With the development of frequency measurement technology, the measurement method of frequency meter is divided into measuring frequency method, time interval, phase conversion frequency measurement method, digital recruitment method, interpolation frequency measurement method and frequency mixing frequency measurement method. In the digital frequency measurement method, two improvements have been made in the frequency measurement method of equal precision: on the one hand, the measurement accuracy is improved by modifying the original reference clock signal value without increasing the working frequency of the system and prolonging the measuring threshold time; from another perspective, the preset threshold time band is eliminated by the adaptive frequency division of the measured signal. The shortage of the system simplifies the synchronous logic circuit and improves the reliability of the system.
The commonly used digital frequency measurement methods include direct frequency measurement and indirect frequency measurement. The direct frequency measurement method is suitable for digital circuit implementation. The basic principle is to select the gate signal, transform the measured signal into the same frequency periodic pulse signal, and then fill the selected pulse gate time with the measured pulse signal. The pulse number of the measured pulse signal in the gate time is counted by counting circuit, and the measured pulse frequency is obtained.
The SYN5636 type general counter has the "multiple parallel counting method": Based on multi-channel parallel processing capability, fast computation speed, low cost and high integration FPGA, it uses multiplex different frequency reference signals to count; absolute error can only be 1, and the highest accuracy count result is selected. When implemented, a high-speed comparator module is built by using a wideband amplifier and a high-speed comparator. The FPGA is used as the frequency measuring module. The control module is composed of single chip microcomputer, LCD display screen and keyboard, and the Verilog parallel programming is used to realize the "multi channel parallel counting method". It is expected to achieve high precision measurement of the frequency of 1 Hz to 199M Hz sinusoidal signal, and realize the time interval measurement of the other signal and the duty cycle measurement of the pulse signal.
Here are a few factors that affect the price of the frequency meter.
R & D cost
The R & D cost accounts for about 25% of the frequency meter. The frequency meter is a small-scale product. The world does not use much. A large factory or a scientific research institution only needs one or two clock servers. Ordinary households or company units do not need frequency meters, which leads to less frequency and fewer users. There are no more than 10 manufacturers of the meter, and there are fewer and less than 5 manufacturers. This leads to the high cost of R & D of the frequency meter.
Two, hardware cost
The cost of hardware accounts for about 25% of the frequency meter. If imported devices are used for production, the cost will increase significantly, and hardware will account for about 70% of the cost. The hardware cost of cymometer mainly includes chassis, circuit boards, devices, power supplies, connectors and oscillators. With the influence of China's capacity, all kinds of prices are rising. With the case, steel and other commodities are rising, which leads to the rise of the chassis factory. In addition, environmental supervision has led to a substantial increase in the cost of the entire chassis by more than 60%. However, as the terminal manufacturers of frequency meters, these prices are hard to pass on to customers, so they can only reduce profits continuously, so that industry is not easy to do.
Four, marketing costs
The marketing cost accounts for about 10% of the clock server price. At present, most users use the two selling schemes under the online and offline, and the line is a regular treat, dinner, gift giving and so on. This is not the case. It is mainly said that the sale on the line is mainly through network marketing. The cost of network marketing has been greatly raised at present, and the cost is almost the same under the line, which is why. Many giants are turning to offline stores.
Five. Summary of price composition
At present, the frequency meter price wants to be reduced, one is to reduce taxes (which is unlikely), the other is to start with R & D, start from the cost of hardware and management costs, so it is recommended that users of satellite clock should be purchased. It is better to directly purchase the clock of direct selling manufacturers, and choose less advertising manufacturers, preferably three goods, and then purchase. 。
Six. The influence of raw materials on the frequency meter price.
The price of raw materials is rising, and the price of finished products will rise along with the law of market development. This practice has a certain impact on the customers directly facing our company. And near the end of the year, some of the raw materials have doubled, which has been a bit unprepared for manufacturers who have been applying to cope with this surge. If the price of the GPS network clock server remains unchanged or falls, the profits of the manufacturers eroded in the middle will have a mechanical impact on the stable development of the enterprise.
Seven, the impact of service cost on the frequency meter price.
As a service enterprise, we set up a special department for the frequency meter's pre sale, after sale and so on. Before sale, we have a marketing department and after-sale department, which are responsible for various pre-sale and after sale services, and provide end to end services for customers.
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