Service life of battery using radio frequency card door lock technology

As an electronic door lock, it is required to use batteries that are easily available in the market. Now, the No.5 alkaline dry battery is generally used. From the perspective of cost and environmental protection, the longer the service life of the battery, the better, and the fewer the battery sections. From the perspective of industry manufacturers, the service life of batteries ranges from 5 days to 18 months, which mainly solves the problem of low energy consumption of locks. Are you embarrassed? What? The main problem of battery-saving and 6-battery lock is whether the design of the driving part and electronic part of the lock body is reasonable and easy to solve. The micro-power consumption of lock circuit is the technical difficulty of radio frequency card electronic door lock. The following is a further analysis of this problem.

In the design of low power system, the low power design of the system is divided into two aspects: 1, inherent low power consumption, and 2, control low power consumption. On the one hand, the system design is not good, and the power consumption will go wrong.

The so-called inherent low power consumption means that all electronic components used are "low power consumption" components, and the common feature of most low power consumption devices is low-voltage power supply. In terms of circuit design, it is necessary to consider that the power consumption of components should be as low as possible in similar devices under different system States. For example, Epson in Japan and TI in the United States have a large number of optional devices in this respect. If we can't do a good job in the essential low power consumption, the power consumption problem of the system can't be discussed.

The so-called problem of controlling low power consumption is to minimize the total power consumption of the system by controlling the power supply of each part when the system is working. If some controllable parts in the system are ignored, the power consumption of the system will increase. For example, if the pull-up part is not controlled in the switch signal detection of the system, it will consume a long power when the switch is in the state.

Aiming at the lock of radio frequency card, the low power control problem is discussed. Once the components are selected, the problem of low power consumption of the system mainly focuses on how to minimize the control low power consumption. Some designers use ammeters to measure the actual power consumption of the system, but not the power consumption of the system. Because different parts of the circuit work at different times, the average power consumption of the system is not easy to measure. Another problem is that the measured value does not represent the real power consumption (the choice of measuring tools) when the large current works instantaneously, so the average power consumption of the system must be designed through theoretical calculation in the initial stage of this part of design. Radio frequency card electronic door lock is in the working mode of static waiting for card reading most of the time. In many electronic door locks, the power consumption of card reading and driving motor is similar, but this part has little effect on the service life of the battery due to the limited number of times. The electronic door lock spends more than 99.5% of its time waiting to read the card, and the average power consumption in this state determines the service life of the battery.

Because the door lock can't read the card at all times (it consumes too much power), there must be a detection method to detect the card approaching the door lock. Considering the cost and power consumption, infrared detection is the first method to solve this problem at present. At present, electronic door locks on the market basically adopt this method. Under normal circumstances, the user will not feel pause when testing five times a second. If we only consider power consumption and reduce the number of tests, it will make people feel that the lock responds slowly. The power consumption of the detection circuit is tens of milliamps (which is very large for the battery), so this part of power consumption must be controlled (accounting for about 50% of the average power consumption of the system). It is difficult to truly reflect the power consumption of this part with general measuring tools, so it must be taken into account when designing, otherwise you will find that the actual service life of the battery is not like your design parameters.