|
Here's some more info.
(I'm trying to post more or less the same information on this forum and a couple of e-mailing lists. If you see odd references, that's why...)
The Generator is a Generac NP-40G.
It is a "Computer Controlled Variable Speed RV Generator".
It uses a permanent magnet rotor, which is on the OUTSIDE of, and rotates around the stator. Circuitry in the generator controls the engine speed to maintain a constant voltage out. (The circuit board controls a stepper motor, which adjusts the throttle.)
There were both gasoline and LP versions of this generator built. This is the LP version. ( I think the only difference may be the carburator. I would prefer it as LP anyways.)
The generator has electric start, and and recharges the 12V starter battery. There is also a Remote Start Panel available as an accessory. That lets you start the generator from the cab of the RV and monitor if it is running or not. I have the service manual for this generator, which includes a wiring diagram of the remote start. I would think it would be fairly easy to build a remote start for this unit.
The specs on the generator are:
rated for 3750 watts
115v
1-phase
31.3 max load amps
60hz
220 cc single cylinder, vertical shaft engine
LP gas fueled
Air cooled
Electric start
RPM range of 2200-2600 at 0 amps and going up to 3250-3910 rpm at 30 amps.
According to the manual, the generator comes with:
Fuel Lockoff Solenoid (missing)
LP Gas Regulator (missing, should be pretty standard though)
LP Carburetor (at least that's still there!)
The manual goes on to state that the installer must provide:
Vapor withdrawl type fuel tank
Primary regulator that will deliver 11 psi
I did not see any reference to a flow rate of any regulators. When I did get engine running, it was with a propane grill regulator on the engine and somebody manually opening and closing a valve on a propane tank trying to get the right flow. I believe that some regulators use the vacuum of the engine to pull on a spring to vary the flow? Any insight on that from anyone?
To run power to the electric car, I would much rather modify some sort of device EXTERNAL to the generator itself. Seems like it's a nice little generator someday. I may want to be able to keep it around for other purposes.
I am using lead-acid (AGM) batteries with the car. My idea of using the analog battery charger connected to the batteries and AC out of the generator is that it keeps it very simple. The charger itself would limit the amperage between the generator and the batteries. (The charger is designed to only "pull" so much power from the wall, or in this case, the generator.)
I would also be interested in some sort of "black box" that would go between the AC out of the generator and the batteries. It would have to be simple enough for ME to build, or at least build with the help of some local electronics friends. It would also have to limit the maximum draw on the generator.
I think that ideally, I would want to run the generator more or less full-tilt. I know that gasoline engines are most efficient when running wide open. However, that means your car is driving really fast, and even if the speed limit doesn't slow you down, are resistance eventually will. In a serial-hybrid the speed of the engine and the speed of the car are unrelated. Seems like there is no reason NOT to try to run the generator engine as efficient as possible.
What is required to rectify the AC to DC? What voltage DC do you get from 115V AC? Lets say we get that voltage, and then just knock it down to what the battery pack wants with some sort of resistor (Tom's light bulb). How we I control amp draw to keep from overloading the generator and popping the fuse? What would be an appropriate way to limit current?
Also, I was wondering what type of LP tank would be compatible with this generator. It's an RV generator, and whenever I see an RV with propane tanks on it, they look just like the type that's on my gas grill. The manual does say to use "A VAPOR WITHDRAWL type fuel tank" and further down states "Do not attempt to use any liquid withdrawl type tank with the RV generator."
-Ben
|