Question about Bipolar NPN Transistor -2N2222

Thread Starter


Joined Jul 28, 2014
HA! Finally figured out why I'm so confused. But thank you for everyone's input.

I have a P2N2222A and the book is describing a 2N2222

I looked up the book Errata and found

Some versions of the companion kit from RadioShack (Component Pack 1) may include a P2N2222 rather than the 2N2222.

The 2N2222 or PN2222 or PN2222A will have its flat side on the right, but if you happen to have the P2N2222 or P2N2222A or any other transistor whose part begins with P2N2222, you must reverse it so that the flat side is on the left (viewed from above). This affects Experiment 10 as well as any other experiment that calls for the 2N2222.

Note from the Author or Editor:
Add this important text as an additional paragraph to the caption for Figure 2-84. There is sufficient white space to allow this:

Beware of confusion using part numbers P2N2222 and P2N2222A. Some were made by On Semiconductor and may be supplied by Radio Shack. Their pins are reversed, so that the part should be used with its flat side on the left, not on the right as in the diagram above. The diagram above is correct for parts such as 2N2222, PN2222, or PN2222A, but not for parts with numbers begining P2N


Joined Nov 7, 2013
Use the small filament. ~2.5ohms cold / 600ma

The big side draws over 2 amps which may be good for testing also..


Joined Jun 17, 2014

Try a different transistor anyway, like the 2N440x versions. They are better than the 2N2222 type anyway.

Also, if the picture you take comes out blurry, take another picture maybe from a little farther away. You dont convey any better information if nobody can see the parts in your picture.

Thread Starter


Joined Jul 28, 2014
Thanks everyone for the help. My take aways from this are.

1. The book isn't always accurate make sure you check the errata before thinking your nuts.
2. Transistors are not all made to have the pins in the same direction check the data on the transistor and make sure your looking at the correct data sheet for the transistor your using (this probably applies to all components)