According to the different ways of power supply, advertising machine can be divided into utility advertising machine, non-utility advertising machine and dual-mode power supply advertising machine. The other two types of advertising machines are mainly powered by utility power, while the other two types of advertising machines are equipped with targeted standby power supply to meet the power supply requirements of different applications and fields. The appearance of the backup power supply is designed to fully comply with the overall design of the product at the same time can do the installation and replacement of the battery at any time.
Design requirements:
I. LCD advertising machine backup power supply design requirements:
As the advertising machine itself has a small working current, but the required power supply time is very long, the general choice of high-capacity battery cells combined into a high-capacity finished battery to meet the requirements of its power supply time, while needing to have high security. Therefore, the LCD advertising machine backup power solution uses Sanyo UR18650F cell combination to achieve 10Ah charge capacity.
1) Lithium battery pack type design requirements: 18650-2S4P/10Ah/7.4V.
2) Circuit design requirements:
1, single cell overcharge protection voltage: 4.28±0.25V
2, single section overcharge recovery voltage: 4.15±0.50V
3、Single section over discharge protection voltage: 3.00±0.08V
4、Single section over discharge recovery voltage: 3.10±0.10V
5、Combination battery overcurrent protection value (10ms): 4~8A
6, the combination of battery over-temperature protection value (recoverable): 70±5℃
7, the finished battery should have a short circuit, reverse charge protection function.
(3) cycle life design requirements: 300 ~ 500 times (in line with the national standard charge and discharge standards)
(4) battery appearance size design requirements: reference battery shell, can be customized according to customer requirements.
Second, the LCD advertising machine backup power design program:
(1) protection board (PCM): mainly for rechargeable lithium battery pack is designed to protect the circuit, due to the chemical characteristics of the lithium battery itself, the need to provide intelligent power calculation, overcharge, over discharge, short circuit, overcurrent and other protection functions to avoid causing combustion, explosion and other dangers.
2）Protection IC: The main protection function chip of the backup power design solution, which monitors the online function of the battery cell in time, so that the battery cell works in a safe, stable and efficient range.
(3) Temperature switch: mainly designed for the temperature protection function. When the temperature of the battery itself reaches 70±5℃ range due to other abnormal problems, the temperature switch is activated for temperature protection
4）18650 Li-ion cell: UR18650F/2500mAh/3.7V Li-ion cell (SANYO)
5) Field effect tube (MOSFET): MOSFET tube, in the protection circuit to play a switching role, always so that the voltage at both ends of the load will not rise and will not fall, to ensure voltage stability.
6) Battery package: (shell)