I’m using an 12 volts and 35 ohms electomagnet.Using Gammon’s circuit below.I’ve set pwm 30Hz to get a precise control(To make big duty cycle control).Because of the PWM’s On/Off cycle electromagnet vibrating so much and its very noisy.I want to smooth PWM to analog so there will be no vibration.But not just for the vibration i think it will be stronger with analogue voltage.
I’ve searched the PWM to analog ways and i saw 3 ways;
1-With a DAC chip.I dont want this because of its low resolutions comparing to other two.
I want a good control and dont want to make it wrong.I havent an oscilloscope so im afraid to make something that works in the naked eye but actually it’s wrong and will make problems by time.You know electromagnet have an impedance and resistance and they are confusing me.
1-Which filter i have to use?Does it much matter?
2-How to determine the values of filter?For a quick reponse like 30hz?I just want to calculations
3-I will apply this filter between +12volts and electromagnet am i right?
My power supply for 12volt is an 1A adapter(like phone charger).And mosfet is FDS9926A Datasheet Electromagnet is 25 kg sucktion 35 ohms, maximum 12volts.