So for LEDs and motors, there is some controllers available which can be controlled via 0-10V voltage.
Is it possible to just feed rc-filtered and amplified voltage for one? How well filtered does it need?
Yes, but it is easier to amplify first and do the filter after that.
The Arduino uses a PWM frequency of about 500Hz (that is low). You can enlarge that to 10V. There are mosfet driver chips and other chips that can do that. The 10V PWM signal can be filtered with a RC filter.
The amount of filtering depends on how fast the signal should change and how sensitive the device is for higher frequency noise.
Is it possible to just feed rc-filtered and amplified voltage for one?
It is but it is more complex than you need.
Use the circuit in this link:-
http://forum.arduino.cc/index.php?topic=137845.0
Or this one:
http://forum.arduino.cc/index.php/topic,12135.0.html#5
Shows a way to do it with an op-amp as well, allowing a range of input voltages .
Thanks for the replies. I did draw my self a circuit that i wish seems somewhat ok for you too.
https://puu.sh/qbtEk/121ccb6ac6.png
My guess is that i am using Ltspice right. So the output ripple at 50% duty cycle is about 19mV.
This should work for 0-10V voltage controlled devices, right?
One thing i might add is a comparator to cutoff output when duty cycle is less than 10%.
A cutoff for less than 10% is typically something for software.
I think what Grumpy_Mike and me wrote about making a 10V PWM and filter that is a lot easier. Did you see the schematic in the link of Reply #2 ?
A OpAmp can oscillate, has noise, offset, and a lot more. Filtering a 10V PWM signal with passive components is so much simpler and more stable and more accurate.
Here's Grumpy_Mike's schematic:
If you use 12V, then you could add a resistor or two diodes to lower the maximum voltage a little.
If you can't let go of the OpAmp, then there is something in between for you : a comparator instead of an OpAmp. Use a Comparator to make a 10V PWM signal and use one or two passive RC filters after the Comparator.
One thing i might add is a comparator to cutoff output when duty cycle is less than 10%.
That is what software is for.
This should work for 0-10V voltage controlled devices, right?
Only if you have a 10V psu.