ResMed S8 machines with a Humidaire heated humidifier are required
to use a pure DC-to-AC power source. The Humidiare humidifier is disabled when using the DC-12 Converter For S8 Machines
An inverter converts DC battery power to AC wall power. ResMed humidifiers can become damaged if the battery power is not inverted into a clean AC power source. Most inverters do not generate a pure signal from a DC battery and the Humidaire heated humidifiers are susceptible to power spikes. The 'Pure Sine' refers to a signal wave with controlled peaks and dips. Power signals that rise or fall erratically are dangerous to electronics.