Tag Archives: BS170

Wireless power transmitter and receiver//

working model of wireless power transmitter and receiver.  The Transmitter and Receiver coils with capacitors connected to each coils, forms a tank circuits that resonates with a frequency of f = 1/(2π√(LC)), if the two resonant circuits resonating at the same frequency and were brought to close, the energy  transferred from transmitter to receiver…

so, the frequency of transmitter and receiver must be tuned for different inductance values of transmitting coil and the receiver coil…

L1 = 10turns , 160mm dia  of 18SWG (transmitter coil) = 35.826uH

L2 = 20turns, 160mm dia of 18SWG(receiver coil) = 131.48uH

i have calculated the inductance of Tx and Rx coils using oscilloscope and the pulse generator.

paper work:

paper work



circuit is simple, apply a pulse of 20KHz, 30% duty cycle of 5Vpp  use MCU or analog chip or opamps or schmitt trigger circuit.

BS170 is a lower power MOSFET serves as a gate driver for the power MOSFET IRFP250N,  D1 (1N4735A) a 6.2V zener so the gate to source voltage (Vgs) is always less than 6.2V.   L1 and C1 forms a tank circuit that resonates with a frequency of 59.457KHz. (transmitter )

resonating frequency   of both transmitter and receiver must be same f1 = f2 = 59.457KHz

therefore     1/(2π√(L1C1)  = 1/(2π√(L2C2)

(L1C1)  =  (L2C2)

therefore C2 = 54.4965nF

receiver must be detuned to the frequency using LC tank  formed by L2 = 131.48uH  therefore C2 = 54.4965nF (no 50nF, 1nF cap’s in my lab so i used 2 of 100nF  capacitors connected in series that forms equivalent capacitance of 50nF which is little close to 54.5nF.

note:  the capacitors must be type of polyster or polysulphide and atleast 200V rated..

here is my setup: