Pulse Modulation


Thread Starter

Dave van Rhijn

Dear members,

PWM - Pulse Width Modulation on logic controllers?

More useful or successful than simple analogue signal control?
What are the applications different manufacturers may use this for?

Dave van Rhijn

Audun Alvestad

Hi there!

PWM seems meaningless at first but I am actually using this as a feature in my regulation system.

My system monitors and supply the oxygen for fishfarms. By using PWM on the valves that regulates the O2 supply you will get a very good regulation. Why doesn't you use prop.vents you may ask, MONEY?

Typical system for fish farming have 20-30 regulation points. prop.vent costs the tripple of ordinary magnetic valves and the costs of analog output the same.

Basic: PWM reduses the costs to 1/3!!!!!

I'm using Moeller PLC

Heavner, Lou [FRS/AUS]


First thing that comes to mind is resistance heaters. Possibly some stepper motors or motorized valves are designed for PWM.


Lou Heavner
Emerson Performance Solutions
We use PWM to directly drive hydraulic proportional valves to control speed and
position. This eliminates the need for an analog output and valve driver board.
You can also make a reasonably good unipolar analog output by low pass filtering the pwm.

Bill Marsh
Integrated Controls

Tycon Automation pvt.

we're using pwm for temperature control
in plastic moulding.

Tycon Automation pvt. ltd.
201, sethi bhawan
7, rajendra place
new delhi 110007