---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 05/04/10: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:41 PM - Infinity grip (Mauri Morin) 2. 05:47 PM - Re: Infinity grip (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 04:41:49 PM PST US From: "Mauri Morin" Subject: AeroElectric-List: Infinity grip Bob, I'm in the process of wiring my RV-8 and have a switch on the Infinity grip to control the Airflow Performance (API) aux fuel pump. The literature on the pump says the current draw is 5 amps at 12 volts and should be protected with a 10 amp c/b. The switch in the grip is rated at 6 amp at 12volts. API engineering thinks the switch in the grip may not be able to handle the inrush current on the pump when actitivated and thinks I should use a relay which I'd rather not do. J.D at Infinity Aerospace thinks a zener diode will solve this problem and suggested I check with you for your opinion and a possible circuit. Since this combination of grip and pump has been used in a lot of RVs, I thought that, if this was a problem, it would have been solved by someone already. Mauri Morin Ronan, MT ________________________________ Message 2 _____________________________________ Time: 05:47:48 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Infinity grip At 06:30 PM 5/4/2010, you wrote: >Bob, >I'm in the process of wiring my RV-8 and have a switch on the >Infinity grip to control the Airflow Performance (API) aux fuel pump. >The literature on the pump says the current draw is 5 amps at 12 >volts and should be protected with a 10 amp c/b. >The switch in the grip is rated at 6 amp at 12volts. >API engineering thinks the switch in the grip may not be able to >handle the inrush current on the pump when actitivated and thinks I >should use a relay which I'd rather not do. >J.D at Infinity Aerospace thinks a zener diode will solve this >problem and suggested I check with you for your opinion and a possible circuit. > >Since this combination of grip and pump has been used in a lot of >RVs, I thought that, if this was a problem, it would have been >solved by someone already. API is correct in that some sort of buffering between the switch and motor is called for. It's probably a PM motor with a significant spin-up transient. The relay is the simplest. You can do it with a single transistor and a few jelly bean components too. I can sketch either. Bob . . . ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-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/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-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.