X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 05 Jul 2006 00:30:12 -0400 Message-ID: X-Original-Return-Path: Received: from smtp102.sbc.mail.mud.yahoo.com ([68.142.198.201] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with SMTP id 1223528 for lml@lancaironline.net; Tue, 04 Jul 2006 13:07:23 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.198.201; envelope-from=elippse@sbcglobal.net Received: (qmail 90446 invoked from network); 4 Jul 2006 17:06:39 -0000 Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@75.15.132.244 with login) by smtp102.sbc.mail.mud.yahoo.com with SMTP; 4 Jul 2006 17:06:39 -0000 X-Original-Message-ID: <000b01c69f8c$3e15ed20$f4840f4b@Computerroom> From: "Paul Lipps" X-Original-To: "Marv Kaye" Subject: Visibility, transient voltage X-Original-Date: Tue, 4 Jul 2006 10:06:49 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0008_01C69F51.9072D550" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 This is a multi-part message in MIME format. ------=_NextPart_000_0008_01C69F51.9072D550 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable One thing that may enhance your visibility are alternately-flashing = lights. Check the EAA 170 site for the magazine article to make an = inexpensive flasher.=20 Tom- the kind of transient I was referring to for the battery is that = which would stem from closing-through the alternator circuit breaker = with the alternator putting out over 100V. A switch closure will usually = yield rise-times in the sub-microsecond region, limited only by = inductance and capacitance. BTW, were you aware that the capacitor = across the points of an ignition system is not to protect the points, = per se. Its main function is to slow down the rate-of-rise of the = fly-back voltage across the opening points so that it is always below = the dielectric breakdown-voltage in the space between the points. = Otherwise, there will be an arc across the points maintaining current = flow through the coil which kills its fly-back voltage generation, = giving a very, very small spark voltage. Scott-I looked at the BB schematic of the OV circuit; it has a = time-constant of about 27 milliseconds, which, electrically-speaking, is = a long time! It also matters how close you mount this circuit to your CB = and regulator, since wiring has inductance and capacitance which further = slows things down. When you bench adjust this circuit, you do it for = steady-state, not transient conditions. Garey-very interesting scenario; another one is worn slip-ring brushes = in the alternator making intermittent contact as in the LML posting that = started all this conjecture. I'm not sure what is meant by the = alternator being a "current-limited" device; is that due to some = internal circuitry or just the stator winding resistance? If the latter, = then what you are saying is that with maximum field current at high rpm, = there is all but 14V of its output being dropped across the internal = resistance, or 125V-14V. Is that the case? The open battery condition = you postulate is a real zinger! 'looks like that could let the smoke out = of a lot of electronic equipment! ------=_NextPart_000_0008_01C69F51.9072D550 Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable
One thing that may enhance your visibility are=20 alternately-flashing lights. Check the EAA 170 site for the magazine = article to=20 make an inexpensive flasher.
 
Tom- the kind of transient I was referring to = for the=20 battery is that which would stem from closing-through the alternator = circuit=20 breaker with the alternator putting out over 100V. A switch closure will = usually yield rise-times in the sub-microsecond region, limited = only by=20 inductance and capacitance. BTW, were you aware that the capacitor = across the=20 points of an ignition system is not to protect the points, per se. Its = main=20 function is to slow down the rate-of-rise of the fly-back voltage = across=20 the opening points so that it is always below the dielectric = breakdown-voltage=20 in the space between the points. Otherwise, there will be an arc across = the=20 points maintaining current flow through the coil which kills its = fly-back=20 voltage generation, giving a very, very small spark = voltage.
 
Scott-I looked at the BB schematic of the OV = circuit; it=20 has a time-constant of about 27 milliseconds, which, = electrically-speaking, is a=20 long time! It also matters how close you mount this circuit to your CB = and=20 regulator, since wiring has inductance and capacitance which further = slows=20 things down. When you bench adjust this circuit, you do it for = steady-state, not=20 transient conditions.
 
Garey-very interesting scenario; another one is = worn=20 slip-ring brushes in the alternator making intermittent contact as in = the LML=20 posting that started all this conjecture. I'm not sure what is meant by = the=20 alternator being a "current-limited" device; is that due to some = internal=20 circuitry or just the stator winding resistance? If the latter, then = what you=20 are saying is that with maximum field current at high rpm, there is all = but 14V=20 of its output being dropped across the internal resistance, or = 125V-14V. Is=20 that the case? The open battery condition you postulate is a real = zinger! 'looks=20 like that could let the smoke out of a lot of electronic=20 equipment! 
------=_NextPart_000_0008_01C69F51.9072D550--