CN101303376A - Method and apparatus for compensating voltage zero-cross detection - Google Patents

Abstract

The invention discloses a zero passage voltage detection and compensation method which is characterized by including the steps that: a timer is started up after zero passage voltage interrupt signals are received and the timing time of the timer is the offset time of a zero crossing point of voltage; the interrupt point of the timer is determined as the zero crossing point of the voltage after the interrupt signals of the timer are received. The invention also discloses a corresponding zero passage voltage detection and compensation device. The method and the device of the invention can accurately detect an absolute zero crossing point of the voltage without adding hardware cost and can be applied to occasions demanding very accurate zero passage signals.

Description

A kind of voltage zero-cross detects compensation method and device

Technical field

The present invention relates to the voltage zero-cross detection technique, relate in particular to a kind of voltage zero-cross and detect compensation method and device.

Background technology

In electronic technology, zero passage is meant alternating voltage in the change procedure of voltage, and change in voltage arrives that of zero, can utilize this zero crossing to come generally to be used for timing and to open SCR control as reference point in line design usually.The method and the circuit that have occurred a lot of zero passage detection therefrom.Fig. 1 and Fig. 2 are two kinds of zero passage detection circuits that utilize diode and triode to realize respectively relatively more commonly used in the prior art, in above circuit, when zero crossing arrives, produce the zero passage look-at-me, under the situation of interrupting over the single-chip microcomputer, send in the single-chip microcomputer by the I/O mouth of single-chip microcomputer.

Above-mentioned prior art problems is, adopt these two kinds of wireline inspection to the zero cross signal situation that hysteresis all can be arranged basically or postpone, rather than absolute zero passage.Under less demanding situation, as timing, drive the controllable silicon of resistive load etc., problem is little, requires zero cross signal occasion very accurately but can not be applied in.

Summary of the invention

Technical matters to be solved by this invention is: provide a kind of voltage zero-crossing signal to detect compensation method, this method can detect the absolute voltage zero crossing exactly, need not to increase hardware cost, can be applicable to zero cross signal requirement occasion very accurately.

The further technical matters to be solved of the present invention is: provide a kind of voltage zero-crossing signal to detect compensation system, this device can detect the absolute voltage zero crossing exactly, need not to increase hardware cost, can be applicable to zero cross signal requirement occasion very accurately.

For solving the problems of the technologies described above, the present invention adopts following technical scheme:

A kind of zero passage voltage detection and compensation method is characterized in that, may further comprise the steps:

After receiving the zero passage voltage look-at-me, start timer, the timing of described timer is the voltage over zero shift time;

After receiving the look-at-me of timer, this timer point of interruption is defined as voltage over zero.

Correspondingly, the present invention also adopts following technical scheme:

A kind of zero passage voltage detection and compensation device, this device includes:

Zero passage Interrupt Process unit is used for after receiving the zero passage voltage look-at-me, starts timer, and the timing of described timer is the voltage over zero shift time;

The zero crossing determining unit is used for after receiving the look-at-me of timer, and this timer point of interruption is defined as voltage over zero.

The invention has the beneficial effects as follows:

On the basis of embodiments of the invention by zero passage circuit commonly used in the prior art, utilize the timer internal and the external interrupt of single-chip microcomputer itself to work in coordination, zero passage look-at-me to the outside is revised, thereby obtain zero passage look-at-me accurately, thereby increase under the situation of hardware cost need not, can be applicable to zero cross signal requirement occasion very accurately.

The present invention is described in further detail below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 is the circuit theory diagrams that utilize the zero passage detection circuit of diode realization in the prior art.

Fig. 2 is the circuit theory diagrams that utilize the zero passage detection circuit of triode realization in the prior art.

Fig. 3 is the oscillogram of line voltage.

Fig. 4 is the zero cross signal oscillogram that zero passage detection circuit of the prior art produces.

Fig. 5 is actual zero cross signal oscillogram.

Fig. 6 is the method flow diagram of an embodiment of zero passage detection compensation method provided by the invention.

Embodiment

As shown in Figure 3, the used line voltage standard of electric equipment is 220V 50Hz usually.Because the on state characteristic of diode and triode, the forward voltage of general diode and triode are about 0.3-0.7V, therefore in real voltage zero-cross, not having rising and falling edges in the circuit illustrated in figures 1 and 2 produces, and cause zero cross signal to have some skew, with reference to figure 4, among the figure, each waveform is not the 10ms of standard, and might be offset a bit, and as 9.5ms, 10.5ms etc., but the frequency of waveform still can not become, or 50Hz.

According to above-mentioned, in Single Chip Microcomputer (SCM) system, can utilize the timer internal of single-chip microcomputer itself and external interrupt to work in coordination, its outside zero passage look-at-me is compensated and corrected, obtain zero passage look-at-me more accurately.Under the situation that does not increase hardware cost, just can realize real zero passage like this, require tighter occasion just can use to zero cross signal at some.

Present embodiment is on the basis of zero passage detection circuit commonly used in the prior art, utilizes the timer internal of single-chip microcomputer itself and external interrupt to work in coordination, and the zero passage look-at-me of outside is compensated and corrected, thereby obtain zero passage look-at-me accurately.

During specific implementation, can set an external interrupt and a timer internal in single-chip microcomputer, the IO mouth of external interrupt connects circuit as depicted in figs. 1 and 2.When zero cross signal comes, A point as Fig. 4, single-chip microcomputer enters the zero passage interrupt service routine, and at this moment be not real zero crossing, real zero crossing is at the B of Fig. 5 point, the A point has been done sth. in advance 0.5ms than the B point, therefore be 0.5ms the break period of setting timer internal in the zero passage interrupt service routine, open timer internal, when the interruption of timer internal timing 0.5 has come, enter in-line interrupt service routine, arrived the B point of Fig. 5, be exactly real zero crossing, just can carry out various the operation after having found real zero crossing.Can just can find other real zero crossing by similar method, thereby realize obtaining of accurate zero cross signal.

With reference to figure 6, particularly, as follows to the process of the zero passage look-at-me single compensation correction of outside:

Step S01 is a zero passage Interrupt Process step, in this step, receive the zero passage voltage look-at-me after, start timer, the timing of described timer is the voltage over zero shift time, during specific implementation, its timing is 5ms;

Step S02 is the zero crossing determining step, in this step, receive the look-at-me of timer after, this timer point of interruption is defined as voltage over zero.

Describe an embodiment of zero passage voltage detection and compensation device provided by the invention below in detail.Present embodiment mainly includes:

Zero passage Interrupt Process unit is used for after receiving the zero passage voltage look-at-me, starts timer;

The voltage over zero determining unit is used for after receiving the look-at-me of timer, and this timer point of interruption is defined as voltage over zero.

During specific implementation, the timing of described timer is the time of zero cross signal time-delay, as 5ms.

The above is a preferred implementation of the present invention; should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the principle of the invention; can also make some improvements and modifications, these improvements and modifications also are considered as protection scope of the present invention.

Claims (4)

1, a kind of zero passage voltage detection and compensation method is characterized in that, may further comprise the steps:

After receiving the zero passage voltage look-at-me, start timer, the timing of described timer is the voltage over zero shift time;

After receiving the look-at-me of timer, this timer point of interruption is defined as voltage over zero.

2, zero passage voltage detection and compensation method as claimed in claim 1 is characterized in that, the timing of described timer is 5ms.

3, a kind of zero passage voltage detection and compensation device is characterized in that, this device includes:

Zero passage Interrupt Process unit is used for after receiving the zero passage voltage look-at-me, starts timer, and the timing of described timer is the voltage over zero shift time;

The zero crossing determining unit is used for after receiving the look-at-me of timer, and this timer point of interruption is defined as voltage over zero.

4, zero passage voltage detection and compensation device as claimed in claim 1 is characterized in that, the timing of described timer is 5ms.

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