I have a project which is powered by a 40 V lithium battery. I then use an H-Bridge to turn it into an AC signal to feed a transformer (at around 20 kHz). The transformer steps up the voltage to around 2 kV to power a transducer. It draws a lot of power, approximately 1 kW RMS.
I used a thick shielded cable (maybe 10 ft) from the transformer to the transducer. To where should I bond the cable shield? Should I bond it to the negative terminal of the battery? Should I let it just float? I imagine bonding it to one of the legs of the transformer would defeat the purpose of the shield.
I did a search on the forums and see that bonding to the DC ground is best, but in my case the shield is after a transformer and I am worried about noise being fed back to the circuit. The control side is also powered by the same battery.
Side concern: I am also really worried about interference to the low voltage (5 V) control side. Even though I put in a ground plain, avoided circuit loops, and put capacitors near every chip, I am worried about the 25 amps flowing across the H-Bridge. I have actually built the system and it works fine but it still worries me. Any suggestions or best practices would be very welcome.