Wireless power receiver circuits and methods for use in wireless power transfer systems are provided for providing a constant current or voltage, depending on which is needed, to an electrical load. The wireless power receiver circuits are configured to shut down the resonant responses of the receiver circuits when electrical power is not needed by the load to reduce power consumption and avoid unnecessary heat dissipation. Additionally, a switching device of the wireless power receiver circuit that is used for shutting down the resonant response can operate at relatively low frequencies, and consequently, can be implemented using relatively low-speed, relatively inexpensive components.