0-50V 0-10A Variable SMPS

SunnySkyguy said:

Why drop 24V to 5V for 5V fan.

• Select a 24Vdc fan.
• Delete 5V linear Reg as it will waste almost 4x power as the fan.
• https://www.bing.com/images/search?q=24VDC+Cooling+Fans&FORM=IRBPRS&=0
• Use Nch-FET with Thermistor bias on hot spot.set to 50'C over 5'C range. with low side regulation.
• 2 fans are more reliable than 1.
• Use PC-film plenum to control air flow over hot spots for low RPM but max linear surface speed over hotspot.

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SunnySkyguy said:

Still wiser to regulate fan with a thermistor and low overhead air flow plenum.

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SunnySkyguy said:

Still wiser to regulate fan with a thermistor and low overhead air flow plenum.

Often, the Core is hotspot, ... epoxy thermistor to core then with twisted pair to board header, etc or hardwire for rugged applications.

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treez said:

I would use a micrel integrated chip boost converter (or sepic etc) to provide the startup voltage to your chip.....then it can disable itself, or you just leave it in there. I think its MICXXXX or MIC33XX or something....good and few components, as the fet is in the control chip,
that is your voltage is not quite right, as u described, so use the micrel to get it to what you want.

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