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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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16th Mar 2017, 6:36 pm | #1 |
Octode
Join Date: Nov 2013
Location: Penrith, Cumbria, UK
Posts: 1,993
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Huge NPN transistor
A friend of ours has this souvenir from his days as an electronics engineer and i thought I'd like to share it here as I have never seen such a large device before. No doubt there's a few members who can tell us a fair bit about these big transistors.
Andy |
16th Mar 2017, 6:41 pm | #2 |
Guest
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Re: Huge NPN transistor
That's an IGBT, a mosfet NPN darlington, bloomin' huge thing. You could do the same now with a few MOSFETS in parallel. I wonder how big the chip inside is?
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16th Mar 2017, 6:47 pm | #3 |
Octode
Join Date: Nov 2013
Location: Penrith, Cumbria, UK
Posts: 1,993
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Re: Huge NPN transistor
It does make the mind boggle, 600A at 400V! I think len said it was used as part of an emergency PSU in a big phone exchange, if I understood him right.
I had this flight of fancy of some mad person getting a couple and using them as a high power single ended output stage. What a USP that might have been. switch the thing on and all the lights in town go dim................... Like i said completely mad and I apologise for that. A |
16th Mar 2017, 8:16 pm | #4 |
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Re: Huge NPN transistor
A mere four of these http://uk.farnell.com/ixys-semicondu...64p/dp/2674784 amazing how technology has advanced.
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16th Mar 2017, 8:27 pm | #5 |
Pentode
Join Date: Oct 2016
Location: Maldon, Essex, UK.
Posts: 182
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Re: Huge NPN transistor
GE’s variable frequency drive can deliver up to 15 MW with just 18 IGBTs.
http://www.gepowerconversion.com/sit...rochure_EN.pdf |
16th Mar 2017, 9:04 pm | #6 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
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Re: Huge NPN transistor
still a current product, no pun intended. I've just replaced one in an emergency shutdown circuit of a laser cutter. Switching of rated current via a simple control voltage and a few micro amps.
Big IGBTs and their darlington equivalent aren't readily supplanted by mosfets. They arent robust enough for the type of application these IGBTs are used for, eg motor control, charging, inverters, traction and power conversion. For equipment typically on 415V, you ideally need 1600V rated devices, not easily (or cheaply) found at these currents with mosfets. These contain beryllium oxide BTW, not to be cut open or drilled.
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Kevin Last edited by McMurdo; 16th Mar 2017 at 9:17 pm. |
16th Mar 2017, 10:03 pm | #7 |
Octode
Join Date: Jul 2009
Location: Cheshire, UK.
Posts: 1,706
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Re: Huge NPN transistor
Those in the picture are probably what was on the floor next to an industrial compressor being repaired at work, presumably for controlling the drive motor.
I also used to change loads of the ordinary darlington version of these on DC to DC converter units, I think they were 1200v rated but at a lower current. They did manage to open themselves sometimes, usually just the sides blew out, but occasionally they went bang with enough force to bend all the copper bars above. The sticky insulating snot inside was always difficult to remove from the surrounding parts. David |
16th Mar 2017, 10:59 pm | #8 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
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Re: Huge NPN transistor
Modern compressors invariably use IGBTs for either a variable frequency inverter or more these days to generate the waveforms for the new switched reluctance motors. Those big IGBTs are then usually bolted straight into the case of the compressor.
Last year I went to diagnose a fault on a 400kW compressor (blown IGBTs) and after I went someone tried to switch it on and run it. The remaining good IGBTs tried to leap out of the side of the compressor, frightening the guy standing next to them somewhat. An former aquaintance of mine used to work at the local (demolished) GEC inverter factory where they told people IGBT stood for 'It Goes Bang Today'. Bit of stoke humour.
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Kevin |
17th Mar 2017, 12:12 am | #9 |
Dekatron
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
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Re: Huge NPN transistor
I wouldn't want to be there if that blew. I blew up an IRF510 a year trying to build a switching inverter and that went with quite a bang!
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17th Mar 2017, 12:35 am | #10 | |
Dekatron
Join Date: Nov 2010
Location: Oxford, UK.
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Re: Huge NPN transistor
Quote:
For example a SiC MOSFET with 1200V, 65A, 59m-ohm Rds(on) http://www.st.com/content/st_com/en/...twa50n120.html And even more outrageous devices are on their way, like 650V, 100A and 22m-ohm again all at 200C junction. |
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17th Mar 2017, 6:38 am | #11 |
Dekatron
Join Date: Jul 2009
Location: Sleaford, Lincs. UK.
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Re: Huge NPN transistor
Nice devices Andy and worth a few bob too.
I don't understand how those little leads on Mosfet's are supposed to conduct 100A, even if it's transient or pulsed. the contact wires on the die are even thinner, so how. Andy's IGBT looks much tougher. Andy.
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17th Mar 2017, 5:02 pm | #12 | |
Heptode
Join Date: Mar 2017
Location: Cedar Grove, Wisconsin, USA.
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Re: Huge NPN transistor
Quote:
I drive a Hybrid car as a daily driver, a Prius. Invertor drive, 200 volts DC in, 500 volts, 3 phase AC out @ 62KW. Water cooled. Wondering what kind of devices, it uses. I have to look up the theory of operation again. |
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17th Mar 2017, 5:07 pm | #13 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
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Re: Huge NPN transistor
The 300A devices on the laser cutters are mounted on a water cooled heatsink. It isn't all about current, it's about dissipation. A transistor that switches at 18kHz will dissipate heat each time it transitions from off to on and vice versa. Getting rid of that heat before the SOA is exceeded takes some doing.
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Kevin |
17th Mar 2017, 10:10 pm | #14 |
Heptode
Join Date: Dec 2003
Location: South Yorkshire, UK.
Posts: 900
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Re: Huge NPN transistor
Hi Kevin
What is the foil warning label on your picture. Anti static ?
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17th Mar 2017, 11:15 pm | #15 |
Dekatron
Join Date: Jun 2009
Location: Staffordshire Moorlands, UK.
Posts: 5,263
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Re: Huge NPN transistor
yes a foil shorting link is in place until just before installation. There is a seperate light duty emitter terminal alongside the gate for the twisted pair signal cable, these two are joined.
Smaller IGBT modules have faston gate/emitter terminals and usually come with conductive foam pushed over them.
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Kevin |
18th Mar 2017, 2:09 am | #16 |
Octode
Join Date: Nov 2013
Location: Penrith, Cumbria, UK
Posts: 1,993
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Re: Huge NPN transistor
this stuff is interesting!
i was just kind of gobsmacked to see a vintage device so big, len's been retired 20 years so it wasn't a modern bit of kit. |