Device and method for detecting zero crossing and voltage amplitude from single pulse signal

• US 8,058,852 B2
• Filed: 04/22/2009
• Issued: 11/15/2011
• Est. Priority Date: 04/23/2008
• Status: Active Grant

• Current Assignee: Woongjin Coway Company Limited
• Original Assignee: Woongjin Coway Company Limited
• Inventors: Baek, Ju Hyun, Byean, Man Ho, Kang, Tae Kyung
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US12/428,420
• Publication Number:
  US 20090267575A1
• Time in Patent Office: 937 Days
• Field of Search: 323/234, 323/235, 323/318, 323/319, 363/21.03
• US Class Current: 323/235
• CPC Class Codes: G01R 19/04 Measuring peak values or amplitude or envelope of ac or of pulses
• CPC Class Codes: G01R 19/175 Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
• CPC Class Codes: H03K 5/1536 Zero-crossing detectors in measuring circuits G01R19/175

Abstract

A device and method for detecting a zero crossing and voltage amplitude of a commercial power source voltage inputted to an electronic device, from a single pulse signal are disclosed. The apparatus for detecting a zero crossing and a voltage amplitude from a single pulse signal includes: a first calculation unit that compares the commercial power source voltage to a first reference voltage to determine whether or not the commercial power source voltage is smaller than the first reference voltage; a second calculation unit that compares the commercial power source voltage to a second reference voltage smaller than the first reference voltage to determine whether or not the commercial power source voltage is larger than the second reference voltage; a pulse output unit that outputs a pulse if the commercial power source voltage is smaller than the first reference voltage but larger than the second reference voltage; and a detecting unit that detects a zero crossing and a voltage amplitude by analyzing the pulse which has been outputted from the pulse output unit.

Claims

1. An apparatus for detecting a zero crossing and a voltage amplitude of a commercial power source voltage inputted to an electronic device, the apparatus comprising:

a first calculation unit that compares the commercial power source voltage to a first reference voltage to determine whether or not the commercial power source voltage is smaller than the first reference voltage;

a second calculation unit that compares the commercial power source voltage to a second reference voltage smaller than the first reference voltage to determine whether or not the commercial power source voltage is larger than the second reference voltage;

a pulse output unit that outputs a pulse if the commercial power source voltage is smaller than the first reference voltage but larger than the second reference voltage; and

a detecting unit that detects a zero crossing and a voltage amplitude by analyzing the pulse which has been outputted from the pulse output unit.

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

an interrupt generating unit that generates an interrupt when the pulse which has been outputted by the pulse output unit dies;

a time checking unit that checks a time duration from when the pulse which has been outputted by the pulse output unit dies to when the pulse output unit outputs a first different pulse afterward;

a comparing unit that compares the time duration checked by the time checking unit to a pre-set reference time; and

a discriminating unit that discriminates that there is a zero crossing within the time duration checked by the time checking unit if the time duration checked by the time checking unit is shorter than the pre-set reference time, or discriminates a voltage amplitude if the time duration checked by the time checking unit is longer than the pre-set reference time.

3. The apparatus of claim 2, wherein the discriminating unit discriminates such that the zero crossing exists at a middle point of the time width checked by the time checking unit.

4. The apparatus of claim 2, wherein the discriminating unit discriminates the input voltage amplitude by obtaining a time point at which the pulse which has been outputted by the pulse output unit dies and a time point at which the pulse output unit outputs the first different pulse afterward.

5. The apparatus of claim 2, wherein the pre-set reference time corresponds to a half period of a waveform obtained by performing full wave rectification on the commercial power source voltage.

6. A method for detecting a zero crossing and a voltage amplitude of a commercial power source voltage inputted to an electronic device, the method comprising:

comparing the commercial power source voltage to a first reference voltage to determine whether or not the commercial power source voltage is smaller than the first reference voltage;

comparing the commercial power source voltage to a second reference voltage smaller than the first reference voltage to determine whether or not the commercial power source voltage is larger than the second reference voltage;

outputting a pulse if the commercial power source voltage is smaller than the first reference voltage but larger than the second reference voltage; and

detecting a zero crossing and a voltage amplitude by analyzing the outputted pulse.

7. The method of claim 6, wherein the detecting of a zero crossing and a voltage amplitude comprises:

generating an interrupt when the outputted pulse dies;

checking a time duration from when the outputted pulse dies to when a first different pulse is outputted afterward;

comparing the checked time duration to a pre-set reference time; and

discriminating that there is a zero crossing within the checked time duration if the checked time duration is shorter than the pre-set reference time, or discriminating a voltage amplitude if the checked time duration is longer than the pre-set reference time.