?

At first I just thought the designer didn't hit ratsnest before exporting the image, so the bottom-layer ground polygon was never drawn, but I guess that doesn't make sense because there are other things which make me think either there is at least one more layer not shown or the layout isn't finished yet and the Unrouted layer is turned off.

- D2 connects to nothing.
- 8 looks like it has pins 2 and 3 directly connected to each other. I don't know enough about transistors to say that this is never done, but I can't think of a reason--especially not without knowing what T8 is.
- Q1's base connects to nothing. If the Theory of the Not-done Ratsnest is true, then Q1's base could connect to the local polygon, but that doesn't connect to anything else either.
- The line from R8 and R9 doesn't appear to quite reach R4.

Is this the result of Eagle's autorouting? If so, it might not have been able to complete the job.


Torben
 
First i should say there are a few airwires that have been removed to make the image easier seen. Anyway i have included another pcb below with the air wires and schematic that are complete.
Ignore the diodes...please..for now
The problem it seems is that Q1 and Q2 have the emitter and collector flipped..or maybe i am flipped.

Please help ..thanks , Pete

**broken link removed**

**broken link removed**

Circuit is courtesy user Roff

Thanks again
 
The problem it seems is that Q1 and Q2 have the emitter and collector flipped..or maybe i am flipped.
They look correct to me:
**broken link removed**
Now the other NPN transistors (T1-10) I can't tell what part number they have from the images you posted. Maybe they are the "backwards" ones?
 
If you look at transistor T1-T4 you will see that the emitter is the most right transistor pin at the pcb schematic ? Right
If you look at Q1 and Q2 the emitter is the left most pin ? ??

Why opposite ?

Pete
 
Why opposite ?
Because they are different types of transistors. Not all TO-92 transistors have the same pin out.
 
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