Uses for 150-300 amp transistors?

They can be used as switches, but are also used as current controlled amplifiers - a small current into the base controls a much larger current through the collector and emitter, giving current and voltage gain, with a load placed between the collector and the supply.

Leon

Thanks.

In other words, two if these guys could be used to build a large single phase inverter, IF I find a way to control them properly with small current.

And six of them could be used to make a phase converter, if I also use at least 2 isolation transformers.

First pair -> phase 1 Second pair -> isolation transformer -> phase 2 Third pair -> isolation transformer -> phase 3

Phases 1, 2 and 3 could have one side of each joined together to form a neutral. All I have to make sure is that the signals to the transistors to switch current, should be offset by 120 degrees.

Is that right?

i

Something like that should be feasible. I'd try designing a low-power version first, with small Darlington transistors - less dangerous and expensive if you blow something up.

Leon

I cannot tell the difference (and will appreciate clarification), but some are indeed SCRs. I have no idea what is an SCR. I do not want to post model numbers, so as not to make an impression that I am trying to sell this stuff here.

i

It's a Darlington transistor pair designed to reduce the amount of drive current needed to control the main circuit. This one has a minimum gain of 75, so you need about 4 amps of base current to switch the main load. But note also that it has a forward voltage drop of 2 volts, so at full load (300A), it will be dissipating 600W of heat -- better have a serious heat sink attached.

These modules require s> After pillaging my UPSes, I am left with a few 150-300 amp

I still have heat sinks for them. Big heavy ones. Also very many fans.

thanks.

i

Got it. Thanks.

i

Aside from their suggestions--- an active load for testing car batteries. Maybe an induction heater, but that's a bit too high frequency probably. Control for DC motor (eg. electric vehicle). Or perhaps as part of a dynamometer (using it as a load on a generator).

Best regards, Spehro Pefhany

Indeed, a great way to load down alternators, etc. I have 2 such units at work...

I already have a real alternator testing kit (load bank), 12/24v, military surplus. Could not sell it on ebay and decided to keep for the future, just in case. Good for at least 100 amps.

i

Funny how I knew who posted this just by reading the text, before looking at the "From:".

It sounds like they are from a large online UPS. They're probably MOSFETs if they are black rectangular boxes or SCRs if they are have a giant threaded stud on them. What sort of UPS are they from?

Ignoramus17647 wrote:

From a big data general 60 amp UPS, 1 ferrups 3 kva UPS (to be converted to a meat smoker), and 2 clary 5 kva UPSes.

Some are IGBT, some are rectifiers, some are SCRs, and some are rectangular mysterious thingies that weigh over a pound each.

i

That datasheet is a bipolar transistor, with switching times (from

300A) up to 10uS. To me, it suggests a LF :On Tue, 15 Feb 2005 05:10:08 +0000 (UTC), Crow Leader wrote: : :> It sounds like they are from a large online UPS. They're probably :> MOSFETs if they are black rectangular boxes or SCRs if they are have :> a giant threaded stud on them. What sort of UPS are they from? : :From a big data general 60 amp UPS, 1 ferrups 3 kva UPS (to be :converted to a meat smoker), and 2 clary 5 kva UPSes. : :Some are IGBT, some are rectifiers, some are SCRs, and some are :rectangular mysterious thingies that weigh over a pound each. : :i : :>

:>

:> Ignoramus17647 wrote: :>> After pillaging my UPSes, I am left with a few 150-300 amp :>> transistors, rectifiers etc. I am curious, what could they be used :>> for, besides being in a UPS. I am especially curious about the :>> transistors. The rectifiers are of more obvious nature. I tried to :>> read about them, but it was some gobbledygook to me. :>> :>> One pdf for one such transistor is at :>> :>>

> :>> Would it be proper to say that this transistor is a remote switch? :>> (actuated from afar with a little current)? :>> :>> thanks :>> :>> i

I agree but high voltage, high energy projects are not for the beginners.