Inverter Weirdness

Was camping last week and decided to take advantage of the inverter in the bed .That's right, some freshly ground java!

Before bringing the coffee grinder I measured it's pretty consumption which was about 110W and .8PF. this should not be a difficult load for a 400W inverter. The grinder does not use an on/off switch rather a momentary push button to start the timer. When using on the power inverter it would time out in about 50% of the expected time. The lights on the dash button were both on and steady even when the grinder stopped. Has anyone else experienced this?

As it does not seem like the inverter if faulting out from the inductive load I think it may be waveform related (this theory holds up if the timer I. The grinder is digital and/or diciplined by the lights e frequency). Perhaps the outlet is giving a higher frequency output (unlikely as this would make many magnetics transformers operate poorly). This could also be a result of a quasi sine operation where only 5 different voltages levels are used to approximate a sinewave. If this is the case a quasi sine wave has tones of harmonics (dirty power) and these harmonics are causing false counts of the timer to accumulate (poor filtering on the coffee grinder circuit design) or it's just noisy enough to cause the whole circuit to reset.

Had anyone taken a scope to the inverter output? It's too wet out today to do safely but I plan on doing this when it dries up some.

 

Did you measure the grinder without beans being grounded? The grinder could be drawing more with actually beans in it when grinding.

 

Beans were in it.