Hi,
I have a machine with two Solid State Variable Speed AC Electric Motor Controls.
Model: KB Electronics Solid State Variable Speed AC Electric Motor Control 15.0 Max amps 115V # K177-1015. See picture and drawing attached below. Those units control two fan motors. Both 15amp max load.
Today I turn the knob and increases or decreases the speed of a 15amp fan motor.
I have no previous arduino knowledge, but got myself the official learning kit and started learning.
Goal:
I would like to control the motor speed remotely. I was thinking using an Arduino board and a stepper motor? If I understand it correctly such motor knows its position, no additional feedback sensors needed? The tricky part is to attach such a motor on to the existing K177-1015. Best would be to maintain a "fallback" solution. Meaning I can manually change the speed of the motor the old way by simply turning a knob or a similar wheel in case my remote control fails. I noticed those stepper motors are heavy and metal brackets would be highly recommended. Application is in a rough industrial/contractor environment. Solution needs to be well protected from dust, vibration and abuse.
I will try to measure the torque required to turn those knobs. The OFF position is a bit hard to overcome. I will get myself a Beam Style Torque Wrench to measure if needed. I don't need 360 knob range, because fan runs typically near a "sweet spot". All I need is being able to remotely adjust speed around that value. Therefore 180, or a 90 degree turn may be enough.
The K177-1015 has a nylon/plastic split shaft, the knob is pushed over it. No screws etc.
Good news there is a metal face plate sliding down the heat sink. See attached picture. That means I could replace existing plate and slide a new plate with a motor attached to it downwards until positioned exactly over shaft. Then push motor over shaft and lock in place. I think metal face plate is thin enough to be temporally bend until placed in position. Actual position of shaft between the heat sink fins makes it very difficult to attach a timing belt and pulley.
Other thought was...
I could buy two additional KB Electronics Solid State Variable Speed AC Electric Motor Control 15.0 Max amps 115V # K177-1015 and install them in a separate box running them parallel. Meaning I would leave machine as is and interface directly the two 120 Volt circuits near the fan.
I also looked into Konmison VFD Drive VFD 110V 1.5KW 1HP/3HP VFD Inverter Variable Frequency Drive Inverter for Spindle Motor Speed Control (110V 1.5kw VFD), or similar. But since I have no electronic background I am a bit uncertain if that is a better approach and if if would work at all. I assume I could interface an ardunio shield to a VFD?
Any recommendations?
