Method and system for improving timing precision of common timer

Abstract

The invention discloses a method for improving the timing precision of a common timer. The method comprises the following steps of: calibrating the vertex frequency of a crystal oscillator through an error correction module of the crystal oscillator; a crystal oscillator working environment temperature acquisition module is used for detecting the working environment temperature of the crystal oscillator in real time; the crystal oscillator frequency deviation at any temperature is calculated; calculating an accumulated error of timing; determining the minimum correction time according to the timing pulse; correcting a timing error by adopting the minimum correction time; and recalculating the initial accumulative error. The invention also provides a system for improving the timing precision of the common timer. The system comprises a crystal oscillator error correction module and a crystal oscillator working environment temperature acquisition module. The method and the system for improving the timing precision of the common timer have the following advantages and effects: aiming at the current situation of the common timer, the invention provides the method and the system for improving the timing precision of the common timer so as to effectively improve the timing precision of the common timer.

Description

technical field [0001] The invention relates to the technical field of timers, in particular to a method and system for improving the timing accuracy of ordinary timers. Background technique [0002] As timing instruments and time control switches, timers are widely used in industrial and agricultural production, equipment control and daily life. At present, most ordinary timers on the market use 32768HZ quartz crystal oscillators as timing sources, and there is a common problem, timing accuracy Generally not high, the general accuracy is ±2S / day at 25°C, considering the temperature change of the use environment, its actual accuracy is ±3-7S / day, in the case of extreme temperature -25°C or 70°C, its daily The error exceeds 10S / day. Therefore, the annual error of the ordinary timer (time control switch) is generally about ±30 minutes, and its annual error may reach 60 minutes in some special occasions. The existence of this error brings a lot of inconvenience in practical a...

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Problems solved by technology

The existence of this error brings a lot of inconvenience in practical application

[0003]The reason why the timing accuracy of ordinary timers is not high is that the error of the 32768HZ crystal oscillator itself is generally ±10ppm. If the matching capacitor is not adjusted at 25°C, it will cause normal temperature The lower error exceeds ±2S / day; the second is the influence of temperature on the crystal oscillator. Due to the influence of the cutting process, the temperature curve of 32768HZ is an inverted parabola with the apex of 25±5℃, F=F0+k(Ta-Tx)×(Ta- Tx) (k=-0.037±0.005, Ta=25±5°C, Tx is any temperature, F0 is the peak frequency), if there is no temperature compensation, the error exceeds 8S per day at a temperature of 75°C

If you want to improve the timing accuracy of the timer, generally use a temperature-compensated 32768HZ crystal oscillator or a temperature-compensated RTC. The accuracy at 0-50°C can achieve 0.3S / day, and the accuracy at -25-70°C is within 0.5S / day. Due to the price The reason is that ordinary timers do not use temperature compensation measures.

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