Thank you all for replying !!!!!!!!!
I went through some DC motor control devices and have some ideas and questions.
I thought of a device that can control motor speed of DC motors that has a range of supply voltages. The device will have an encoder input that can detect the motor speed as well as a 4-20mA current loop input so that the motor can be used to control other processes (eg - flow rate). PID autotune function. Plotting the speed vs time on a LCD screen or on the PC.
These are some of my ideas. I do not know whether they are useful, doable, easy or hard. I would verymuch like your input.
Regards.