looking for a transistor

It can be done. It is only a 90 degree rise from the case to the outside of the TO-18. If the ambient is room temperature and the heat sink is infinite and the transfer is a good heat pipe, it would be just fine.

On the other hand, you could use the plastic packaged one in a heat sink and do a little better.

I am really glad that I don't believe him about designing stuff for the military. I'd rather he worked for the enemy.

Where do you get that figure from ?

The data I posted shows a thermal resistance fom junction to case of

Graham

There is no "let's", idiot. You are all alone, and wrong.

God's design + wrong data = Eeyore

If you were any more retarded someone would have to spoon feed you your dinner as well, idiot.

You're an idiot.

Trying to deny the facts on the datasheet again ?

Do you get a kick out of being WRONG all the time ?

Graham

Why would you build any amplifier where you intended to **overload* * the transistors ? It's important to operate devices with their SOA. And TO-220s are no different in that regard.

Graham

with

then?

Are they? TO-220 power devices work quite nicely in a 10W class AB amplifier. Do you think I could use the ZTX parts for the same application?

Tim

-- Deep Fryer: A very philosophical monk. Website @

Just for fun:

A typical TO-92 has 18 mil leads. If pure copper, that corresponds to just about 400 K/w per inch of lead length, per lead.

John

And they're not copper of course, so more than that.

Graham

I have built Class AB audio line driver stages using TO-92 BC184s and BC

If you did you'd be outside their SOA wouldn't you ?

Are you even thinking about what you say ? Do you know what SOA is ?

Graham

Maybe a good reason to mount them close to the board. A 0.1 inch long copper collector lead soldered into a large copper area can suck quite a bit of heat.

Stop stalling, you know very well they have a nearly square SOA.

Do you think I could use the ZTX parts for the same application?

Tim

-- Deep Fryer: A very philosophical monk. Website @

Which application ?

If they don't have the required dissipation, obviously not. Are you COMPLETELY stupid ?

Graham

Uh? You quoted the very words "ten watt class AB amplifier".

No, but you must be. We began this subthread with "I wish they made TO-220's that could handle overload". You flat out *denied* that there was any advantage to TO-220 devices in terms of power handling. So, I proceeded to give you a very specific example where that power capacity *would* matter. You responded, utterly confused, as if the sky had just fallen.

So tell me, IS there any advantage of E-line vs. TO-220 devices with respect to overload capacity (the ability to withstand continuous dissipation of, say, 10W or more)?

Tim

-- Deep Fryer: A very philosophical monk. Website @

NO !

I denied there was any advantage in terms of *OVERLOAD* handling. There is a HUGE difference between an 'overload' and long-term power handling.

Personally I don't *overload* transistors and I suggest you don't either unless you want failures.

Stop talking nonsense.

Graham

If you ever followed your own advise, you could never speak, write or type again. :(

-- Service to my country? Been there, Done that, and I've got my DD214 to prove it. Member of DAV #85.

Michael A. Terrell Central Florida

IDIOT

Yes, you are but it doesn't stop you form posting your drivvel. :(