Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!van-bc!ubc-cs!alberta!herald.usask.ca!ccu.umanitoba.ca!bison!sys6626!inqmind!jon From: jon@inqmind.bison.mb.ca (Jon Chesnut) Newsgroups: sci.electronics Subject: Re: Fan for my amp revisited Message-ID: Date: Thu, 18 Apr 91 11:39:59 CDT References: <1991Apr17.022927.7094@msb.com> Organization: The Inquiring Mind 1 204 488-1607 ritz@msb.com (Chris Mauritz) writes: > Someone was kind enough to send me a message saying that controlling > the speed of an AC fan was not as simple as adding a pot. OK, > how about I use a DC fan and siphon off power from the power supply > for the amp? The power supply seems to be hefty. Would there > be any danger that a small DC muffin fan would draw enough current > to affect the amplifier in any negative way? > Before you go any further, I'm concerned (slightly) about adding a fan. Solid State amps run better warm..... why did you want to add the fan in the first place? Rather than adding a DC fan, why not attach a thermostat to the heat sink. YAMAHA standard says 50 degrees celcius (sorry, I'm lousy in Imperial measures!) Is the ideal, so their thermostats are set for cut IN at 60 degrees, and OUT at 45 degrees. If this is a ROCK 'N ROLL type amp, such a circuit would be great, and much simpler to do, and probably better for the amp than tapping off it's supply. If it's a home amp, the cut-ins and cut-outs would probably get annoying... AARGGHH.... I can't find a farenheit conversion table around ANYWHERE! Later, Jon Chesnut