The YellowBoard's latest annoying IoT (Internet of Türklingeln) device is an old-fashioned door bell.
As the bell's electro magnets need AC TomK32 hammered a 7.5V DC power supply and removed its puny diode bridge. The low AC is now fed into the bell as well as through a beefy 3A diode bridge. The ~10V DC is connected to a buck converter and suppling enough power for all the ESP devices on the YellowBoard. This will make all other power supplies for the board redundant as the setup (not sure about the transformer) should allow for 5A.