---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 08/15/22: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:24 PM - Reverse Engineering an Ultralight Charging System (Jared Yates) ________________________________ Message 1 _____________________________________ Time: 07:24:01 PM PST US From: Jared Yates Subject: AeroElectric-List: Reverse Engineering an Ultralight Charging System I'm puzzled by a very simple and basic charging system and I suspect that the great minds on the list might be able to help figure out how it works. The manufacturer hasn't been forthcoming about the circuitry. Here is the extent of the technical documentation that I have found so far: http://vittorazi.com/manuali/Quick_wiring_Vittorazi_Moster185_electric_starter_eng.pdf This is a small single-cylinder 2-stroke engine. The flywheel has a permanent magnet, and there is a coil at the top for generating the spark. There is a similar coil at the bottom that is intended to charge the battery. The coils are grounded to the engine case, and on the charging coil, there is a single wire that exits the coil and goes to a small potted device that is presumably a regulator and rectifier. It has three conductors: one for the coil output, one for the battery charge, and a ground. I would guess that the coil is creating an AC current with a frequency related to the engine RPM. It seems like most of the lawn mower regulator/rectifiers have two wires for the incoming AC, then one wire for the outgoing DC, plus a grounded case. What stumps me about this one is that since the gadget in the circuit only has three wires and an insulated case, it must mean the AC voltage happens between the engine ground and the single coil output wire. I haven't yet put a multimeter on the leads while the engine is running but I suppose that would be good data. Through a set of unrelated circumstances, I fried the included factory regulator circuit, and while I could buy another one from the Italians for $50, it seems like a good opportunity to better understand how this system works. It may be possible to make a better circuit, since there are complaints that the factory circuit drains the battery if it isn't disconnected after each flight. The factory system is intended for a sealed lead acid battery. My end goal is to provide some charging energy to the tiny lithium iron phosphate battery, which is the smallest EarthX with its own little BMS. Currently the battery is working fine to run the starter motor and strobe light, but I'm sure it will require occasional recharging if I don't work up some circuitry to charge while in flight. I'm tempted to try a bridge rectifier and some type of voltage regulating circuit. Any ideas? ------------------------------------------------------------------------------------- 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.