How Good Is The Cheapest Generator On Amazon?

Although an internal combustion engine-based generator isn’t exactly one of the most complicated contraptions, any time that you combine something that produces power with electrical devices, you generally like to know how safe it is. Even more so when it’s a $139 generator you got off Amazon, like the PowerSmart 1200 Watt (1000 continuous) that the [Silver Cymbal] took a gander at recently. They used an expensive professional power analyzer to look at more than just the basic waveform of the 120 VAC output to figure out what kind of devices you’d feel comfortable connecting to it.

Waveform analysis of the cheapest generator when under load. Looks better than with no load attached.

On the unit there is a single AC output, which a heater got attached to serve as a load during testing, but before that, the properties out of the output voltage were analyzed without any load. This showed a highly erratic waveform, as the generator clearly was unable to synchronize and produced a voltage within a wide range, immediately disqualifying it for connecting to sensitive electronics. Things got less dire once the load was hooked up and turned up to use up a big chunk of the available continuous power.

Although being far from a perfect sine wave, the output now looked much better, with all properties including the total harmonic distortion (THD) being just a hair over 20% and hitting just over 60 Hz on the frequency.

Definitely not a great result, but as a cheap unit to keep around for powering things like heaters and power tools that aren’t too fussy about how clean the power is, one could do a lot worse.

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Two hands hold an electric motor rotor and a 3D printed coil structure next to each other. A multimeter in the background displays 297.0 mV.

ModuCoil – A Modular Coil For Motor And Generator Projects

While renewable energy offers many opportunities for decentralizing energy production, it can sometimes feel that doing so on a truly local level remains unachievable with increasingly large utility-scale deployments re-centralizing the technology. [AdamEnt] hopes to help others seize the means of energy production with the development of the ModuCoil.

This modular coil is intended to be used in motor and generator applications, and features a 3D printed structure to wind your copper about as well as a series of ferromagnetic machine screws and nuts meant to boost the field strength. This project really emphasizes the rapid part of rapid prototyping with this version 2 of the coil following only a week after the first.

[AdamEnt] only reached a peak of ~600 mV in the short test of a single coil, but is optimistic the current design could hit 1V/coil given a fully wound coil actually affixed to something instead of just held in his hand. It’s definitely early stages, but we think this could be the start of an interesting ecosystem of motor and generator designs.

If you want to learn more about how those big wind turbines work, look here, or you could check out a 3D printed brushless motor, or where all that copper comes from anyway.

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