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Modern Replacements for PN2907A and PN2222A

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Souper man

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I was wondering what are some modern replacements for 2 common transistors that I use:
PN2907A
PN2222A

They must be non-amplifying, TO-92 package transistors.

THANKS
 
What's wrong with these? Not expensive enough, too easy to find? Maybe they are too hard to burn up? Not sure what sort of improvement you are looking for in a general purpose transistor. These have been around a long time for a reason.
 
Audioguru said they were old transistors, and I was wondering if they had newer counterparts
 
I think your request for a "non-amplifying transistor" reveals quite a bit about your grasp of the requirements for such a part.
 
A BC337 is about the same as a 2N2222A or PN2222A, and a BC327 is about the same as a 2N2907 or PN2907A, but they are in TO-92 cases.

The 2N4401 NPN and 2N4403 PNP are almost the same (only 600mA max). They are also in TO-92 cases.
 
We had a thread a while back about why there are at least 3 basic versions of many transistors.

There is the US version, the British version, and the Japanese version.

They all work. Some of the me-too versions are better in some ways then the originals.
 
If you're not too fussy about a particular specific, most of the time you can substitute any NPN or PNP transistor for any other of the same type with similar specs and be OK. This is especially true if your frequency and power requirements are low.
 
Papabravo said:
I think your request for a "non-amplifying transistor" reveals quite a bit about your grasp of the requirements for such a part.

I would agree!

I would suggest a short length of copper wire would work just fine as an non amplifying transistor:rolleyes:
 
Remember when a good audio amplifier was called, "A piece of wire with gain"?
 
audioguru said:
Remember when a good audio amplifier was called, "A piece of wire with gain"?

hi agu,
I too remember that piece of wire, about 100ft of aerial wire;)

Could just get long wave BBC, on 1500mtr wavelength, on a good day.

These days the 'whisker' is on me, not the 'crystal'!
 
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audioguru said:
A BC337 is about the same as a 2N2222A or PN2222A, and a BC327 is about the same as a 2N2907 or PN2907A, but they are in TO-92 cases.

The 2N4401 NPN and 2N4403 PNP are almost the same (only 600mA max). They are also in TO-92 cases.
That's fair enough in audio applications but not much use if you're buiding a transmitter, the BC337 and BC327 have a GBWP of only 100MHz, whilst the 2N2222A has a GBWP of 300MHz and the 2N2907 has a GBWP of 250MHz.

This proves the point that you need to check the datahseet for the transistors you're substituting. You need to consider things like gain, noise maximum current and voltage and GBWP. Some of these specifications are more important in some applications than others.
 
If you're concerned about max current and voltage then you also have to be careful with max dissipation, that is sometimes overlooked (until you start to smell something burning)
 
I know the smell of a plastic cased transistor burning, but I can't remember if a metal case transistor makes any kind of smell as it melts inside.
 
Thinking about the smell of burnt electronics :)

I recall the EE types stinking the place up with backwards caps and the like. At times they used current to zap a short on internal layers. Do not recall if that ever caused a stink.

Does anyone do this or know what current and voltage is used. Do not have a need, just curious.
 
The die is still potted in the metal case so I think it would still smell if it burnt out.
 
In my high school electronics course I'd crank the lab bench supply up to the max (300v) and then turn on the power at the other end of the table. BANG!
 
Many moons ago, when I was studying electronics at college, our tutor purposly connected 200V 470,000uf electrolytic the wrong way round on a 400V DC 30amp supply... :eek:

KABOOOOOM!!! :D

It was raining aluminium foil and bits of electrolyte coated paper for what seemed like 10 minutes! :eek:
 
That's 18.8kJ, somehow I don't believe you!

Are you sure it wasn't a 20V 470,000:mu:F or a 470:mu:F 200V capacitor?
 
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