Linear compressor control circuit to control frequency based on the piston position of the linear compressor

• US 5,947,693 A
• Filed: 05/01/1997
• Issued: 09/07/1999
• Est. Priority Date: 05/08/1996
• Status: Expired due to Term

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Yang, Soon-Bae
• Primary Examiner(s): Freay, Charles G.
• Assistant Examiner(s): Evora, Robert Z.
• Application Number:
  US08/848,919
• Time in Patent Office: 859 Days
• Field of Search: 417/44.1, 417/45, 417/44.11, 318/254, 318/139
• US Class Current: 417/45
• CPC Class Codes: F04B 2201/0201 Position of the piston
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04

Abstract

A linear compressor operating apparatus includes a rectifying and filtering unit for converting an alternating current into a direct current, an inverter for inverting the direct current outputted from the rectifying and filtering unit into a desired frequency alternating current for operating a linear compressor in accordance with the alternating current outputted from the inverter, a position sensor for detecting a position of a piston of the linear compressor and outputting a position signal in accordance with said detection, a current detector for detecting the current running through the linear compressor, and a controller for receiving a current signal outputted from the current detector and a position signal outputted from the position sensor and outputting a pulse width modulating signal to control the inverter. The apparatus obtains a constant value of an interval which determines the efficiency of the linear compressor, regardless of a load thereof and optimizes a phase angle between the driving current and the compressor piston.

Claims

1. An apparatus for operating a linear compressor including a reciprocating piston, the apparatus comprising:

a rectifying and filtering unit for converting an alternating current into a direct current;

an inverter for inverting the direct current outputted from the rectifying and filtering unit into an alternating current of a desired frequency for operating the linear compressor;

a position sensor for detecting a position of the piston of the linear compressor and outputting a position signal in accordance with said detection;

a current detector for detecting a current running through the linear compressor and outputting a current signal in accordance with said detection; and

a controller for receiving the current signal outputted from the current detector and the position signal outputted from the position sensor and outputting a pulse width modulating signal to control the inverter.

2. The apparatus of claim 1, wherein the controller, comprises:

a peak value detector for detecting a peak value of the position signal outputted from the position sensor;

an amplifier for amplifying the detected peak value of the position signal to a selected, predetermined voltage level;

a phase differential detector for detecting a phase differential between the position signal outputted from the position sensor and the current signal outputted from the current detector;

a converter for converting the phase differential detected by the phase differential detector into a frequency signal; and

a pulse width signal generator for receiving a voltage outputted from the amplifier and the frequency signal outputted from the converter and outputting the pulse width modulating signal to the inverter.