Quick question on what industry uses proportional pwm speed control
sport270
Posts: 82
in BASIC Stamp
I used a pwm control from a proportional brake control and just used a pot to dial it in to the voltage i needed to make a suar danfos h1 hydrostat pump output the flow needed to achieve a given rpm.... works but operator is having to adjust it when first started up and cold hydraulic fluid, then again when heated up.... was wondering easiest way to add proportional control to keep rpm constant. Or even better ... a off the shelf pwm control to do this... as volume needed is only around 10 needed. And this is on 12dc mobile equipment
Comments
If instead it's the hydraulics that isn't consistent then you're probably looking at needing feedback to form a servo loop from.
A simple PI controller can increment the PWM time when below the desired RPM and decrement the time when too fast. Put it in a timer loop, and tune the response using the timer value.
Retain the pot to vary the target setpoint as needed.
Many commercial PID controllers will accept pulses like this for an input.
These sensors will work for sensing gear or sprocket teeth, or even a keyway: http://www.motionsensors.com/speed-sensors/variable-reluctance-speed-sensors.shtml
Many of the small PLCs in the 'Smart Relay' category have frequency counter capable inputs and PWM capable outputs. Check TriPlc.