NOVELTY - The circuit (220) has a comparison circuitry for providing a transition power characteristic threshold and for comparing input power to the transition power characteristic threshold. A switching circuitry disconnects a power supply (100) from a portable electronic device (102) and reconnects the power supply to the electronic device when the input power exceeds the transition power characteristic threshold. An available power measurement circuitry dynamically detects voltage and current being provided by a variable electrical power source.    USE - Electronic circuit for use with a variable electrical power source e.g. heat and fire powered generator, photovoltaic cell, solar cell, solar-powered electricity generating solar device, wind-powered electricity generating device, generator utilizing flowing water or kinetic motion, and fuel cell (all claimed), for providing input power, input voltage and input current to a portable electronic device. Uses include but are not limited to a smartphone, satellite phone, tablet computer, notebook computer, laptop computer, gaming device, navigation device, camera, watch and an e-reader.    ADVANTAGE - The circuit can include a voltage regulation circuitry for limiting rate of drop of voltage being supplied to the electronic device in response to the power management circuitry of the electronic device. The circuit is capable of converting output of the variable power source into controlled electricity for providing electrical energy to directly power or charge the electronic device at multiple power input levels or at a higher quantized power level without requiring ancillary batteries and without a need for the electronic device to be held on an initially-observed power input, thus eliminating a need for an intermediary rechargeable battery system to satisfy specific energy delivery requirements of the electronic device at low cost with efficient power conversion mechanisms.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of a power supply connected to a portable electronic device with an electronic circuit.    Power supply (100)    Portable electronic device (102)    Power circuitry (103)    Battery (104)    Electronic circuit (220)