SWITCH FAILURE MONITORING IN AN ELECTRICALLY HEATED SMOKING SYSTEM

摘要

There is provided a method of controlling an electric heater (14) in an electrically heated smoking system, the method comprising: providing electrical power to the heater in pulses such that during an active periods power is supplied to the heater and during inactive periods power is not supplied to the heater; charging a capacitor(52) in an RC circuit (36) during inactive periods and allowing the capacitor to discharge during active periods; and monitoring a discharge voltage of the capacitor and if the discharge voltage of the capacitor drops below a threshold voltage level, then stopping further supply of electrical power to the heater. This method allows for consistent and reliable detection of a switch failure using compact and low power components.