I was also looking at those ARCTIC fans on amazon. Not a bad deal. Let us know how they work if/when you get them. I'm thinking about starting an ALPHA 4R build soon and using these fans with some more of the HP DL580 G7 heatsinks. I have all the parts, just need the time, as usual. Has anyone else actually built the ALPHA 4R yet?
The meanwell smps I got for another project has an auxiliary fan connection. Have you ever used that or know if it is filtered somehow? I might need a fan in that build. It’s an ACA using the Dell Xeon heatsink, I will use the same heatsink for both channels and believe it won’t need a fan, but as a plan b I found pretty useful that the psu has a fan connector (up to 0.5A 12v)
And answering to myself, no
too high voltage for regular step downs. Maybe I just add small smps just for fans.Rails seems to be +/-39.7vdc under load, and mosfet L-clamps feels quite cool now really, must be under 40c easily. Don't have that thermometer though.. I did some modifications for clamping and added thick copper bars on top of mosfets, then L-clamps to make tight package. And goop, goop everywhere. Heatsinks/pipes gets quite warm now, seems that heat is transferring quickly.
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And answering to myself, no
Rails seems to be +/-39.7vdc under load, and mosfet L-clamps feels quite cool now really, must be under 40c easily. Don't have that thermometer though.. I did some modifications for clamping and added thick copper bars on top of mosfets, then L-clamps to make tight package. And goop, goop everywhere. Heatsinks/pipes gets quite warm now, seems that heat is transferring quickly.
I would use a mall tranny to power those cooling fans. For two reason to avoid any noise etc pickup, second, if something goes wrong your fans still remain on power for cooling in case the amp fuse go off etc, just connect that transformer directly where your AC comes in.
Just add a small 12v class 2 wall transformer (inside your case) connected to the mains. Put a small CLC between the 12v trafo (about 800mA should be more than enough as that is what I am running four fans with). It's good to have the fans on a separate circuit though to reduce noise injection into your audio path (which is dead silent at present).
Alternatively, an LM317HV can drop up to 50v down to 12v. Give it a good heatsink. Alternatively, a string of 1N4004's in series is good for 0.6v ea so qnty 10 is 6v drop to 29v, then use a 7812 now that it is under 35v.
Alternatively, an LM317HV can drop up to 50v down to 12v. Give it a good heatsink. Alternatively, a string of 1N4004's in series is good for 0.6v ea so qnty 10 is 6v drop to 29v, then use a 7812 now that it is under 35v.
Try adding CLC from Aksa Lender Preamp in between the fan and SMPS. If you used a Class 2 linear 12v Wall transformer you can be sure noise is from fan and not smps. You may need a CMC between your mains and your SMPS. That’s why I like linear power to drive my PWM.
BPD2EE Hammond Manufacturing | Mouser
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Just tested these fans. They are not as quiet as the 120mm Deep Cool - the fans still seem to spin quite fast at the lowest speed setting and have plenty of torque. I can’t stall it - after stopping it with my finger, it spins right back up. It’s a great deal for $20 though at $4 a fan.
noctua flx
NF-A12x25 FLX seems high-end fans in that size.
Noctua NF-A12 and P12 Redux Fan Group Test Review - Airflow performance
and the next page .
Something simililar vs performace / acustic level with in the 180mm-200mm would be nice . Not much to complain of the old phobia g-silent 700rpm but still.
Got a spare 4 of noiseblocker silent. Very light breeze.
NF-A12x25 FLX seems high-end fans in that size.
Noctua NF-A12 and P12 Redux Fan Group Test Review - Airflow performance
and the next page .
Something simililar vs performace / acustic level with in the 180mm-200mm would be nice . Not much to complain of the old phobia g-silent 700rpm but still.
Got a spare 4 of noiseblocker silent. Very light breeze.
Simple solution: just added a 27ohm 1w resistor on 12v line from PSU to PWM control module. That drops voltage to 8.6v and control electronics and beeper etc all work but fan is now naudible. Still cools my my Alpha 20 just fine. I manually stalled it with my finger and it beeps. I let go and it spins up again just fine.
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Thanks for the info on those fans X. I think I'll be buying a few pretty soon.
You could add a ntc in suitable location, connect a ntc to a comparator whose output swings high if the ntc is smaller than the sum of pot. and fixed resistor. Alarm adjusted by Pot.
A buzzer was used bc847b tlc271cd smd a few components in the 90's for pc over temp alarm.
Or use a 317 regulator with thermistor.
Or 2 to92 Bc547b bjt's one to126 bd140 few resistors kty10 for a fan regulator
Then again ds1620 & a at89c1051 you could record a storage temp values, easier nowdays so many independent platforms.
But these are easy and you can find ready made units cheap soldered ready made. Or your old pc interface for fan controller with graphics setting curves for fans as pc with finer bioses does nowdays if the knob or automated function is not for personal liking.
A buzzer was used bc847b tlc271cd smd a few components in the 90's for pc over temp alarm.
Or use a 317 regulator with thermistor.
Or 2 to92 Bc547b bjt's one to126 bd140 few resistors kty10 for a fan regulator
Then again ds1620 & a at89c1051 you could record a storage temp values, easier nowdays so many independent platforms.
But these are easy and you can find ready made units cheap soldered ready made. Or your old pc interface for fan controller with graphics setting curves for fans as pc with finer bioses does nowdays if the knob or automated function is not for personal liking.
Can't compete with the chinase. I actually measured a aliexpress diy amp, was amazed of quality of most components. I can't speak of longevity. A good diy amp should last 20years. Even the cheap japanese home theater amps usully lasts even over 20 years without fault. To the time there's some semis not manufactured anymore for service repair diy at least.
Even if powered up most of time no fault.
Everyone knows heat is probably the main concern in electronics for longevity.
So keep cool. Keep the dust out of enclosure by filter and do regular cleaning.
Even if powered up most of time no fault.
Everyone knows heat is probably the main concern in electronics for longevity.
So keep cool. Keep the dust out of enclosure by filter and do regular cleaning.