Test: Common Mode Choke UNLISTED

The sim shows a 5VDC supply and a common mode protection to hold the DC circuit close to GND, but deliberately not fully grounded, monitored by two 3mm LEDs. This solution may not be sufficient to fulfill legal requirements.

My simple DC supply (SMPS, USB charger) from 230VAC to 5VDC shows heavy common mode noise in respect to ground. The main component is 50Hz. As the DC wiring of my application extends to some feet length the whole circuit must be grounded / monitored to prevent it from reaching dangerous voltages (personal, wiring and component protection).

This circuit also protects from interference with mobile phones, but it’s difficult to say in what extent ....

The switch connects to GND to show the difference between unprotected / protected common mode voltage.