I have a device that is powered from a current source. The current source supplies 10A at 60Hz - the magnitude is roughly 5-10VPP.
I would like to inject another signal on top of that to simulate noise or data at a high frequency.
I am powering my device from the power line current through a CT, and I am also measuring the current through another CT.
Ideally I would like to be able to measure the frequency response of my power input circuitry to see what my passbands are at the input to my power supply, and I would also like to see what my passbands are at my ADC input.
So here is my harebrained Idea:
As you can see, the point between the two diodes should be DC Biased to 12V. There should be no DC current though. But because that section is biased up, the diodes should block any of the signal from flowing back into the current source or back into the source on my spectrum analyzer. Then I would strip the DC off using some arbitrary low valued power capacitor. I would effectively be floating my current source to a virtual ground 12V above my system ground. To do this I would need to use a cheater plug. If I tie the negative terminal of the battery to system ground and to the output tab of my UUT and tie the positive tab of the battery to the tab on the cheater plug I think this effectively makes the battery part of my AC current path which may be a problem. Anyone think this will work?
The only other thing I can think of is building some LC PI filters - one a high pass from the analyzer source, and then a low pass from the current source. I need to pass several amps of current though so I would need to keep the impedance down on the low pass. But that could be an option.
EDIT: Here is the type of current waveform I want to drive into my system. Note that I want to sweep the frequency on the higher frequency component.
As of right now I leaning towards using a high current buffer amp w/ summing amp input to do this and ditching my existing current source. I can't figure out how I would wire up the above circuit to float my current source without burning the building down.