Air compressor and method for controlling the same

An air compressor, comprising:

• a tank portion for reserving compressed air used in a pneumatic tool;
• a compressed air generation portion for generating compressed air and supplying said compressed air to said tank portion;
• a drive portion including a motor for driving said compressed air generation portion;
• a control circuit portion for controlling said drive portion;
• a temperature sensor for detecting the temperature of said motor of said drive portion;
• and
• a pressure sensor for detecting pressure of compressed air in said tank portion,
• wherein said control circuit portion controls a rotational speed of said motor based on a detection signal output from said temperature sensor and a rate ΔP/ΔT between pressure change ΔP and time ΔT.

An air compressor, comprising:

• a tank portion for reserving compressed air used in a pneumatic tool;
• a compressed air generation portion for generating compressed air and supplying said compressed air to said tank portion;
• a drive portion including a motor for driving said compressed air generation portion;
• a control circuit portion for controlling said drive portion;
• a voltage detection circuit for detecting a power-supply voltage of said drive portion;
• a current detection circuit for detecting a load current of said drive portion;
• and
• a pressure sensor for detecting pressure of compressed air in said tank portion,
• wherein said control circuit portion controls a rotational speed of said motor based on a detection signal output from at least one of said voltage detection circuit and said current detection circuit and a rate ΔP/ΔT between pressure change ΔP and time ΔT.

A method of controlling an air compressor, including a tank portion for reserving compressed air used in a pneumatic tool, a compressed air generation portion for generating compressed air and supplying said compressed air to said tank portion, a drive portion having a motor for driving said compressed air generation portion, and a control circuit portion for controlling said drive portion, said method comprising:

• detecting a temperature of said motor of said drive portion by a temperature sensor;
• detecting a pressure of compressed air in said tank portion by a pressure sensor;
• and
• controlling a rotational speed of said motor in at least three stages of high speed, middle speed, and low speed based on a detection signal output from said temperature sensor and a rate ΔP/ΔT between pressure change ΔP and time ΔT.

A method of controlling an air compressor, including a tank portion for reserving compressed air used in a pneumatic tool, a compressed air generation portion for generating compressed air and supplying said compressed air to said tank portion, a drive portion having a motor for driving said compressed air generation portion, and a control circuit portion for controlling said drive portion, said method comprising:

• detecting a power-supply voltage of said drive portion and a load current of said drive portion;
• detecting a pressure of compressed air in said tank portion by a pressure sensor;
• and
• controlling a rotational speed of said motor in at least three stages of high speed, middle speed, and low speed based on the detected power-supply voltage and detected load current and a rate ΔP/ΔT between pressure change ΔP and time ΔT.