Wireless Charger
Wireless Mobile Charging is one of the trending topic in the field of electronics thus we also decided to build a Wireless Mobile Charger Circuit Diagram using various commonly available components. The project Wireless Mobile Charger Circuit Diagram posted here can deliver 271mA at 5.2V so you charge mobile phone and also can be used to drive low power load such as LED1 and LED2 as shown .
Working Principle of Wireless Mobile Charger:
Wireless Mobile Charger uses inductive coupling principle. In this principle two LC tuned circuit communicate at same tuned frequency i.e. tuned frequency of transmitter must be equal to tuned frequency of receiver. Here, we had use LC tuned to produce and transfer magnetic field which is received by another LC tuned circuit.
Circuit Description of Wireless Mobile Charger Circuit Diagram
For simplicity and better description, we have divided Wireless Mobile Charger Circuit Diagram into to section i.e. transmitter circuit and receiver section.
Transmitter Circuit for Wireless Mobile Charger Circuit Diagram: – The transmitter circuit of Wireless Mobile Charger Circuit Diagram is shown in figure 1 and is built around timer IC 555, a general purpose NPN transistor BC547, N-channel MOSFET IRF540N, LC tuned circuit and a 5-volt series voltage regulator 7805.
Let us first talk about what tuned circuit is? In the above circuit, we had used tuned collector oscillator (L1 with C1 and C2). Tuned collector oscillator uses a parallel L-C circuit in the collector circuit as the load and this circuit basically determines the frequency of oscillation. The output voltage developed across the tuned circuit is inductive coupled to the base circuit.
Timer IC 555 is used here for pulse generation thus it is arranged in astable multivibrator mode. The output of IC 555 (pin 3) is connected to base of general purpose transistor T1 which is use to drive the MOSFET T2. The MOSFET T2 is used to switch the L-C tuned circuit which further transmit oscillating magnetic field.
Series voltage regulator IC2 is used to provide operating voltage for entire circuit (+5V) from +12V as shown in figure.
Receiver Circuit for Wireless Mobile Charger Circuit Diagram: – Receiver circuit shown in figure 2 is built around LC tuned circuit (L2 with C7 and C8), a current regulator (buck and boost) IC MC34063, Schottky diode (1N5819) and few passive components. The transmitted oscillation magnetic field is detected by L-C tuned build around inductor L2 with capacitors C7 and C8 which further changed to DC voltage using bridge rectifier BR1 and filtered using capacitors C9 and C10.
The ripple free DC voltage is now given to buck/boost IC, configured into buck regulator mode. The output voltage is further filtered using L-C filter and is connected to LED through current limiting resistor R9 and R10.
Math’s involves in Wireless Mobile Charger Circuit Diagram
The entire calculation shown below is done by considering the parts list value in this circuit.
Transmitter Circuit: – As the 555 is wired in astable multivibrator thus we have to calculate pulse oscillation.
Charging time = 0.693x(R1+R2)xC3
Discharging time = 0.693xR2xC3
Oscillating Frequency of 555 =
LC Tuned Frequency
Where L = L1 = 180µH
C = C1 + C2 = 0.1µF + 0.1µF = 0.2µF
Therefore,
Receiver Circuit: – LC tuned frequency must be equal to transmitter tuned frequency 26 KHz. Thus,
Where, L = L1 = 195 µH
C = C7 + C8 = 180nF + 12nF = 192 nF
Output Voltage
Vref of IC3 = 1.25V
R7 = 15 KΩ
R6 = 4.7 KΩ
Therefore, Output Voltage (VO) = 5.2V
Output Current = 271mA
Input Voltage = 12V
Input Current = 180mA
PARTS LIST OF WIRELESS MOBILE CHARGER CIRCUIT DIAGRAM
Resistor (all ¼-watt, ± 5% Carbon)
R1, R4 = 1 KΩ
R2, R3 = 3.3 KΩ
R5 = 150 Ω
R6 = 4.7 KΩ
R7 = 15 KΩ
R8 = 0.33 Ω
R9, R10 = 68 Ω
Capacitors
C1, C2 = 0.1 µF (Polyester Capacitor)
C6 = 0.1 µF (Ceramic Disc)
C3, C4, C9 = 0.01 µF (Ceramic Disc)
C5 = 100 µF/25V (Electrolytic Capacitor)
C7 = 180 nF (Polyester Capacitor)
C8 = 12 nF (Polyester Capacitor)
C10, C12, C13 = 220 µF/25V (Electrolytic Capacitor)
C11 = 470 pF (Ceramic Disc)
Semiconductors
IC1 = NE555 (Timer IC)
IC2 = LM7805 (Series Voltage Regulator, 5V)
IC3 = MC34063 (Buck/ Boost Regulator IC)
D1 = 1N5819 (Schottky Diode)
T1 = BC547 (General Purpose NPN Transistor)
T2 = IRF540N (N-Channel MOSFET)
BR1 = DB107 (Bridge Rectifier)
LED1, LED2 = 1-watt LED