I need a z-wave controled potentiometer and got a suggestions that one could use a Zuno and a MCP41010 - anybody that already have tried this and can share some experiences, a schema how to connect it together etc?
I need this to control an EC motor (in a fan) that has a built in potentiometer (0-10V) but also supports external 10K Ohm potentiometers. Ideally I would also like a normal mechanical potentiometer to manually control the resistance if the automation is not working but not absolutly needed...
Any other sugestions on how to solve this are of course also appreciated
Anything special I need to think about electrically when using a dimmer instead of a potentiometer - i.e. an independent 0-10V source rather than the EC motors own 10V source powering a potentiometer?! I need to use connon earth I assume but in additional to that?
If your requirement is to control your EC motor via Z-Wave, my advice is to buy the Qubino flush dimmer and do testing with a voltmeter to verify it behaves as expected since an EC motor is expensive. Although I'm pretty confident the product will work based on its support for a temperature sensor and PID controller logic (i.e., it was designed to do more than dim lights based on a manual input - it can sense an ambient condition such as illumination and temperature and automatically change the output voltage using an impressive number of configurable parameters), this is not a project for blind trust.
As for an electrical connection, yes, you'll want to connect the EC motor's control ground to the Qubino's output ground. I see the Qubino needs a 12-24 VDC power input, which you'll have to provide (it's unlikely the EC motor has the appropriate power output so you'll likely need an AC to 12VDC power adapter). Having a voltmeter is important to verify the control voltages using the Qubino match the voltages using your existing controller speed controller. Ideally, you'll configure the Qubino to match the minimum and maximum voltages so that the EC motor will be none the wiser. You should also be able to retain manual speed control by connecting your existing controller to the Qubino input leads.
Thanks for many good points and yes the fan is $300+ so I for sure do not want to destroy it. Would it make sense to put a say 100 Ohm resistor in series with the Qubino to reduce the risk of overcurrent to the fan speed controller?
I doubt a resistor is necessary or appropriate - the specs for the Qubino state a maximum sinking current of 2 mA (pretty small - not enough to light an LED). I have a minor concern that the EC motor might draw more than 2 mA on the control input (i.e., exceeding the capacity of the Qubino). If you have the specs for your EC motor, it may state the control circuit impedance. However, I think there's an easier/better approach using your external controller- just measure the control circuit current flow using a multimeter at low, medium and high speeds. A typically microcontroller GPIO input impedance is around 50k ohms (0.2 mA draw) which means a resistor (if used) should be no more than 10 ohms (this assumes your EC motor control circuit impedance is similar to a typical microcontroller GPIO impedance). If you don't have a multimeter, I suggest buying one on Amazon - perfectly good ones are under $20. I would not undertake this project without a multimeter to test for voltage and current compatibility. With a little bit of testing, you'll know if the Qubino product will work for you. If I was in your shoes, I would do the same testing for any third-party EC motor controller (a light bulb is cheap - an EC motor is not).
