OF2200 router power issue?

[Rick Christopherson]

More generally, fancy underlying issue with tools that maintain their speed, regardless of load,
is tied up with the power-factor varying as the tool adjusts itself.
As RickC suggests, this can cause a tussle with the genny if under-powered.
My understanding of what can happen is, that when the tools are turned down,
that that will create (almost counter-intuitively) a sudden 'blip' of, surprisingly high,
current demand, from the generator due to the power-factor dropping.

Variable speed motor controllers use Pulse Width Modulation (PWM) to control the power to the motor. They do not alter the powerfactor. That is a completely different electrical term that is not really related to this.

Years ago, the only (common) way to reduce power was to reduce the voltage. That is how your old lamp dimmers worked--they had a variable resistor that reduce the voltage to the load. That was very inefficient, wasted energy, and created a lot of heat in the dimmer.

A more efficient way to control power is to completely turn it off or completely turn it on. You don't waste energy trying to get it somewhere half-on. You can even see this with your own light switches if you're fast enough. If you can turn your light switch on and off fast enough, it will appear to always be on, but just dimmer than normal. That's the basis for PWM.

While rapidly flipping the light switch on and off, if we can control how long it stays off versus how long it stays on, then we can control how bright the light will appear to be. That's exactly what PWM controllers do for controlling the power to motors. The total time from off-on-off doesn't change, but the ratio between the on and off does change.

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The inverter-generator is actually doing the very same thing, but at a much faster rate to simulate the sinewave. It is probably turning on and off 10,000 times a second (10kHz). It is the interference of these two switching frequencies that is messing up the ET-TEC controller. It is complicated to explain in less than a gazillion words, but the high frequency switching in the inverter-generator is turning off the power transistors in the EC-TEC module before they are supposed to turn off. That is why you see a loss of power from the tool.

 

[Taylorkitchens]

thank you for all the help and info Rick, i managed to pick up a stephill 5kva/4kw 9hp honda generator and it works a treat. i can spin the speed dial up and down all day and it didnt faulter

Richard - i managed to try it a huntingdon plant hire as they were selling a 3.4 kva genny and that was crap as well but they had a 6kva one they let me try and it was spot on like the 5kva. theres only 800watts between them so i knew thats what i needed. 

but has made me chuckle, bought the router from the local dealer for £660 and a new jig which totaled £750 and then another £335 just to be able to run it! HA