How Good Is The Cheapest Generator On Amazon? [Hackaday]

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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.