Generator: Home Brew

To see the pictures, please visit the website at TheEpicenter.com
Home Brew Power!

Building your own generator (on the cheap).

We will discuss how to build your own generator that looks something like this.
This generator was built using a 3 horse power Briggs and Stratton horizontal shaft motor, a GM 65 amp automotive alternator (with built in voltage regulator), a used car battery, a pulley and V-belt, a 12 volt cigarette lighter outlet box with fuse, a DC to AC power converter, a low voltage control switch, a scrap of 3/4″ plywood, a few scraps of 2 x 4 lumber, 4 wheels, and two battery cables. We also used a custom designed bracket manufactured for Epicenter to make it all come together in a snap.
In the photo above, we used an 8″ pulley on the motor. Subsequent testing indicates that a 5″ pulley is the correct size to use for this application. We have however, provided data (in the pulley discussion section) for 8″, 6″ and 5″ pulley sizes.
Please note that a safety guard should be installed to cover the belt and pulleys! This guard is not installed so that the photographs show the most detail! If you plan to actually use a generator of this type, Please, Please make sure you install a safety guard!

What can this generator be used for?

The basic generator (gas powered motor, alternator and battery only), can be used as a 12 volt power source. This is extremely useful for charging battery banks in RVs, campers or in out buildings. The big advantage to this generator as a charging system is the high current output of the alternator, and thus, the reduced charge time over using solar cells, or AC battery chargers. The other big advantage to using this unit to charge batteries over just charging them with a car, is that this generator uses much less gas to do the job (which is critical in an emergency). Some HAM radio folk use 12 volt equipment that can be powered from the battery until it is low in charge, and then crank up the generator to recharge the battery. The high output of this unit also makes it useful for car lots or fleets for jump starting cars.
If a DC to AC power converter is added to the basic system, then a limited amount of 120 Volt AC power would also be available! DC to AC power converters electronically convert the 12 volt DC power to 60 hertz AC power at 120 volts. These boxes just connect to the battery on the generator, and provide AC power outlets for standard household AC power.
In our first prototype (shown above), we included a 140 Watt (200 peak) power converter for doing some load testing on the generator. Although not recommended, we ran the power converter with a 150 Watt flood light, and had no problems. That load was a bit over the design limits of the converter, but it worked OK.
DC to AC Power converters are available in various output ranges. There are three sizes that would be appropriate for use in this project: Model Continuous Peak Connector # outlets Aprox. Cost

PC140 140 Watts 200 Watts Cigarette lighter plug 1 $45

PC300 300 Watts 500 Watts Cigarette lighter plug 2 $80

PC500 500 Watts 800 Watts Battery clip on 2 $120

Please visit TheEpicenter.com for more information