The low voltage ripple capacitor, type ELKA are used as tuning capacitors in combination with inductors to generate the appropriate ripple frequency at the transmitter side. The capacitor is
single phased but with multiple taps.
The high voltage ripple capacitor, type ELNA are used as coupling capacitors on the network side to compensate the voltage drop, while transmitting the ripple signal into the network. The
capacitor is single phased and it is floating or have a midpoint connected to the tank. Fundamental frequency is 50 or 60 Hz.