Ways to improve the accuracy of a quartz timer

Quartz timer is an electronic timer widely used in various industries and our daily life, hereinafter referred to as electronic watch. The daily variance of an electronic watch is the 24-hour timing error of the continuous running time of the electronic watch. Instantaneous daily difference is the timing error that measures the running time error of an electronic watch within a specific time interval converted to 24h, and its unit is s, ms, etc. The daily difference is an important metric for evaluating clock speed. and reflect its quality. The clock runs faster or slower than the standard clock, depending on the frequency of the main oscillator used. If the actual frequency value is higher than the nominal value, it will run faster, otherwise it will be slower.

Quartz timer homeopathy is based on the frequency or beat number of the time base oscillator that makes up the clock, and the instantaneous rate is directly measured using an instantaneous rate meter or other similar instrument. The measurement time is short and the requirements for the verification/calibration environment are relatively low. Conveniently, it doubles the verification/calibration efficiency. The reason why quartz wafers can form oscillator circuits is based on their piezoelectric effect. If an electric field is applied between the two plates of the wafer, the crystal will deform mechanically; this will cause the crystal to deform. Conversely, if a mechanical force is applied between the plates, an electric field is created in the corresponding direction. This phenomenon is called the piezoelectric effect. If an AC voltage is applied between the plates, mechanical deformation vibration will be generated, and at the same time, the mechanical deformation vibration will generate an AC electric field. Generally speaking, the amplitude of this mechanical vibration is relatively small, and its vibration frequency is very stable. However, when the frequency of the applied AC voltage is equal to the natural frequency of the wafer, the amplitude of the mechanical vibration will increase sharply. This phenomenon is called piezoelectric resonance, so quartz crystals are also called quartz crystal resonators. It is characterized by high frequency stability, and the accuracy is not easy to change.

Commonly used quartz timer chips can cause errors

1. It comes from the factors of the crystal itself, such as the cutting process, the influence of temperature;

2. It comes from the circuit, the value of the oscillating capacitor, the stray capacitance and the error caused by the temperature drift of the capacitor. The daily error of the traditional electronic watch is determined by the quartz crystal, and its production method is to check the quartz crystal before installation, and put it into production and use within a certain measurement accuracy range. 

Once a quartz timepiece is assembled into a final product, its day-to-day errors are fixed and cannot be modified or calibrated. When a quartz timepiece uses a crystal oscillator composed of a quartz crystal as its timing reference, the degree of accumulated error varies. Therefore, for equipment that requires high time precision, there are very strict requirements on the quality of the crystal, so the cost is high. Additionally, existing time calibration methods eliminate errors by aligning with a standard clock each day. The process is cumbersome and manual operations will inevitably lead to some errors.