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How does one calculate or determine the optimal PWM Frequency.
What factors influence to help to find the optimal frequency and do they exist.
What are you PWMing? Some more information is needed to provide an answer based on the application...
01-15-2009, 09:16 AM
Generally, inductive loads need a LOWER frequency due to a number of factors. One being there is more energy lost in the circuit if the frequency is high. This is due to the inductor having to dissipate the built up current when the switch turns off. This current is usually dissipated in a diode, which generates heat.
Resistive loads can usually be any frequency. The power lost here is simply in the switching transistion(usually mosfets).
I am using a solenoid valve to open and close (air valve) - it has to close and open at various levels from
beingg totally close to totally open and all ranges in between.
The Solenoid coil is 11 Ohms and rated at 5V d.c. Pressure from 1-50 psi.