Date: Mon, 20 Dec 1999 13:34:50 -0700 From: Warner Losh <imp@village.org> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: Wes Peters <wes@softweyr.com>, freebsd-hackers@FreeBSD.ORG Subject: Re: Cool little 100BaseTX switch - they're coming down in price Message-ID: <199912202034.NAA18342@harmony.village.org> In-Reply-To: Your message of "Mon, 20 Dec 1999 12:24:30 PST." <199912202024.MAA17008@apollo.backplane.com> References: <199912202024.MAA17008@apollo.backplane.com> <199912190410.UAA01049@apollo.backplane.com> <385C60FC.7613CB55@bellatlantic.net> <19991218225758.A23729@futuresouth.com> <199912190556.AAA08484@whizzo.transsys.com> <199912191943.LAA06826@apollo.backplane.com> <385D47D3.FCEE9EAB@softweyr.com> <199912192127.NAA09156@apollo.backplane.com> <385DDE7A.1A0ED466@softweyr.com> <199912201949.LAA16719@apollo.backplane.com>
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In message <199912202024.MAA17008@apollo.backplane.com> Matthew Dillon writes: : : or higher, which makes things a whole lot easier. No 60Hz humm, no : : vibration - hell, you can even run the frequency up past 100 MHz and : ^^^^ : Needless to say I meant 100 KHz here, not 100 MHz. Yes. The nice thing about modern swithcing power supplies are that if you DO hear any vibration, you know you have big problems and are courting disaster. At least that's my experience in homebrewing a 12V -> 16V converter for my Sony VAIO 505TS. The original magnetics I chose easily overloaded, producing a noticable hum. I didn't think much of this at the time, but about 3 hours into my test the coil started smoking a little, and then the cascade failure from that caused an overload on the regulator ic I was using and after the pop no more hum, but no more +16V either :-( And I was only running at 20 kHz.... Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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