Sorry I sent the message too soon. Getting max power out of an engine means running it at a pathological where the load is exactly matched of just one RPM. But youengine is over powered as it should be so you only need to run a wide open throttle at any RPM where thecurve is able 3.5 (or whatever) HP.
You are still going to need two automatic control systems or a full-time skilled human operator. 1) the first control system measures battery voltage over time and computesthe rate of charge and uses a MOSFET switch to limit rate of change. All current battery charges today use a microcontroller and software to do this. Again a skilled human operator could watch a meter and maybe move switches if it had charge rate chart as reference. This is best left to automation. 2) You are going to need an RPM sensor on the motor and an actuator on the throttle so that RPM stays constant ouder different loads. Or maybe smarter use an algorithm that runs the engine at the minimum RPM needed to produce the power required. Again a microcontroller and software is needed. Or a skilled full time human operator. One other thing. The battery charge controller will produce a varying load. At first, it will "bulk charge" and then taper off the power delivered to the battery. I'd thing it a good idea if the battery charger software could communicate to the engine controller software. But this is a "version 2.0 step. You likely also want a display so you can monitor what's happening inside. Certainly during development you need to watch it closely while you do things like tweak PID constants and the like. If the control computer where something like a Raspburry Pi it could put all the data on a web page. Then you can remotely monitor the charger over WiFi on your phone or desktop computer. In the old days they used mechanical governors with pushrods to the carburetor for RPM control but today you put a rotation sensor on the output shaft that does a pulse each revolution and send that to the engine controller On Mon, Jul 12, 2021 at 9:02 AM Chris Albertson <albertson.ch...@gmail.com> wrote: > The 6.5 rating on that engine is at "wide open throttle" at the RPM tha > produces peak power. > > I don't know the power curve of that engine but its peak power speed is > likely faster than you want to listen to, 6,000 RPM maybe. Your first > step is to use the correct pulley ratio to let the engine run at its peak > powerpoint. The next step is to implement some kind of automatic throttle > unless you want to manually operate it. > > On Sun, Jun 27, 2021 at 4:44 AM fxkl47BF via Emc-users < > emc-users@lists.sourceforge.net> wrote: > >> i'm gonna explain my screwup here because this group of folks has a very >> diverse range of expertise. enough kiss'n up. if you know of a list that >> would be more appropriate please let me know. >> i've had a desire for some time to build a gasoline powered battery >> charger. i've seen it done several times and thought no big deal. my first >> thought was to use a 3 hp engine and a 100 amp one wire alternator. but >> since i already had a 6.5 hp engine i decided to go with that and an >> alternator like this >> https://www.ebay.com/itm/NEW-CS130-ONE-WIRE-RED-ALTERNATOR-FOR-CHEVROLET-GMC-CHEVY-220-AMP-1-WIRE-1100665-/283190864732?hash=item41ef7dab5c. >> i also added an ammeter like this >> https://www.ebay.com/itm/301111474999?hash=item461ba47b37:g:hYUAAOxy4fVTEuR6 >> . >> i finished it and was ready to test. i pulled a big battery out of my >> tractor, connected a 1000 watt inverter, and about an 800 watt load. i >> cranked the engine and connected it to the battery. ammeter showed about a >> 7 amp load. i switched on the inverter and it went to about 9 amps. i >> switched on the load and it went to about 75 amps. the engine was >> straining. i disconnected the the alternator from the battery so the load >> could draw down the battery. after about one minute i reconnected the >> alternator. the ammeter jumped to about 110 amps and it promptly stalled >> the engine. i tried several times with the same results. >> all of my feeble calculations led me to believe that a 6.5 hp gasoline >> engine was more than enough to power a 220 amp 12 volt alternator. either >> my 6.5 hp engine is more feeble than my brain or my calculations are way >> off. >> thanks for any feedback. >> >> >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > > > -- > > Chris Albertson > Redondo Beach, California > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
