Coupling AC and DC magnetic fields

[spitzbubchen]

Hoping that one of you electrical wizards may be able to help me out!

I have a 30A DC HP power supply and a 1000W stereo amp that I want to use create a 10mT static DC magnetic field superimposed on top of a 1 mT AC magnetic field. To generate the AC field I have a 1 uF snubber cap. in series with my magnetic coil so that they resonate at around 1300 Hz (to overcome the massive inductive resistance). Using the SAME magnetic coil I want to couple my DC power supply into this circuit. What is the best method of doing this? I thought I could send my DC through a choke (inductor) and into the circuit right behind the cap., but such power chokes are massive and really expensive!

Thanks

 

[zomgineer]

You could make a simple amplifier using the DC source and a power transistor after the snubber cap. It could designed to have a gain of one if you don't want to amplify the 1300 Hz signal any more than it is. Simple amplifiers will naturally have a DC offset and it actually takes a bit of work to get rid of the DC in the output. I'm not an amp pro so I don't know off the top of my head which particular transistor configuration will suit your needs best.