3-speed switch

E-HP · Nov 12, 2019

I'm back looking at controllers since the one I bought turned out to be defective. A few that I'm considering have a 3-way switch. I've always thought those switches simply limit power in some way (current, voltage, etc.) for the middle and lower settings, with full power on the high setting.

Looking more closely, I'm now wondering whether the switches are implemented differently depending on the controller and whether the middle setting is actually the full/normal power setting, based on reading the various product descriptions. One in particular states "Max speed up 20%. Sine wave controller's max effective flux weakening speed-up can be 20%...". I see other descriptions that don't mention flux weakening, but describe something that sounds like it.

So my question is, do most controllers with 3-way switches use some sort of flux weakening for the hi position?

John in CR · Nov 13, 2019

The middle setting of the switch is as if no switch is used. The other 2 positions short each of 2 wires to ground (the 3rd wire). How it actually plays out in use depends on how the controller is programmed for the 3 speeds.

John in CR · Nov 13, 2019

John in CR said:
The middle setting of the switch is as if no switch is used. The other 2 positions short each of 2 wires to ground (the 3rd wire). How it actually plays out in use depends on how the controller is programmed for the 3 speeds. When ordering controllers, I always request that the default (position 2, nothing shorted to ground) is 100% speed, and don't worry about the 3 speed switch. They are cheap little switches prone to failure.

If I get a controller already programmed for 3 to be top speed, then I just permanently hardwire the appropriate wire to ground.

john61ct · Nov 13, 2019

Is there any scheme where that sort of adjustment affects the power distribution at a given power level, to favour rpm vs torque?

So level 1 for extra strength at lower speeds, 2 for default / normal, 3 for getting a higher top speed?

MJSfoto1956 · Nov 13, 2019

Speed #1 can best be described as "valet mode" -- slow acceleration and low top speed (with maximum distance)
Speed #3 can best be described as "ludicrous mode" -- extreme acceleration and max top speed (with a significant loss of distance of course)

Speed #2 is your normal mode -- decent acceleration and top speed with "normal" distance.

M

E-HP · Nov 13, 2019

john61ct said:
Is there any scheme where that sort of adjustment affects the power distribution at a given power level, to favour rpm vs torque?

So level 1 for extra strength at lower speeds, 2 for default / normal, 3 for getting a higher top speed?

That's basically what flux/field weakening does, so the trade off for the higher speed is much higher power consumption. I'm just wondering if most controllers with a three speed switch (e.g. Kelly) actually apply flux weakening in the high position, but just don't state it.

fechter · Nov 14, 2019

E-HP said:
So my question is, do most controllers with 3-way switches use some sort of flux weakening for the hi position?

I don't think so. Most are too cheap to have flux weakening.

I have a Powervelocity controller that you can program the settings for the 3 speeds. Current limit and speed limit are programmable as is the flux weakening.

neptronix · Nov 14, 2019

fechter said:
I have a Powervelocity controller that you can program the settings for the 3 speeds. Current limit and speed limit are programmable as is the flux weakening.

Similar to my array of oldschool infineon clones. I really like having that 3 speed switch. More advanced controllers that use Sine or FOC tend to not have that feature. Or the proposed alternative is to use a CA V3, which is a piggy back controller that doesn't have as much of an instantaneous response as making these changes at the controller level.

3-speed switch

E-HP

10 GW

John in CR

100 TW

John in CR

100 TW

john61ct

1 TW

MJSfoto1956

10 kW

E-HP

10 GW

fechter

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neptronix

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