Hello! I need to control an electromagnet with pwm. As it is an inductive load, i believe it's not a good option to use plain pwm. My supply voltage will be 24v and i need to get the voltage output for the magnet around 2-6v and it needs to be adjustable. Pwm+rc filter? What are my options? I would rather like to build it myself vs just buying something ready made. Last option (but i belive it would work) is an RC brushed ESC.
What about current (Amps), resistance (Ohms) and power (Watts)? How will you switch the 24V?
No problem. Use PWM with a (logic level) MOSFET and a freewheel diode. Be careful with the duty cycle, it should not be higher than 25% for 6V from 24V.
Sorry, forgot to mention the current. It shouldnt be more than 2a @6v. Ideally the control would be with pwm somehow. I also have a hall sensor input to control another pwm and the inductive load needs to be set according to that and some other variables. Any example circuits would be appreciated
PWM works perfectly with inductors - that is how a switchmode power supply works. 
Not only do you not need to filter the PWM, it is totally inappropriate to do so as the inductor itself performs the filtering.
Now you do need to understand a few things if powering a 6 V solenoid from 24 V.
- You absolutely must have the "freewheel" or commutating diode.
- You must ensure that the PWM can never rise beyond the set proportion such as the FET being "stuck" on.
- The PWM frequency must be reasonably high so that the inductor current never rises toward its maximum (limited by its resistance).
- The solenoid will be seeing pulses of the full 24 V. This is unlikely to be a concern.
- You must have a bypass capacitor perhaps 1 mF (often quoted 1000 µF) across the supply at the connection of FET and commutating diode.
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So, you mean i need a cap and an diode on mosfet S-D? It will actually be driving an alternator field coil, trying to build control for motor conversion. I dont think that over 6v on it would hurt it but it doesnt need more. 2-6v should be enough
What you are looking for is a power-driver circuit:
Car Alternators Make Great Electric Motors; Here’s How | Hackaday
Summary for haters of linked articles:
The good news for people converting automotive alternators into electric motors is that a whole range of brushless motor controllers can be had for not a lot of money, in the form of electronic speed controllers (ESC) intended for those Chinese electric bicycles and tricycles. They take a battery DC supply and produce a three-phase AC suitable to drive a delta-connected motor, and they work well with converted alternators.
ESCs have two modes, one for motors with Hall-effect feedback sensors, and one for motors without such as our alternator. Usually a wire link needs to be made to enable this, consult the instructions for your controller. We’ve found that an alternator drives well as a motor from a 36V or a 48V supply, and as long as a controller with enough power is used then they do so reliably. A quick AliExpress search for “brushless motor controller 1500W” turns up plenty of choice.
I know those escs, but i want to control the field current as more voltage means more torque and less voltage is for more rpm....
The diode goes across the coil, the decoupling capacitor across the supply. Nothing goes across the MOSFET source-drain. Example circuit: https://arduinodiy.wordpress.com/2015/12/29/using-fets-to-switch-a-load/
Looks good.
Note that using PWM, the current through the coil is - as is intended - relatively constant but the current in the FET, diode and decoupling capacitor is switching rapidly with the PWM. This means that you need to keep the FET, diode and decoupling capacitor as tightly together as possible but the inductor (your field coil) may be some distance away.
A common mistake is to imagine that the diode needs to be close to the inductor; in reality it is important that it is close to the other two components. And of course, for PWM, the diode must be a "fast recovery" type such as a Schottky.
The decoupling capacitor needs to be substantial - at least a few mF (few thousand µF), and rated for the coil current.
Should i use plastic cap or one of those metal "cans"?
For what? 
You'll only find electrolytic caps in that sort of value. Electrolytics have much higher energy density. I presume you are describing film capacitors and electrolytic capacitors.
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