Generator field control

[btahir90]

I am working on a project which is Automatic voltage regulator of fenerator using field contol through PWM

problem is what should be the frequency of PWM

generator draws 1 A at 50v dc field at full load and 0.5 A 19 v at no load.

my idea is to choose a mosfet and a diode to prevent transients. pwm directly from microcontroller. would it work?

 

[ArNvC]

What are the specifications of the motor you are using?

my idea is to choose a mosfet and a diode to prevent transients.

where is your circuit?

 

[btahir90]

its not a motor its an alternator of 2.5kw . i need to control its terminal voltage with field current.

- - - Updated - - -

here is cicuit diagram
mosfet using is IRF740
frequency to choose is 1kHz.

 

[ArNvC]

Is the circuit working?
your pwm frequency should be optimum where losses would be low