A non-contact electrical
power transmission system is capable of providing a large
supply current of uniform level at an optimum transmission efficiency. The
system includes a power circuit including a power supply of providing a
high frequency voltage across a power winding, and a
load circuit for energizing a load. The
load circuit is composed of a secondary winding, a matching
capacitor, a
rectifier, and a
choke coil. The secondary winding is magnetically coupled to the power winding so as to generate an induced
high frequency voltage and to provide a
leakage inductance to the
load circuit. The matching
capacitor is connected across the secondary winding to be cooperative with the
leakage inductance and with the secondary winding to form an oscillatory circuit which provides an oscillating
voltage across the matching
capacitor for generating a
supply current being fed through the
rectifier and the
choke coil to the load. The matching capacitor is selected to have a specific
capacitance such that the oscillating voltage reaches its extreme each time the inducted
high frequency voltage reverses its polarity. The
choke coil is connected in circuit to smoothen the
supply current. Thus, the supply current of uniform level can be fed to the load, reducing a possibility of incurring a
noise on the supply current, yet minimizing an impedance between the supply circuit and the load circuit for realizing an optimum efficiency of converting the high frequency voltage into the supply current.