The more common approach to manipulate the incoming AC wave so that both halves are used to cause output current to flow in the same direction is the use of full-wave rectifiers. A full-wave rectifier ...

Helium-filled full-wave rectifier. A 4-pin base with brass shell and ceramic insulator. Tipped S-shaped envelope. Serial number "5144". Two ceramic-covered cylinders are set side by side on top the ...