---------------------------------------------------------- CorvairEngines-List Digest Archive --- Total Messages Posted Fri 10/16/15: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:01 AM - Re: tachometer (D L Josephson) 2. 12:34 PM - Re: Re: tachometer (Ernest Christley) ________________________________ Message 1 _____________________________________ Time: 09:01:32 AM PST US Subject: CorvairEngines-List: Re: tachometer From: D L Josephson On 10/15/15 11:56 PM, CorvairEngines-List Digest Server wrote: > Time: 06:19:00 AM PST US > From: Ernest Christley > Subject: Re: CorvairEngines-List: Re: tachometer > > There are tachs that install in series with the coil.=C2- One of those wo > uld be a very bad idea, and would concur with what you say. > However, your statement concerning the ones that sense the current bounce o > n the negative electrode does not concur with basic electronics.=C2- Unle > ss a bad tach was somehow able to burn the short wire going from the coils > negative terminal to the firewall, there is nothing it could do to affect t > he coils operation. It doesn't burn the wire, it shorts it to ground, bypassing the points. What's been seen is that a bypass capacitor fails, probably due to insufficient voltage rating or poor quality, and shorts the negative lead to ground, taking the points out of the circuit. If you must use a tach connected to the ignition primary, be sure you have two ignition circuits and connect the coil to only one of them. ________________________________ Message 2 _____________________________________ Time: 12:34:38 PM PST US From: Ernest Christley Subject: Re: CorvairEngines-List: Re: tachometer Aah!=C2- Gotcha!=C2- Thank you. On Friday, October 16, 2015 12:02 PM, D L Josephson wrote: com> On 10/15/15 11:56 PM, CorvairEngines-List Digest Server wrote: > Time: 06:19:00 AM PST US > From: Ernest Christley > Subject: Re: CorvairEngines-List: Re: tachometer > > There are tachs that install in series with the coil.=C2- One of those wo > uld be a very bad idea, and would concur with what you say. > However, your statement concerning the ones that sense the current bounce o > n the negative electrode does not concur with basic electronics.=C2- Un le > ss a bad tach was somehow able to burn the short wire going from the coil s > negative terminal to the firewall, there is nothing it could do to affect t > he coils operation. It doesn't burn the wire, it shorts it to ground, bypassing the points. What's been seen is that a bypass capacitor fails, probably due to insufficient voltage rating or poor quality, and shorts the negative lead to ground, taking the points out of the circuit. If you must use a tach connected to the ignition primary, be sure you have two ignition circuits and connect the coil to only one of them. um - S - - =C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message corvairengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/CorvairEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/corvairengines-list Browse Digests http://www.matronics.com/digest/corvairengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.