With the continuous development of society, the continuous improvement of living standards and the increasing work intensity, mobile phones as a portable mobile communication device have become more and more essential for people's daily life. With the widespread promotion of mobile phones, the consumables of related consumables will also rise. The charger (power adapter) is a must-have for the battery power of mobile phones, and its usage is no less than that of mobile phones. How to reduce the power consumption of the charger and the power consumption in the full state will become a problem that the whole society must face.
Most mobile phone users save time after charging their mobile phones, and they don’t pull out the plugs for the next charge. This wastes power and creates huge security risks. According to recent survey data from Nokia, the mobile phone consumes more than 60% of its total energy usage in no-load mode (the charger is plugged into a wall outlet but not connected to the mobile phone). More than 3/4 of the power consumption is caused by the user not charging the charger after the mobile phone is fully charged. At present, there are more than 600 million mobile phone users in China, which is a great waste. According to preliminary statistics, the mobile phone will not be plugged after charging, and the annual power consumption will exceed 2 billion kWh, which is equivalent to 4% of the power generated by Gezhouba Hydropower Station.
To this end, the author designed a charger that can automatically power off the mobile phone charger to achieve the purpose of zero power consumption of the original coil when the mobile phone charger is empty and the battery is full, to save resources and start from the side.
1 program design and hardware components
1.1 Scheme design
Compared with the existing power-off charger, the advantage of this product is that it can not only automatically power off when fully charged, but also automatically power off when the mobile phone is manually unplugged, to achieve automatic power-off. Figure 1 shows the internal circuit diagram.
Working principle: After connecting the charger to the mobile phone and the socket, the voltage is adjusted by the resistor, and enters the voltage comparator with a small value to output a rated value, which is the normal charging of the mobile phone. When the mobile phone is fully charged, there is a voltage comparator that is larger than the other end voltage, and the output is 0V. At this time, the relay sucks the armature to disconnect the circuit and realize automatic power-off.
Figure 1 internal circuit diagram
1.2 Hardware components
1.2.1 Relay
The micro-relay is used to realize the on-off control of the circuit. When not fully charged, the upper armature pulls in and the mobile phone is normally charged; when the charger is fully charged, the upper armature is disconnected, causing the circuit to be disconnected instantaneously to achieve automatic power off.
1.2.2 Voltage Comparator
Use the comparator voltage comparator to achieve the desired voltage output. The voltage comparator can be thought of as an op amp with a magnification close to "infinity." Function of the voltage comparator: Compare the magnitude of the two voltages (using the high or low level of the output voltage to indicate the magnitude relationship between the two input voltages):
When the "+" input voltage is higher than the "-" input, the voltage comparator output is high;
When the “+†input voltage is lower than the “-†input, the voltage comparator output is low.
One end of the voltage comparator is connected to the input voltage point and the other end is grounded. A reference voltage of 0.2V is preset, and when the input voltage is less than 0.2V, the voltage u1 "0.2V" is outputted through the voltage comparator, and a suitable voltage is output to make the circuit operate normally. When the charging is completed, the voltage of the comparator is 0.2V, the output voltage of the comparator is 0V, and the armature of the relay is disconnected, so that the circuit is instantaneously disconnected, and the automatic power-off is realized.
1.2.3 Diode
The circuit uses multiple diodes to prevent current reflow, and its respective functions are different.
(1) Adopt 1N4007 type diode.
Function: 1. When the mobile phone is fully charged, the performance of diode diode conduction is used to prevent current from flowing backwards. (2) When the positive and negative terminals of the mobile phone battery are reversed, the battery can be protected and the service life can be extended.
Adopting IN4148, it is a small high-speed switching diode with relatively fast switching. It is widely used in single-pass isolation for circuits with high signal frequency, and is commonly used in communication, computer boards, TV circuits and industrial control circuits.
1.2.4 capacitance
Use 22u/10V capacitor to control the stability of the relay action. Capacitance can store the charge under a given potential difference. When the mobile phone is not full, the capacitor stores the charge. When the battery is about to be full, the capacitor discharges the charge, the circuit current is stable, and the relay does not swing the armature up and down due to the unstable current. , to facilitate automatic power off.
1.2.5 Resistance (R9/10K)
Here, a 10 kΩ resistor is used in parallel with the comparator to prevent the relay from swinging up and down due to current instability, which is beneficial to automatic power-off.
1.2.6 reset switch
In order to reduce the user's troubles, the reset switch (SW-PB) is selected to achieve automatic reply. The principle is as follows: when the switch is pressed for a moment, the circuit is turned on instantaneously. When the switch is released, the switch is disconnected from the circuit, and the circuit is instantaneously turned on to make it work normally.
2 Instructions for use
(1) Always leave space around the power adapter. Do not use the power adapter in a place where air circulation is poor.
(2) When connecting or disconnecting the power adapter, always grasp the sides of the power adapter, and do not let your fingers touch the metal part of the plug.
(3) Before connecting the USB cable to the power adapter, make sure that there is no foreign matter in the USB port of the power adapter.
(4) The power adapter is a high voltage device and should not be removed for any reason, even when the power is off.
3 application objects
The design method is simple and suitable for all kinds of people. Just press the switch before charging, and you can realize the automatic power-off function without any trivial operation. Moreover, since it can automatically power off when it is empty and the battery is saturated, it saves energy and saves economic expenses while providing convenience for the majority of users.
Landscape Lamp lighting is decorative light source configuration of city garden landscape,cultural and recreational square and large-scale social activities widely used and essential,is a decorative lighting products.Rod material diverse use of flexible,light,sound,light,electricity three-in-one,structure and morphology in different poses and with different expressions,beautify,lighting,green organic combination,light and shadow,perfect crystal lamp and art.
1. Decorative landscape lighting products.Design style or abstract avant-garde such as artistic sculpture, or simulation realism such as natural normal elements can beautify the lighting environment and become a symbol of the national culture in a city.Whether it is a large cultural square or a fashion building community, there is a reason for it.Excellent viewing and use value.
2. applicable place:Park, courtyard and upscale residential area, road side, commercial pedestrian street, leisure plaza, scenic tourist area, etc.
3. material description:Steel lamp body, the whole high quality hot dip galvanizing after electrostatic spraying, not rusting, aging, surface clean.The light source is metal halide lamp, energy-saving lamp and LED.
Landscape Lamp
Landscape Lamp,Landscape Lamp Post,Landscape Lampshade,Landscape Lamps
Jiangsu chengxu Electric Group Co., Ltd , https://www.chengxulighting.com