Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757810AbXFMJfF (ORCPT ); Wed, 13 Jun 2007 05:35:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756637AbXFMJe4 (ORCPT ); Wed, 13 Jun 2007 05:34:56 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:33585 "HELO embla.aitel.hist.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755082AbXFMJez (ORCPT ); Wed, 13 Jun 2007 05:34:55 -0400 Message-ID: <466FB758.1020104@aitel.hist.no> Date: Wed, 13 Jun 2007 11:22:32 +0200 From: Helge Hafting User-Agent: Icedove 1.5.0.10 (X11/20070329) MIME-Version: 1.0 To: Jan Engelhardt CC: David Schwartz , "Linux-Kernel@Vger. Kernel. Org" Subject: Re: PC speaker References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1210 Lines: 30 Jan Engelhardt wrote: > Since you can set the x86's crystals frequency from 1193182 to 18 Hz > (PIT_TICK_RATE / 1 to PIT_TICK_RATE / 65535) [*], you can never really > bust it. But even then, what would a speaker do it was constanly given > +5V? (I _suppose_ the other level is 0V, not -5V -- makes for easy > design.) That's IMO just like a sound file with volume(x) = 1, nothing > spectacular if you ask me. > I guess a motherboard don't provide enough current to burn out that speaker. But generally, speakers that handle some maximum alternating current *will* burn out if you give them the same amount DC. This becasue speakers are designed to handle AC - some of the energy is dissipated as sound waves, some as an alternating magnetic field, some has heat. And the speaker moves, so moving air helps cooling it. A speaker getting DC converts all that current into heat only, and it stands still so no extra cooling. So it burns out. Helge Hafting - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/