On a system I'm working on there are numerous subsystems which share common VDC+ VDC- and GND buses. A few of the subsystems are injecting noise onto the supply buses. They all have a bunch of LEDs being driven by PWM at audio rate (WHY??) and they aren't very well bypassed internally -which can present as a problem for some of the other subsystems (sensors etc.). So my plan is to add passive inline T-filters between the noisy systems and the supply buses.
I'd like to be able to simulate a few different designs (different loads & prominent frequencies) but I'm not sure whether I'm on the right track with my model or not.
Starting with just one of the subsystems being powered, I was able to measure the DC average current draw, as well as the transient current draw.
Am I right to think that I could model the subsystems loading effect as an equivalent load resistance in parallel with an alternating current source?
Example: Vbus = +12V, DC load current = ~200mA Transient current = 50mA @ 1000Hz
Power supply is to the left, the subsystem being powered is to the right, and the boxed area contains the filter I want to add.