Was at the scrap metal yard the other day. While salvaging 30kg of heatsinks I came across this IRF transistor.
HOW suitable is this transistor for say SoZ or the Zen v4 - anotherwords, how comparable is it to the IRF240? I recall IRF made some mosfets (ie IRF140?) that gave better performance than the 240.
from: http://www.microsemi.com/catalog/part.asp?id=46162
Breakdown Voltage Drain-to-Source BVDSS 200 V
Drain Current (Continuous) ID 25 A
Power Dissipation PD 150 W
Thermal Resistance, Junction to Case RqJC 0.83 ºC/Watt
BQ
HOW suitable is this transistor for say SoZ or the Zen v4 - anotherwords, how comparable is it to the IRF240? I recall IRF made some mosfets (ie IRF140?) that gave better performance than the 240.
from: http://www.microsemi.com/catalog/part.asp?id=46162
Breakdown Voltage Drain-to-Source BVDSS 200 V
Drain Current (Continuous) ID 25 A
Power Dissipation PD 150 W
Thermal Resistance, Junction to Case RqJC 0.83 ºC/Watt
BQ
Attachments
I would think it would work unless there is too much capacitance involved with this device.....are there alot of them?
Mark
Mark
Mark,
There wasn't many ; only 8 that were individually mounted on the heatsinks that I was after. Interestingly, they were on a single PCB so possibly all 8 of them may be matched.
Quite often I come across similar transistors and large can computer grade capacitors at this yard. As long as i'm buying those heavy heatsinks, they don't bother charging anything for the non-metal related items. Big can electrolytics do age but I havn't heard of transistors losing their potency with age?
Nevertheless, most transistors are cheap - it's just the exotic older ones that are no longer in production I wouldn't mind trying.
BQ
PS: may be a silly question but has anyone proven that TO-3 type transistors sound better than TO-247 ones of the same spec?
There wasn't many ; only 8 that were individually mounted on the heatsinks that I was after. Interestingly, they were on a single PCB so possibly all 8 of them may be matched.
Quite often I come across similar transistors and large can computer grade capacitors at this yard. As long as i'm buying those heavy heatsinks, they don't bother charging anything for the non-metal related items. Big can electrolytics do age but I havn't heard of transistors losing their potency with age?
Nevertheless, most transistors are cheap - it's just the exotic older ones that are no longer in production I wouldn't mind trying.
BQ
PS: may be a silly question but has anyone proven that TO-3 type transistors sound better than TO-247 ones of the same spec?
Don't know...you would have to ask the Man Himself about the sound difference between the two. The metal casings do not suffer nearly as badly from thermal fatigue over repeated thermal cyclings though. I know that plastics have gotten better in that department, but I doubt they can match metal case semi's.
Its too bad there were not more of them but you never know....more may turn up in the near future if more equipment like that is disposed of. Sounds like a handy yard to have around!
Mark
Its too bad there were not more of them but you never know....more may turn up in the near future if more equipment like that is disposed of. Sounds like a handy yard to have around!
Mark
Almost TWICE the Ciss = 3000pF
Perfect for Pass Amplifier DIY-selvers
MOSPEC SEMICONDUCTOR [url]www.mospec.com[/URL]
Put In Favourites !!!!!!!!!!!!
----------------------------------------------------
http://www.mospec.com.tw/mosfet.htm
IRF240 200V 18A 0.18ohm 1600pF 125W TO-3
IRF252 200V 25A 0.12ohm 3000pF 150W TO-3
-----------------------------------------------------
You can use this transistor
But you might have to use MORE current in the Driverstage (double the current)
to compensate for the higher Capacitance 3000/1600
You have to consult Nelson. There might be enough current already.
Nelson likes to be on The Safe Side (regarding currents!!!)
----------------------------------------------------------------
/halo - ask a question - halo can do the SEARCH
Found this NICE SITEMark A. Gulbrandsen said:
Perfect for Pass Amplifier DIY-selvers
MOSPEC SEMICONDUCTOR [url]www.mospec.com[/URL]
Put In Favourites !!!!!!!!!!!!
----------------------------------------------------
http://www.mospec.com.tw/mosfet.htm
IRF240 200V 18A 0.18ohm 1600pF 125W TO-3
IRF252 200V 25A 0.12ohm 3000pF 150W TO-3
-----------------------------------------------------
You can use this transistor
But you might have to use MORE current in the Driverstage (double the current)
to compensate for the higher Capacitance 3000/1600
You have to consult Nelson. There might be enough current already.
Nelson likes to be on The Safe Side (regarding currents!!!)
----------------------------------------------------------------
/halo - ask a question - halo can do the SEARCH
Paralleling of Power MOSFETs for Higher Power Output
I found this page with Technical Papers at - www.irf.com
this page have about MOSFETs including HEXFETs
http://www.irf.com/technical-info/papers.html#mosfet
--------------------------------------------------------
Interesting for All of You who PARALLELL mosfets
this will include a great number of you Pass-amp-Builders
This PDF is 30 pages and deals with
Paralleling of Power MOSFETs for Higher Power Output
James B. Forsythe, Member IEEE
International Rectifier, E1 Segundo, California
Abstract - Dynamic current and transition energy unbalance resulting from parameter mismatch between
parallel MOSFET branches are mapped over wide operating ranges. Unbalance generator magnitudes are given
for HEXFET Power MOSFET data sheet ant typical production batch extremes.
-----------------------
I (c) Potential Causes of Unbalance
There are several conceivable causes for current unbalance that may result in a particular device exceeding its peak current or
continuous thermal ratings. Unbalance may be generated by:
(i) device parameter mismatch
- ON resistance mismatch RDS (on)
- threshold voltage (VT)
- gain factor (GF, µ g fs )
- capacitance mismatch (CGD, gate-to-drain (Miller) or CGS, gate-to-source)
(ii) gate driver mismatch
- decoupling resistor (RG)
- gate loop inductance (LG)
(iii) power circuit mismatch
- branch inductance (LD, excluding LS)
- source inductance common to power and gate circuit (LS)
Paralleling of Power MOSFETs for Higher Power Output PDF
Nota bene: Even Nelson could learn a few small things by reading this PDF
Or maybe he has learned all there is?? If he thinks so, he is to pity ..... 😉 😕 😉
---------------------------------------------------------------
halo - got no illusions about any person - and still is in lack of a GURU - besides his ALLMIGHTY GOD
- do as halojoy does: .... BE YOUR OWN GURU ....
I found this page with Technical Papers at - www.irf.com
this page have about MOSFETs including HEXFETs
http://www.irf.com/technical-info/papers.html#mosfet
--------------------------------------------------------
Interesting for All of You who PARALLELL mosfets
this will include a great number of you Pass-amp-Builders
This PDF is 30 pages and deals with
Paralleling of Power MOSFETs for Higher Power Output
James B. Forsythe, Member IEEE
International Rectifier, E1 Segundo, California
Abstract - Dynamic current and transition energy unbalance resulting from parameter mismatch between
parallel MOSFET branches are mapped over wide operating ranges. Unbalance generator magnitudes are given
for HEXFET Power MOSFET data sheet ant typical production batch extremes.
-----------------------
I (c) Potential Causes of Unbalance
There are several conceivable causes for current unbalance that may result in a particular device exceeding its peak current or
continuous thermal ratings. Unbalance may be generated by:
(i) device parameter mismatch
- ON resistance mismatch RDS (on)
- threshold voltage (VT)
- gain factor (GF, µ g fs )
- capacitance mismatch (CGD, gate-to-drain (Miller) or CGS, gate-to-source)
(ii) gate driver mismatch
- decoupling resistor (RG)
- gate loop inductance (LG)
(iii) power circuit mismatch
- branch inductance (LD, excluding LS)
- source inductance common to power and gate circuit (LS)
Paralleling of Power MOSFETs for Higher Power Output PDF
Nota bene: Even Nelson could learn a few small things by reading this PDF
Or maybe he has learned all there is?? If he thinks so, he is to pity ..... 😉 😕 😉
---------------------------------------------------------------
halo - got no illusions about any person - and still is in lack of a GURU - besides his ALLMIGHTY GOD
- do as halojoy does: .... BE YOUR OWN GURU ....
halojoy,
Nelson has stated on more than one occassion that Vgs matching has a large effect and is a very easy test to do. If you use devices from the same lot code, that is they are all from the same wafer, you usually find that the devices that were physically near each other on the wafer have the closest match for Vgs and also generally have a tight tolerance in all the other relevant specs.
As for the original question, it would help if we knew the transconductance of this device.
Nelson has stated on more than one occassion that Vgs matching has a large effect and is a very easy test to do. If you use devices from the same lot code, that is they are all from the same wafer, you usually find that the devices that were physically near each other on the wafer have the closest match for Vgs and also generally have a tight tolerance in all the other relevant specs.
As for the original question, it would help if we knew the transconductance of this device.
I found that to be very true. I ordered 100 IRFP240's from the same lot code and they are all pretty close to each other. Needless to say all 100 devices can find their way into amplifiers!!
Mark
Mark
How good
BQ,
In my experience TO-3s can produce a mechanical sound when driven hard, the metal cap will be vibrating. Plastic TO-247s have more internal damping it seems, although they also can "sing" when too loose (correct Frank?) on the heatsink.
Jan Didden
Super_BQ said:
BQ,
In my experience TO-3s can produce a mechanical sound when driven hard, the metal cap will be vibrating. Plastic TO-247s have more internal damping it seems, although they also can "sing" when too loose (correct Frank?) on the heatsink.
Jan Didden
Nelson Pass said:I say use them and be happy.
Nelson,
It's interesting to note that of all the people on the board, you seem the least worried about many of the "possible" detrimental effects of parts on the quality of sound.
Is this because you've learned that in many cases it won't matter, or is it because you've grown tired of endless speculation?
I know how I feel, and am curious what your feelings are. I would hope for maybe a quick paragraph on the subject.
BQ,
As for the transistors, I would think that having them Pre-Mounted would make building prototypes easy!
-Dan
Too many would-be DIYers sit on the sidelines wondering
about the details and afraid to try.
A nice dumb amp like a Zen will work with just about anything,
and once you get going, you can worry about the subtle
differences between this device and that.
Like sex, DIY is special the first time.
And the second.
And the third.
And the fourth.
And the fifth.
And the sixth.
And the seventh.
And the eighth.
And the ninth.
And the tenth.
And so on..........
🙂
about the details and afraid to try.
A nice dumb amp like a Zen will work with just about anything,
and once you get going, you can worry about the subtle
differences between this device and that.
Like sex, DIY is special the first time.
And the second.
And the third.
And the fourth.
And the fifth.
And the sixth.
And the seventh.
And the eighth.
And the ninth.
And the tenth.
And so on..........
🙂
Nelson Pass said:
Interesting.
Myself, I feel that there will be differences in any part you use, but often enough of these differences will be small. (That is, if you're comparing somewhat similar parts). Assuming the design is good, many of these differences should not be detectable.
As for your analogy... ...what can I say. When you're right, you're right!
Re: How good
I too have heard TO-3's "sing" at 2-3 kHz when driving a dummy load and fed by an oscillator. You can hear it from about a metre away in quiet surroundings.janneman said:
One of the older towed torpedo decoys the Navy employed used three large TO3 based amps that used to "sing". The sound the amp emitted was much like the swept freq signal the towed body was emitting and around 60dB. Very noticable even in a noisy equipment room.
Since on the subject of transistors I have this question, for an aleph 2 which is better and why: IRFP244 or IRFP240? ( I have written in my notes that per Nelson Pass the IRFP240 is better, but I didn't record where I found that comment) Thanks Mike Z
IRFP244 & IRFP240
http://users.bigpond.net.au/mefinnis/passlabs/aleph4.htm
They have most data almost the same.
But RDSon is lower for IRFP240 0.18 vs. 0.28 ohm
Ciss, capacitance is 1275 for IRFP240, vs 1400pF for IRFP244
that is no significant difference
Read more in PDF Datasheets.
On this page you can download most IRFPxxx
PDF Datasheets:
http://kyungsung-elect.co.kr/irf-switch.htm
-------------------------------------------------
Teach yourself to Understand those data
and you will be able find out more by YOURSELF.
/halojoy - trusts more in his own judgement -
if he would start put his trust in other's opinions,
he would have to change his mind 10 times a day,
at least once by every answer posted 😀 😀
www.geocities.com/halomatics
Here is a guy using IRFP244 in an Aleph:MikeZ said:
http://users.bigpond.net.au/mefinnis/passlabs/aleph4.htm
They have most data almost the same.
But RDSon is lower for IRFP240 0.18 vs. 0.28 ohm
Ciss, capacitance is 1275 for IRFP240, vs 1400pF for IRFP244
that is no significant difference
Read more in PDF Datasheets.
On this page you can download most IRFPxxx
PDF Datasheets:
http://kyungsung-elect.co.kr/irf-switch.htm
-------------------------------------------------
Teach yourself to Understand those data
and you will be able find out more by YOURSELF.
/halojoy - trusts more in his own judgement -
if he would start put his trust in other's opinions,
he would have to change his mind 10 times a day,
at least once by every answer posted 😀 😀
www.geocities.com/halomatics
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