Abstract: This invention relates to a multi-room air conditioning system with a plurality of indoor expansion valves. A method for sequencing the initialization of each indoor expansion valve upon system startup is disclosed. The method includes the following steps: 1. Initializing expansion valves corresponding to active indoor units, 2. Turning on the compressor, 3. Adjusting the indoor expansion valves corresponding to active indoor units, 4. Initializing and adjusting indoor expansion valves corresponding to inactive indoor units.

Abstract: If an operation command is received from any of the indoor units when the initialization of the corresponding electronic expansion valves is not completed. First, initialization is performed on the electronic expansion valve corresponding to the indoor unit which has issued an operation command. When the initialization has been performed on the electronic expansion valves corresponding to all of the indoor units which have issued an operation command, the flow proceeds to a processing step for a compressor. Then, the electronic expansion valves which have been initialized are adjusted to a predetermined operational opening degree. After this step is completed, the electronic expansion vales corresponding indoor units which have issued no operation command and whose initialization has not been completed are initialized and adjusted to a predetermined opening degree. This leads to a reduced loss of time until the compressor is activated after the electronic expansion valves are initialized.

Abstract: To provide a capacitor drop type power supply circuit that can withstand a surge-current generated at power-on by use of inexpensive elements without requiring a complicated circuit configuration. A capacitor drop type power supply circuit includes: an AC power supply (1) connected to a series circuit of a resistor (2), a first capacitor (3), and a first diode (4) whose cathode is connected to the first capacitor (3) ; a series circuit of a second diode (5) and a Zener diode (6), which is parallel-connected to the first diode (4); and a second capacitor (7) parallel-connected to the Zener diode (6), the circuit outputting a DC voltage generated across the second capacitor (7).