With the rapid development of electronic technology, the number of people using smart phones in the world is increasing. By 2017, 69% of the world's people will use smart phones. At present, cable connected charging is widely used. The cable interface of this charging method will have poor contact for a long time. Moreover, a charger is not widely applicable. Different chargers need to be used according to the types of electronic products. It is very troublesome to find appropriate interfaces and wiring when charging. The charging of various portable electronic products is a headache. In order to improve the above phenomena, we need to develop a smart wireless charger scheme. Now let's learn about the electromagnetic induction Smart Wireless charger scheme!

The wireless charger scheme uses the principle of electromagnetic induction. After 1N4148 rectification and filtering, the voltage U1 is compared with the reference source uo. During charging, the current of the transmitting coil increases with the increase of inductive load. The load voltage of 0.33 Ω is amplified by 23 times through the operational amplifier, the green light is on, and there is no inductive load after 10 seconds, so it will shut down automatically; Press the reset button, U1 is much brighter than uo colorful light, indicating that it is charging; When no-load or full charge, U1 is less than uo, and the charger will restart. The specific circuit analysis is as follows
1) When switch S2 is disconnected, the charger is in intelligent charging as a whole. The colorful lamp flashes and UI reaches a high level. At this time, Q5 is saturated, and the voltage uceq is 0.67v, which is lower than the sum of the on voltage of Q2 and Q4 (1.34v). Q2 and Q4 constitute Darlington and cut off at the same time. After the charger is started, relay K1 is closed and K2 becomes closed at the same time. When there is inductive load, Q3 is cut off at this time, and capacitors C5 and R9 form an RC charging circuit. When the capacitor charging voltage reaches the on voltage of Q2 and Q4, Q2 is turned on to saturate Q4. When relay K1 is fully charged by the adsorbed inductive load or there is no inductive load, the green light is on, that is, UI is low level. Click the reset switch and the charger will restart. When the inductive load is fully charged (or no inductive load), the capacitor C5 is charged. At this time, after the relay is powered off, the relay K2 is closed. At this time, C5 and R13 form an RC discharge circuit to give C5 rapid discharge. Its voltage is ut.
2) During S2 shutdown, the whole charging circuit is in the process of manually cutting off the power supply.
The wireless charger has the functions of automatic induction charging and intelligent power-off after full charging. It can also charge a variety of different electronic products at the same time. It is not only suitable for electronic products with various charging voltages and capacities.
The wireless charger scheme summarizes the following advantages.
1) Low cost
The circuit is composed of a pulse generation unit, a power amplification unit, a filter unit, a comparison unit and a transmitting and receiving unit. Each unit is composed of several small components, which is simple to make.
2) One to many charging
One charger can charge multiple loads. Each household can use one charger for the whole family. With the increase of load, the work efficiency will be improved, which can not only save electricity but also reduce unnecessary costs.
3) Convenient
Compared with ordinary chargers, it not only reduces the trouble of plugging in and out, but also avoids the phenomena of inappropriate connector and poor contact. The elderly can also use it easily.
4) Intellectualization
As long as the inductive load is placed on the charger to realize the intellectualization of the charging process, it can automatically inductive charging. Through information feedback, after the inductive load is fully charged, it can automatically turn off the power supply.
The above is the scheme of electromagnetic induction intelligent wireless charger. If you need more information, you can contact us at any time!