Exchanging Parts Any one? I have lots of NPN, and I want some PNP like Tip145, Tip146, Tip147

One is not "better" than the other, but rather some applications call for NPN, some for PNP, and others require both. It depends what you're doing.

I wonder what wiki?

Depending on the wiki, perhaps the reference was historical; in the late

1950's -> early 1960's there was a lot of buzz about new 'mesa' NPN transistors which had hugely improved characteristics over previous mostly PNP processes.

Michael

Stille there are some small differences. Compare the end 70's transistors like BC547/BC557, and you will see that the NPN one usually has somewhat more bandwidth or other better parameters. I was taught that the NPN's tend to be (this is not a rule) a little more robust when you overload them. I haven't check the latest transistors.

Pieter

Ok, you all are smart. I was just using Wiki's stupid editor as a reason to get you to exchange stuffs...heehe. You know what I mean? The American Way. To be honest with you I don't like NPN, most of them takes so much Base current which means you have to buy a big resistor if you deal with the final output.

If the base current bothers you, pick up some MOSFETs, they're voltage driven and require no appreciable base current, you can turn them on easily with what will conduct through your body.

'Charged' words to be written for an audience enduring a cold, lonely, snowy winter.

Michael

MOSFET's die so easily, do google search on "Mosfet failure" you will see what I mean. It depends on the application really, MOSFET's are still good for other applications but not to drive heavy duty coils that has a AC kick-back effect. If MOSFET's were used in your vehicle, 99% of the traffic will stop moving.

Have you noticed that it has the latch effect? Just like you toggle the switch on and off.

"Camsid" wrote in news:fp67no$vij$ snipped-for-privacy@aioe.org:

Many are intended for switching high current loads, and have protection diodes built in, and can have more added. I'm fairly sure a varistor or zener will punish any errant spikes forcibly enough, too.

That might be a problem, not sure though, I don't know enough about them to comment more.

Lostgallifreyan wrote in news:Xns9A46C0072A06Czoodlewurdle@140.99.99.130:

Further to this, I've seen Robin Bowden's small video of a laser diode module he zapped with a gas ignitor. All that happened was the laser diode flashed as the ernergy hit it. He protected it with no more that a zener and a low ESR ceramic cap, and maybe a resistor, so if you can protect a laser diode that way, against strong direct repeated hits, I GUARANTEE you can protect a MOSFET.

Bullshit. I've been using MOSFETs for years, failure is very rare. They

*are* used in my car as the injector drivers, as well as many other cars. They're also used all the time in industrial motor drivers, coil drivers, high powered tesla coils, virtually everywhere. They're very durable parts so long as you protect them from ESD and use them within their specifications.

Absolutely agree - I use MOSFETs in practically all of my designs for industrial and commercial applications and produce several hundred units annually that work in environmentally unsavory conditions. Due to good design and ensuring they work within their specs (and use only quality branded devices) I have had 0% failure in over 3 years.