Can base amperage on an NPN be negative, and still work?

I think you are getting confused by datasheets. When it says '-24mA' for Ioh (for which there will be a Voh specified, incidentally) it means the current is going into the device (from an electron flow perspective).

Look at the current - from an electron flow view, the current will enter the emitter, move through the base and go through the output stage of the gate to the positive power supply.

So assuming you are running your logic from +5V, then it will operate a NPN just fine, and a 1k base resistor should be fine as well.

Cheers

PeteS

Some gate specsheets treat positive current as flowing into the output

-- current the gate sinks. Negative current would be out of the gate into a load, as your transistor. This is because TTL and DTL gates were much better at sinking than they were at sourcing. If your gate can deliver 24 mA in the high state, you should be in good shape.

In message , dated Sun, 3 Sep 2006, Mr. J D writes

Would you please try to write 'current' instead of 'amperage'? Do you say 'meterage' instead of 'height' or 'hourage' instead of 'time'?

The minus sign indicates that the current flows OUT of the AND gate package, which is just what you want to turn on your NPN transistor.

Current isn't positive' or 'negative', it flows either 'in' or 'out'.

Thanks for the clarafication on those datasheets. BTW, amperage is a correct EE term. Amperage as a noun (SOMETHING, place or thing) is the strength of current measured in amps. My use of the word was 100% grammatically correct.

But if you are excessively pedantic people will think you are a foreigner. For example, terms like 'potential amperage' seem oxymoronic.

Woop-de-doo ;-)

...Jim Thompson

In message , dated Sun, 3 Sep 2006, Mr. J D writes

NO, it isn't. You cannot rust general-purpose dictionaries for advice about technical terms.

I detected arrogance in your posts before. Now I know I wasn't mistaken. It doesn't go down well on this newsgroup.

Doesn't prevent those religious people from using their rusty books.

Or are you saying they are unrustable?

DNA

Mr. J D wrote: [snip]

The bow of a boat may correctly be called the front, according to the dictionary definition of 'front'. But sailors will still look at you funny unless you call it the bow.

Tim

Have you ever written "voltage" rather than "potential" or "EMF"?

They believe in magic words like 'Iscariot' - although there is no such word.

In message , dated Sun, 3 Sep

Quite. Then there are irreligious books, by Salmon Rusty.

Unrustworthy. Waste of oxygen. (;-)

In message , dated Sun, 3 Sep 2006, Tim Auton writes

Actually, they look at you sternly.

Personally, I don't much care if someone says 'Amperage is grammatically correct'. It's *incorrect* in engineering. The term is 'current'. Using the term amperage marks you (or anyone else) as someone who "doesn't know the lingo", and by connotation "probably doesn't know the subject".

Please link a datasheet that states something like 'Ioh (amperage from the output pin when high)' - Every one I've read (which is easily in the thousands and probably in tens of thousands, as it probably is for most here) shows it as 'output current in the high state', except for the 'literal translations from Japanese' datasheets which one may still occasionally find (literal translations from any language to another is always a source of mirth for engineers). See the current NJR databook for many a laugh.

To almost quote AoE: 'Amperage is strictly bush league' (As is wattage)

Cheers

PeteS

In message , dated Sun, 3 Sep 2006, Don Foreman writes

Yes, but language doesn't have to be consistent. The term 'voltage' is perfectly normal and used in writings of all levels of formality. But 'amperage' isn't.

How do you feel about 'ohmage' instead of 'resistance'? I've even heard (but not seen written (yet!), 'puffage'.

As someone who spent 12 years in the R.N., I can say we would look at them in a sharp way.

On that front, you can call it a door (grammatically correct) although it's a hatch (yes, even the ones you walk through) or a wall when it's a bulkhead. Indeed, as one who worked on aircraft and therefore was not saddled with being on the ship except when it actually deployed, we took great pleasure in deliberately referring to the bow as 'the sharp end' and the stern as 'the blunt end' which really annoyed the 'general service' officers.

Cheers

PeteS

The suffix -age derives from vulgar Latin -aticum meaning stuff. So ampere-age is understood to mean amount of the amperage stuff. I have no problems with milliamperage or microamperage...it is actually fairly proper. But to use amperage in the context of logic circuits is like expressing Vcc as 0.005KV.

I prefer 'pointy' and 'blunt'.