Me, closure? I honestly don’t think I am a good person to ask about just that. And I haven’t gotten to mounting a PSU yet to test temps and so. And maths I have not done for these yet…
But.
The IRFP150s can take more beating than 240s. Infineons specced at maks 160 watts I think, versus a bit lower for 240s. Vishay 150s can take 230 watts or so, if I remember datasheet correctly.
5U sinks, IME, are very happy @ 90-95 degrees dissipation, cruising, but can take 115 watts per sink with more dcices without imminent explosion.
But for TO3P package, Mighty sez never to cross 50 watts per device. To be safe with my sinks, maybe 45 watts is max, but maybe 50 too.
So plan is to start at 35 watts, and work my way up.
Meaning starting at approx 1A5, working towards 2, not exceeding 2A2, with 22V5 rails under load.
Plan is to measure temps and so on, ensuring all is good, before increasing. Wanna skip babysitter, probably ending up at 40-45 or so per device.
Took care with torque wrench during mosfet assembly, @ 0N85.
Regards,
Andy
But.
The IRFP150s can take more beating than 240s. Infineons specced at maks 160 watts I think, versus a bit lower for 240s. Vishay 150s can take 230 watts or so, if I remember datasheet correctly.
5U sinks, IME, are very happy @ 90-95 degrees dissipation, cruising, but can take 115 watts per sink with more dcices without imminent explosion.
But for TO3P package, Mighty sez never to cross 50 watts per device. To be safe with my sinks, maybe 45 watts is max, but maybe 50 too.
So plan is to start at 35 watts, and work my way up.
Meaning starting at approx 1A5, working towards 2, not exceeding 2A2, with 22V5 rails under load.
Plan is to measure temps and so on, ensuring all is good, before increasing. Wanna skip babysitter, probably ending up at 40-45 or so per device.
Took care with torque wrench during mosfet assembly, @ 0N85.
Regards,
Andy
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Baaaah. You said in a post earlier, 0N9, maybe even 0N85. So I did that. I can prolly retighten a wee bit more without danger 
Wrt math not done yet, I was talking about max case temp and max junction temp. Then again, if Mighty sez 50 watts is «ok»/his absolute max, that kinda sets my upper limit anyways. But nice to know what lines not to cross during biasing, so I’ll read up anyways.
Wrt math not done yet, I was talking about max case temp and max junction temp. Then again, if Mighty sez 50 watts is «ok»/his absolute max, that kinda sets my upper limit anyways. But nice to know what lines not to cross during biasing, so I’ll read up anyways.
Thanks for showing interest, btw. I’ll do my best to keep you and others informed of the progress. The plan was taking lots of pictures along the way, for example of the needle pins and soldering of them, which turned out pretty neat but is completely disguised by heatshrink. Just have so little time that I really need to keep going as fast as possible once I have a few minutes here and there.
Regards,
Andy
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Well after a very sluggish start, I FINALLY soldered my first components onto my power supply PCB. I have what (IN THEORY...) should be my last Mouser order in the way.
For some reason, I was having some 'issue' soldering the 3W resistors on the board. 700 degrees on the soldering iron, nice Kester lead solder. I got beautiful, good solder connections on the rear of the board, but I did not see any solder flow through to the other side. It did this when I soldered the 3W resistors on my ACA (it happened naturally and easily) - but not on this. No issue on the smaller parts (the solder flowed to the other side of the PCB). My fix was to hit the other side of the board with more solder...to ideally fill the holes in the PCB.
I felt like I was leaving the tip on unnaturally long (longer than I have on any PCB), so I didn't want to push my luck. Can anyone else comment on their experience?
For some reason, I was having some 'issue' soldering the 3W resistors on the board. 700 degrees on the soldering iron, nice Kester lead solder. I got beautiful, good solder connections on the rear of the board, but I did not see any solder flow through to the other side. It did this when I soldered the 3W resistors on my ACA (it happened naturally and easily) - but not on this. No issue on the smaller parts (the solder flowed to the other side of the PCB). My fix was to hit the other side of the board with more solder...to ideally fill the holes in the PCB.
I felt like I was leaving the tip on unnaturally long (longer than I have on any PCB), so I didn't want to push my luck. Can anyone else comment on their experience?
By the way the tool I wrote about ~64 pages earlier.
It have 0.05 Nm steps like 0.85 Nm, 0.9 Nm, 0.95 Nm and so on.
Bits fixation is so neat and all mechanisms work so smooth.
The feel in the hand is so pleasant. Not cheap not luxury, just right.
Another tool I also bought is Knipex cable cutter.
Unnecessary. But there was a good discount so I could not resist..
It cuts the cable like a butter.
This tool is also meant to cut only copper or aluminum conductors.
Steel will damage cutting edges.
Amazing feel just to hold it in my hand. So smooooooth.
Both
Attachments
LOL, yes thats true! No open flames nor smoke yet though
In fact im having trouble getting the mosfets hot enough. Im using the 4U deluxe chassis, a 400VA transformer with 20V secondaries. With a bias of 400mV the mosfets get to around 53 degrees C and the heatsinks around 48. It seems as a small difference? Despite that, I thought 400mV should be the limit in that chassie? I guess Ill need to crank it up to find the bias/ temperature limit.
In fact im having trouble getting the mosfets hot enough. Im using the 4U deluxe chassis, a 400VA transformer with 20V secondaries. With a bias of 400mV the mosfets get to around 53 degrees C and the heatsinks around 48. It seems as a small difference? Despite that, I thought 400mV should be the limit in that chassie? I guess Ill need to crank it up to find the bias/ temperature limit.
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