Abstract: A switching circuit (Q11, Q12, D11, D12, D13, L11, L12) is repetitively configured to charge an energy transfer capacitance (C11) from an electrical supply (V11) and then inject a discrete pulse of energy into a resonated load circuit by discharging the capacitance. The load circuit is formed by a resonating capacitance (C12) and an inductive load device (T11, R11), eg motor, or induction heating or power transfer device. Energy circulates in the load circuit at or near to its natural resonant frequency. There is no injection of energy into the load circuit while energy for charging the transfer capacitance is being delivered from the supply to the switching circuit. During injection, the two capacitances and the inductive load device may be connected together in parallel or in series, or the transfer capacitance may be connected in series with the inductive load device but not the resonating capacitor.

Abstract: An electromagnetic field energy recycling circuit recovers energy from collapsing magnetic fields, stores recovered energy as charge on a capacitance, and subsequently re-uses stored recovered energy to establish a magnetic field. Capacitance and inductance are sequentially connected in various configurations to recycle the energy by a discontinuous resonant energy transfer. In a magnetizing configuration, a magnetic field is established by transfer of energy from a capacitance to an inductance. In a recovery configuration, a capacitance is charged with energy recovered from the inductance on collapse of the magnetic field. In a third configuration, recovered energy stored by the capacitance is held until required for establishing a magnetic field. During magnetizing, the capacitance voltage drops by at least 50%: preferably to zero. During recovery, current flowing in the inductance falls to zero. The circuit drives electromagnetic devices, e.g.