Why not just use a pwm frequency of less than 1hz as has been suggested above. The thermal mass of the heating element is so large that high pwm frequencies are not reqired. You won't need any kind of filter then.
Why not just use a pwm frequency of less than 1hz as has been suggested above. The thermal mass of the heating element is so large that high pwm frequencies are not reqired. You won't need any kind of filter then.